Chapter 8 Thermochemistry: Chemical Energy. Chemical Thermodynamics

Size: px
Start display at page:

Download "Chapter 8 Thermochemistry: Chemical Energy. Chemical Thermodynamics"

Transcription

1 Chapter 8 Thermochemistry: Chemical Energy Chapter 8 1 Chemical Thermodynamics Chemical Thermodynamics is the study of the energetics of a chemical reaction. Thermodynamics deals with the absorption or release of energy (generally as heat) that accompanies chemical reactions. These dynamics generally give us an idea of whether a reaction will be spontaneous Spontaneous describes a process that can occur without outside intervention (i.e. changing the temperature, pressure or concentration) Spontaneity does not imply that the process occurs quickly, but rather describes a capability to proceed. If a chemical reaction is found to be spontaneous in one direction, then under the same conditions, the reverse reaction will be non-spontaneous This does not mean that the reaction cannot occur, but that it will need some outside help. Chapter 8 2 Evisdom 1

2 Energy Energy is the capacity to do work, or supply heat. Energy = Work + Heat Potential energy, PE, is stored energy; it results from position or composition. Kinetic energy, KE, is the energy matter has as a result of motion. KE = 1/2 mv 2 Units for KE: 1 Joule = 1 kg m 2 /s 2 OR 1 calorie = J Chapter 8 3 The SI unit for energy is the Joule (J) The joule is a small amount of energy so scientists generally refer to Kilojoules (kj) The calorie (cal) is another unit of energy. It is defined as the amount of energy needed to raise the temperature of 1.00 g of water by one degree Celsius Units of Energy 1 cal = J Chapter 8 4 2

3 KE, Temperature & State All substances have kinetic energy no matter what physical state they are in. Solids have the lowest kinetic energy, and gases have the greatest kinetic energy. As you increase the temperature of a substance, its kinetic energy increases. Chapter 8 5 Forms of Energy There are six forms of energy: Heat, Radiant, Electrical, Mechanical, Chemical and Nuclear We can convert among these types of energy Chapter 8 6 3

4 Thermal Energy Thermal Energy is the kinetic energy of molecular motion (translational, rotational, and vibrational). We measure this energy by finding the temperature of an object Thermal energy is proportional to the temperature in degrees Kelvin E thermal α T(K) Chemical Energy is the PE of a chemical compound where the chemical bonds act as storage containers for the energy Chapter 8 7 The System and the Surroundings The system is the specific part of the universe that is of interest to us (i.e. the reaction with reactants & products) The surroundings is the rest of the universe When performing experiments, we measure changes to the surroundings then apply those findings to the system. Energy is transferred between the system and the surroundings Energy that is transferred from the system to the surroundings has a negative sign Energy that is transferred from the surroundings to the system has a positive sign E = E Chapter 8 final -E Initial 8 4

5 State Functions AState Function is a function or property whose value depends only on the present state (condition) of the system not the path used to arrive at that condition. The change in a state function is zero when the system returns to its original condition. For non-state functions, the change is not zero if the path returns to the original condition Chapter 8 9 State Functions Here s an example with a chemical reaction: The two paths below give the same final state: N 2 H 4 (g) + H 2 (g) 2 NH 3 (g) + heat (188 kj) N 2 (g) + 3 H 2 (g) 2 NH 3 (g) + heat (92 kj) State properties include for the formation of NH 3 : temperature, total energy, pressure, density, and [NH 3 ] Non-state properties include for the formation of NH 3 : heat and reactants used Chapter

6 Work Work (w) is the application of a force (F) through a distance (d) This work produces an object s movement If the system performs work on the surroundings, the sign of w is negative. If the surroundings perform work on the system, the sign of w is positive. Work = Force Distance w = F d Units for w: Newton-meters (N-m) or Joules (J) 1 J = 1 N-m A system that contains one or more gases performs a specific type of work called PV Work or expansion work. Chapter 8 11 Expansion Work A system that contains a gas can perform work as the gas expands against an opposing pressure (P) exerted by the surroundings. This type of work is called Expansion Work or PV Work w = - P V V = V Final -V Initial 1 L atm = 101 J When a gas expands, w is negative because the system transfers energy to the surroundings When a gas contracts, w is positive because the surroundings transfer energy to the system Chapter

7 Work How much work is done (in kilojoules), and in which direction, as a result of the following reaction? Chapter 8 13 Heat Heat (q) is the energy that flows from a warmer object (higher temperature) to a cooler object (lower temperature) Heat is associated with the movement of particles The faster the particles are moving, the more heat you generate (and vice versa) If the system gives heat to the surroundings, the sign of q is negative. If the surroundings give heat to the system, the sign of q is positive. Chapter

8 The First Law of Thermodynamics In a reaction, energy is conserved. It is neither created nor destroyed. It can be converted into a different type of energy though! The energy change in a system equals the work done on the system + the heat added. Total Energy of Reactants = Total Energy of Products E = E final E initial = q + w Chapter 8 15 Energy and Enthalpy Most chemical reactions are performed in containers that are open to the atmosphere. The volume of the system is allowed to change but the pressure (atmospheric pressure) remains constant. If the work performed is limited to PV work, a state function called Enthalpy (H) can be defined. H = E + PV The change in enthalpy ( H) is equal to the heat absorbed by the system under conditions of constant pressure. H = E + P V Chapter

9 Energy and Enthalpy The following reaction has E = 186 kj/mol. Is the sign of P V positive or negative? What is the sign and approximate magnitude of H? Chapter 8 17 Enthalpy Changes: Physical Change There are two types of Enthalpy changes: The Enthalpy of Physical Change. The Enthalpy of Chemical Change The Enthalpy of Physical Change is the amount of heat required to change the state of matter Chapter

10 Enthalpy Changes: Chemical Change The Enthalpy of Chemical change deals with the energy requirements of chemical reactions. The Heat of the Reaction ( H rxn ) gives the amount of heat absorbed or released due to a chemical reaction at constant pressure. H rxn = H products H reactants If a reaction has more than one step, the H rxn is the sum of the H for each individual reaction. (1) Reactants Elements Heat Absorbed = H 1 (2) Elements Products Heat Absorbed = H 2 (Overall) Reactants Products Heat Absorbed = H rxn Chapter 8 19 Enthalpy Changes: Chemical Change In an Exothermic reaction, the reaction releases energy in the form of heat to the surroundings (you feel the reaction get hot!) The energy of the reactants is greater than that of the products. C (s) + O 2 (g) CO 2 + Energy Reactants Products In an Endothermic reaction, the reaction absorbs energy in the form of heat from the surroundings (you feel the reaction get cold!) The energy of the products is greater than that of the reactants. 2 H 2 O (l) + Energy 2 H 2 (g) + O 2 (g) Chapter

11 Enthalpy Changes: Chemical Change The reaction between hydrogen and oxygen to yield water vapor has H = 484 kj. How much PV work is done, and what is the value of E (in kilojoules) for the reaction of 0.50 mol of H 2 with 0.25 mol of O 2 at atmospheric pressure if the volume change is 5.6 L? The explosion of 2.00 mol of solid TNT with a volume of approximately L produces gases with a volume of 489 L at room temperature. How much PV (in kilojoules) work is done during the explosion? Assume P = 1 atm, T = 25 C. 2 C 7 H 5 N 3 O 6 (s) 12 CO(g) + 5 H 2 (g) + 3 N 2 (g) + 2 C(s) Chapter 8 21 Stoichiometry and Enthalpy Changes How much heat (in kilojoules) is evolved or absorbed in each of the following reactions? State whether the reactions are endothermic or exothermic. Burning of 15.5 g of propane: C 3 H 8 (g) + 5 O 2 (g) 3 CO 2 (g) + 4 H 2 O(l) H = 2219 kj Reaction of 4.88 g of barium hydroxide octahydrate with ammonium chloride: Ba(OH) 2 8 H 2 O(s) + 2 NH 4 Cl(s) BaCl 2 (aq) + 2 NH 3 (aq) + 10 H 2 O(l) H = kj Chapter

12 Standard State To insure a standardization of enthalpy measurements from different experimental sources, a standard set of conditions has been selected. Thermodynamic Standard State: Most stable form of a substance at 1 atm pressure and 25 C 1 M concentration for all substances in solution. Measurements made under these conditions are indicated by a superscript to the symbol of the quantity reported. Standard enthalpy change is indicated by the symbol H. Chapter 8 23 Hess s Law Hess s Law: The overall enthalpy change for a reaction is equal to the sum of the enthalpy changes for the individual steps in the reaction. 3 H 2 (g) + N 2 (g) 2 NH 3 (g) H = 92.2 kj Chapter

13 Hess s Law Reactants and products in individual steps can be added and subtracted to determine the overall equation. (a) 2 H 2 (g) + N 2 (g) N 2 H 4 (g) H 1 =? (b) N 2 H 4 (g) + H 2 (g) 2 NH 3 (g) H 2 = kj (c) 3 H 2 (g) + N 2 (g) 2 NH 3 (g) H 3 = 92.2 kj H 1 = H 3 H 2 = ( 92.2 kj) ( kj) = kj Chapter 8 25 Manipulating Chemical Enthalpy Changes Reversing a reaction changes the sign of H for a reaction: C 3 H 8 (g) + 5 O 2 (g) 3 CO 2 (g) + 4 H 2 O(l) H = 2219 kj 3 CO 2 (g) + 4 H 2 O(l) C 3 H 8 (g) + 5 O 2 (g) H = kj Multiplying a reaction increases H by the same factor because H is also stoichiometrically related to the coefficients of the balanced chemical equation: 3(C 3 H 8 (g) + 5 O 2 (g) 3 CO 2 (g) + 4 H 2 O(l) H = 2219 kj) 3 C 3 H 8 (g) + 15 O 2 (g) 9 CO 2 (g) + 12 H 2 O(l) H = 6657 kj Chapter

14 Hess s Law The industrial degreasing solvent methylene chloride (CH 2 Cl 2, dichloromethane) is prepared from methane by reaction with chlorine: CH 4 (g) + Cl 2 (g) CH 2 Cl 2 (g) + HCl(g) Use the following data to calculate H (in kilojoules) for the above reaction: CH 4 (g) + Cl 2 (g) CH 3 Cl(g) + HCl(g) H = 98.3 kj CH 3 Cl(g) + Cl 2 (g) CH 2 Cl 2 (g) + HCl(g) H = 104 kj Chapter 8 27 Hess s Law What is the equation and H for the net reaction? Which arrow on the diagram corresponds to which step and which arrow corresponds to the net reaction? The diagram shows three energy levels. The energies of which substances are represented by each? Chapter

15 Standard Heats of Formation Where do all of these H values come from that we have been using? Has someone determined these values for all of these reactions? Standard Heats of Formation ( H f ): The enthalpy change for the formation of 1 mole of substance in its standard state from its constituent elements in their standard states. C (s) + 2 H 2 (g) CH 4 (g) H f = kj The standard heat of formation for any element in its standard state is defined as being ZERO. H f = 0 for an element in its standard state Chapter 8 29 Standard Heats of Formation The standard enthalpy change for any chemical reaction is found by subtracting the sum of the heats of formation of all reactants from the sum of the heats of formation of all products H = Σ H f (Products) Σ H f (Reactants) For a balanced equation, each heat of formation must be multiplied by the stoichiometric coefficient. aa + bb cc + dd H = [c H f (C) + d H f (D)] [a H f (A) + b H f (B)] Chapter

16 Standard Heats of Formation Calculate H (in kilojoules) for the reaction of ammonia with O 2 to yield nitric oxide (NO) and H 2 O(g), a step in the Ostwald process for the commercial production of nitric acid. Calculate H (in kilojoules) for the photosynthesis of glucose from CO 2 and liquid water, a reaction carried out by all green plants. Chapter 8 31 Bond Dissociation Energy There are over 18 million chemical compounds known at this time. Who do you think is making all of the H f determinations for those compounds? It is possible to get an approximate H f for a compound based on the bonds present. The Bond Dissociation Energy can be used to determine an approximate value for H f. H f = D (Bonds Broken) D (Bonds Formed) H f = D (Reactant Bonds) D (Product Bonds) Chapter

17 Bond Dissociation Energy To work these problems you will have to draw the Lewis Structures of the reactants and products. Refer to your notes from Chapter 7 For the reaction between H 2 and Cl 2 to form HCl: H 2 (g) + Cl 2 (g) 2 HCl (g) H f = D (Bonds Broken) D (Bonds Formed) H f = (D H-H + D Cl-Cl ) 2(D H Cl ) = (436 kj/mol kj/mol) 2(432 kj/mol) = -185 kj Chapter 8 33 Bond Dissociation Energy Calculate an approximate H (in kilojoules) for the synthesis of ethyl alcohol from ethylene: C 2 H 4 (g) + H 2 O(g) C 2 H 5 OH(g) Calculate an approximate H (in kilojoules) for the synthesis of hydrazine from ammonia: 2 NH 3 (g) + Cl 2 (g) N 2 H 4 (g) + 2 HCl(g) Chapter

18 Calorimetry and Heat Capacity The Bond energies and Heats of Formation give us an approximate idea of H f. How do we experimentally measure the amount of heat transferred during a reaction? Calorimetry is the science of measuring heat changes (q) for chemical reactions. There are two types of calorimeters: Bomb Calorimetry: A bomb calorimeter measures the heat change at constant volume such that q = E. Constant Pressure Calorimetry: A constant pressure calorimeter measures the heat change at constant pressure such that q = H. Chapter 8 35 Calorimetry and Heat Capacity Constant Pressure Bomb Chapter

19 Calorimetry and Heat Capacity Heat capacity (C) is an extensive property that gives the amount of heat required to raise the temperature of an object or substance a given amount. The greater the Heat Capacity, the greater the amount of heat needed to increase the temperature C = q T Units: J/K or J/ C Specific Heat (SH): The amount of heat required to raise the temperature of 1.00 g of substance by 1.00 C. q = SH m T Molar Heat Capacity (C M ): The amount of heat required to raise the temperature of 1.00 mole of substance by 1.00 C. q = C M n T Chapter 8 37 Calorimetry and Heat Capacity What is the specific heat of lead if it takes 96 J to raise the temperature of a 75 g block by 10.0 C? When 25.0 ml of 1.0 M H 2 SO 4 is added to 50.0 ml of 1.0 M NaOH at 25.0 C in a calorimeter, the temperature of the solution increases to 33.9 C. Assume specific heat of solution is J/(g C), and the density is 1.00 g/ml, calculate H for the reaction. Chapter

20 Calorimetry and Heat Capacity A 12.6 g block of Iron has a temperature of 25.3 C. What is the final temperature of the block if J of heat are added? Chapter 8 39 Introduction to Entropy We have stated that chemical and physical processes occur spontaneously only if they go downhill energetically (give off energy) so that the final state is more stable and lower in energy than the initial state. However, we know that reactions that require energy (endothermic reactions) will also occur. This is possible because energy is more than just heat. There are other forms of energy present in reactions that allow it to be spontaneous despite absorbing heat. Another factor that effects spontaneity of a reaction is the molecular disorder of the reaction. The amount of molecular disorder (or randomness) in a system is called the system s Entropy (S) Chapter

21 Entropy Entropy has units of J/K (Joules per Kelvin). S = S final S initial Positive value of S indicates increased disorder. Negative value of S indicates decreased disorder. Second Law of Thermodynamics: Reactions proceed in the direction that increases the entropy of the system plus surroundings. Chapter 8 41 Entropy 2 CO(g) + O 2 (g) 2 CO 2 (g) CaCO 3 (s) CaO (s) + CO 2 (g) 2 C 2 H 6 (g) + 7 O 2 (g) 4 CO 2 (g) + 6 H 2 O(g) Chapter

22 Entropy and Enthalpy To decide whether a process is spontaneous, both enthalpy and entropy changes must be considered: Spontaneous process: Decrease in enthalpy ( H). Increase in entropy (+ S). Nonspontaneous process: Increase in enthalpy (+ H). Decrease in entropy ( S). Chapter 8 43 Introduction to Gibbs Free Energy Gibbs Free Energy Change ( G) weighs the relative contributions of enthalpy and entropy to the overall spontaneity of a process. G = H T S G < 0 G = 0 G > 0 Spontaneous Equilibrium Non-spontaneous Chapter

23 Gibbs Free Energy G = H T S Chapter 8 45 Gibbs Free Energy Which of the following reactions are spontaneous under standard conditions at 25 C? AgNO 3 (aq) + NaCl(aq) AgCl(s) + NaNO 3 (aq) G = 55.7 kj 2 C(s) + 2 H 2 (g) C 2 H 4 (g) G = 68.1 kj N 2 (g) + 3 H 2 (g) 2 NH 3 (g) H = 92 kj; S = 199 J/K Chapter

24 Gibbs Free Energy at Equilibrium Equilibrium ( G = 0): Estimate the temperature at which the following reaction will be at equilibrium. Is the reaction spontaneous at room temperature? N 2 (g) + 3 H 2 (g) 2 NH 3 (g) H = 92.0 kj S = 199 J/K Chapter 8 47 Gibbs Free Energy Benzene, C 6 H 6, has an enthalpy of vaporization, ( H vap ) equal to 30.8 kj/mol and boils at 80.1 C. What is the entropy of vaporization, S vap, for benzene? C 6 H 6 (l) C 6 H 6 (g) H vap = 30.8 kj/mol Chapter

Chapter 8 Thermochemistry: Chemical Energy

Chapter 8 Thermochemistry: Chemical Energy Chapter 8 Thermochemistry: Chemical Energy 國防醫學院生化學科王明芳老師 2011-11-8 & 2011-11-15 Chapter 8/1 Energy and Its Conservation Conservation of Energy Law: Energy cannot be created or destroyed; it can only be

More information

Chapter 6 Thermochemistry

Chapter 6 Thermochemistry Chapter 6 Thermochemistry Thermochemistry Thermochemistry is a part of Thermodynamics dealing with energy changes associated with physical and chemical reactions Why do we care? - Will a reaction proceed

More information

Thermochemistry. Energy. 1st Law of Thermodynamics. Enthalpy / Calorimetry. Enthalpy of Formation

Thermochemistry. Energy. 1st Law of Thermodynamics. Enthalpy / Calorimetry. Enthalpy of Formation THERMOCHEMISTRY Thermochemistry Energy 1st Law of Thermodynamics Enthalpy / Calorimetry Hess' Law Enthalpy of Formation The Nature of Energy Kinetic Energy and Potential Energy Kinetic energy is the energy

More information

Energy and Chemical Change

Energy and Chemical Change Energy and Chemical Change Section 16.1 Energy In your textbook, read about the nature of energy. In the space at the left, write true if the statement is true; if the statement is false, change the italicized

More information

The Nature of Energy. Chapter Six: Kinetic vs. Potential Energy. Energy and Work. Temperature vs. Heat

The Nature of Energy. Chapter Six: Kinetic vs. Potential Energy. Energy and Work. Temperature vs. Heat The Nature of Energy Chapter Six: THERMOCHEMISTRY Thermodynamics is the study of energy and its transformations. Thermochemistry is the study of the relationship between chemical reactions and energy changes

More information

Thermochemistry. Energy and Chemical Change

Thermochemistry. Energy and Chemical Change Thermochemistry Energy and Chemical Change Energy Energy can change for and flow, but it is always conserved. The Nature of Energy Energy the ability to do work or produce heat Potential energy Kinetic

More information

CHEMISTRY. Chapter 5 Thermochemistry

CHEMISTRY. Chapter 5 Thermochemistry CHEMISTRY The Central Science 8 th Edition Chapter 5 Thermochemistry Dr. Kozet YAPSAKLI The Nature of Energy Kinetic and Potential Energy Potential energy can be converted into kinetic energy. E p = mgh

More information

Thermochemistry Chapter 4

Thermochemistry Chapter 4 Thermochemistry Chapter 4 Thermochemistry is the study of energy changes that occur during chemical reactions Focus is on heat and matter transfer between the system and the surroundings Energy The ability

More information

Types of Energy Calorimetry q = mc T Thermochemical Equations Hess s Law Spontaneity, Entropy, Gibb s Free energy

Types of Energy Calorimetry q = mc T Thermochemical Equations Hess s Law Spontaneity, Entropy, Gibb s Free energy Unit 7: Energy Outline Types of Energy Calorimetry q = mc T Thermochemical Equations Hess s Law Spontaneity, Entropy, Gibb s Free energy Energy Energy is the ability to do work or produce heat. The energy

More information

Chapter 15 Energy and Chemical Change

Chapter 15 Energy and Chemical Change Chapter 15 Energy and Chemical Change Chemical reactions usually absorb or release energy. Section 1: Energy Section 2: Heat Section 3: Thermochemical Equations Section 4: Calculating Enthalpy Change Section

More information

Chapter 3. Thermochemistry: Energy Flow and Chemical Change. 5.1 Forms of Energy and Their Interconversion

Chapter 3. Thermochemistry: Energy Flow and Chemical Change. 5.1 Forms of Energy and Their Interconversion Chapter 3 Thermochemistry: Energy Flow and Chemical Change 5.1 Forms of Energy and Their Interconversion 5.2 Enthalpy: Chemical Change at Constant Pressure 5.3 Calorimetry: Measuring the Heat of a Chemical

More information

Thermochemistry. Energy (and Thermochemistry) World of Chemistry Chapter 10. Energy. Energy

Thermochemistry. Energy (and Thermochemistry) World of Chemistry Chapter 10. Energy. Energy Thermochemistry Thermodynamics is the science of the relationship between heat and other forms of energy. (and Thermochemistry) World of Chemistry Chapter 10 is defined as the ability to do work or produce

More information

Chapter 5. Thermochemistry

Chapter 5. Thermochemistry Chapter 5 Thermochemistry Dr. A. Al-Saadi 1 Preview Introduction to thermochemistry: Potential energy and kinetic energy. Chemical energy. Internal energy, work and heat. Exothermic vs. endothermic reactions.

More information

Thermochemistry. Energy and Chemical Change

Thermochemistry. Energy and Chemical Change Thermochemistry Energy and Chemical Change Energy Energy can change for and flow, but it is always conserved. The Nature of Energy Energy the ability to do work or produce heat Potential energy Kinetic

More information

Chapter 8. Thermochemistry 강의개요. 8.1 Principles of Heat Flow. 2) Magnitude of Heat Flow. 1) State Properties. Basic concepts : study of heat flow

Chapter 8. Thermochemistry 강의개요. 8.1 Principles of Heat Flow. 2) Magnitude of Heat Flow. 1) State Properties. Basic concepts : study of heat flow 강의개요 Basic concepts : study of heat flow Chapter 8 Thermochemistry Calorimetry : experimental measurement of the magnitude and direction of heat flow Thermochemical Equations Copyright 2005 연세대학교이학계열일반화학및실험

More information

First Law of Thermodynamics: energy cannot be created or destroyed.

First Law of Thermodynamics: energy cannot be created or destroyed. 1 CHEMICAL THERMODYNAMICS ANSWERS energy = anything that has the capacity to do work work = force acting over a distance Energy (E) = Work = Force x Distance First Law of Thermodynamics: energy cannot

More information

Energy and Chemical Change

Energy and Chemical Change Energy and Chemical Change Section 15.1 Energy In your textbook, read about the nature of energy. In the space at the left, write true if the statement is true; if the statement is false, change the italicized

More information

Ch. 17 Thermochemistry

Ch. 17 Thermochemistry Ch. 17 Thermochemistry 17.1 The Flow of Energy Energy Transformations Thermochemistry: study of energy changes in chemical reactions and changes in state Chemical potential energy: energy stored in bonds

More information

Saturday Study Session 1 3 rd Class Student Handout Thermochemistry

Saturday Study Session 1 3 rd Class Student Handout Thermochemistry Saturday Study Session 1 3 rd Class Student Handout Thermochemistry Multiple Choice Identify the choice that best completes the statement or answers the question. 1. C 2 H 4 (g) + 3 O 2 (g) 2 CO 2 (g)

More information

I. The Nature of Energy A. Energy

I. The Nature of Energy A. Energy I. The Nature of Energy A. Energy is the ability to do work or produce heat. It exists in 2 forms: 1. Potential energy is energy due to the composition or position of an object. 2. Kinetic energy is energy

More information

Chapter 6 Energy and Chemical Change. Brady and Senese 5th Edition

Chapter 6 Energy and Chemical Change. Brady and Senese 5th Edition Chapter 6 Energy and Chemical Change Brady and Senese 5th Edition Index 6.1 An object has energy if it is capable of doing work 6.2 Internal energy is the total energy of an object s molecules 6.3 Heat

More information

Energy and Chemical Change

Energy and Chemical Change Energy and Chemical Change Reviewing Vocabulary Match the definition in Column A with the term in Column B. h e d p c f a r m t j i s l u k n q g o Column A 1. The ability to do work or produce heat 2.

More information

Chapter 5: Thermochemistry. Molecular Kinetic Energy -Translational energy E k, translational = 1/2mv 2 -Rotational energy 5.

Chapter 5: Thermochemistry. Molecular Kinetic Energy -Translational energy E k, translational = 1/2mv 2 -Rotational energy 5. Chapter 5: Thermochemistry 1. Thermodynamics 2. Energy 3. Specific Heat 4. Enthalpy 5. Enthalpies of Reactions 6. Hess s Law 7. State Functions 8. Standard Enthalpies of Formation 9. Determining Enthalpies

More information

Chemistry Chapter 16. Reaction Energy

Chemistry Chapter 16. Reaction Energy Chemistry Reaction Energy Section 16.1.I Thermochemistry Objectives Define temperature and state the units in which it is measured. Define heat and state its units. Perform specific-heat calculations.

More information

Thermochemistry: Energy Flow and Chemical Reactions

Thermochemistry: Energy Flow and Chemical Reactions Thermochemistry: Energy Flow and Chemical Reactions Outline thermodynamics internal energy definition, first law enthalpy definition, energy diagrams, calorimetry, theoretical calculation (heats of formation

More information

Thermodynamics. Thermodynamics of Chemical Reactions. Enthalpy change

Thermodynamics. Thermodynamics of Chemical Reactions. Enthalpy change Thermodynamics 1 st law (Cons of Energy) Deals with changes in energy Energy in chemical systems Total energy of an isolated system is constant Total energy = Potential energy + kinetic energy E p mgh

More information

Thermochemistry. Energy. 1st Law of Thermodynamics. Enthalpy / Calorimetry. Enthalpy of Formation

Thermochemistry. Energy. 1st Law of Thermodynamics. Enthalpy / Calorimetry. Enthalpy of Formation Thermochemistry Energy 1st Law of Thermodynamics Enthalpy / Calorimetry Hess' Law Enthalpy of Formation The Nature of Energy Kinetic Energy and Potential Energy Kinetic energy is the energy of motion:

More information

Lecture Presentation. Chapter 6. Thermochemistry. Sherril Soman Grand Valley State University Pearson Education, Inc.

Lecture Presentation. Chapter 6. Thermochemistry. Sherril Soman Grand Valley State University Pearson Education, Inc. Lecture Presentation Chapter 6 Thermochemistry Sherril Soman Grand Valley State University Chemical Hand Warmers Most hand warmers work by using the heat released from the slow oxidation of iron 4 Fe(s)

More information

Chapter 5 Thermochemistry

Chapter 5 Thermochemistry Chapter 5 Thermochemistry Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Explain how energy, heat, and work are related. 2 Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Classify

More information

10-1 Heat 10-2 Calorimetry 10-3 Enthalpy 10-4 Standard-State Enthalpies 10-5 Bond Enthalpies 10-6 The First Law of Thermodynamics

10-1 Heat 10-2 Calorimetry 10-3 Enthalpy 10-4 Standard-State Enthalpies 10-5 Bond Enthalpies 10-6 The First Law of Thermodynamics Chapter 10 Thermochemistry 10-1 Heat 10-2 Calorimetry 10-3 Enthalpy 10-4 Standard-State Enthalpies 10-5 Bond Enthalpies 10-6 The First Law of Thermodynamics OFB Chap. 10 1 OFB Chap. 10 2 Thermite Reaction

More information

Additional Calculations: 10. How many joules are required to change the temperature of 80.0 g of water from 23.3 C to 38.8 C?

Additional Calculations: 10. How many joules are required to change the temperature of 80.0 g of water from 23.3 C to 38.8 C? Additional Calculations: 10. How many joules are required to change the temperature of 80.0 g of water from 23.3 C to 38.8 C? q = m C T 80 g (4.18 J/gC)(38.8-23.3C) = 5183 J 11. A piece of metal weighing

More information

I PUC CHEMISTRY CHAPTER - 06 Thermodynamics

I PUC CHEMISTRY CHAPTER - 06 Thermodynamics I PUC CHEMISTRY CHAPTER - 06 Thermodynamics One mark questions 1. Define System. 2. Define surroundings. 3. What is an open system? Give one example. 4. What is closed system? Give one example. 5. What

More information

Section 9: Thermodynamics and Energy

Section 9: Thermodynamics and Energy Section 9: Thermodynamics and Energy The following maps the videos in this section to the Texas Essential Knowledge and Skills for Science TAC 112.35(c). 9.01 Law of Conservation of Energy Chemistry (11)(A)

More information

Chapter 5 Thermochemistry

Chapter 5 Thermochemistry Chapter 5 Thermochemistry Learning Outcomes: Interconvert energy units Distinguish between the system and the surroundings in thermodynamics Calculate internal energy from heat and work and state sign

More information

Energy Ability to produce change or do work. First Law of Thermodynamics. Heat (q) Quantity of thermal energy

Energy Ability to produce change or do work. First Law of Thermodynamics. Heat (q) Quantity of thermal energy THERMOCHEMISTRY Thermodynamics Study of energy and its interconversions Energy is TRANSFORMED in a chemical reaction (POTENTIAL to KINETIC) HEAT (energy transfer) is also usually produced or absorbed -SYSTEM:

More information

Chapter 5: Thermochemistry

Chapter 5: Thermochemistry Chapter 5: Thermochemistry 1. Thermodynamics 2. Energy 3. Specific Heat 4. Enthalpy 5. Enthalpies of Reactions 6. Hess s Law 7. State Functions 8. Standard Enthalpies of Formation 9. Determining Enthalpies

More information

Chemistry 101 Chapter 10 Energy

Chemistry 101 Chapter 10 Energy Chemistry 101 Chapter 10 Energy Energy: the ability to do work or produce heat. Kinetic energy (KE): is the energy of motion. Any object that is moving has kinetic energy. Several forms of kinetic energy

More information

Name Date Class THE FLOW OF ENERGY HEAT AND WORK

Name Date Class THE FLOW OF ENERGY HEAT AND WORK 17.1 THE FLOW OF ENERGY HEAT AND WORK Section Review Objectives Explain the relationship between energy, heat, and work Distinguish between exothermic and endothermic processes Distinguish between heat

More information

Thermochemistry: the study of energy (in the from of heat) changes that accompany physical & chemical changes

Thermochemistry: the study of energy (in the from of heat) changes that accompany physical & chemical changes Thermochemistry Thermochemistry: the study of energy (in the from of heat) changes that accompany physical & chemical changes heat flows from high to low (hot cool) endothermic reactions: absorb energy

More information

Ch 6. Energy and Chemical Change. Brady & Senese, 5th Ed.

Ch 6. Energy and Chemical Change. Brady & Senese, 5th Ed. Ch 6. Energy and Chemical Change Brady & Senese, 5th Ed. Energy Is The Ability To Do Work Energy is the ability to do work (move mass over a distance) or transfer heat Types: kinetic and potential kinetic:

More information

Chapter 6 Thermochemistry

Chapter 6 Thermochemistry Chapter 6 Thermochemistry Contents and Concepts Understanding Heats of Reaction The first part of the chapter lays the groundwork for understanding what we mean by heats of reaction. 1. Energy and Its

More information

10-1 Heat 10-2 Calorimetry 10-3 Enthalpy 10-4 Standard-State Enthalpies 10-5 Bond Enthalpies 10-6 The First Law of Thermodynamics

10-1 Heat 10-2 Calorimetry 10-3 Enthalpy 10-4 Standard-State Enthalpies 10-5 Bond Enthalpies 10-6 The First Law of Thermodynamics Chapter 10 Thermochemistry 10-1 Heat 10-2 Calorimetry 10-3 Enthalpy 10-4 Standard-State Enthalpies 10-5 Bond Enthalpies 10-6 The First Law of Thermodynamics OFB Chap. 10 1 Chapter 10 Thermochemistry Heat

More information

Energy Ability to produce change or do work. First Law of Thermodynamics. Heat (q) Quantity of thermal energy

Energy Ability to produce change or do work. First Law of Thermodynamics. Heat (q) Quantity of thermal energy THERMOCHEMISTRY Thermodynamics Study of energy and its interconversions Energy is TRANSFORMED in a chemical reaction (POTENTIAL to KINETIC) HEAT (energy transfer) is also usually produced or absorbed -SYSTEM:

More information

AP* Chemistry THERMOCHEMISTRY

AP* Chemistry THERMOCHEMISTRY AP* Chemistry THERMOCHEMISTRY Terms for you to learn that will make this unit understandable: Energy (E) the ability to do work or produce heat ; the sum of all potential and kinetic energy in a system

More information

10/23/10. Thermodynamics and Kinetics. Chemical Hand Warmers

10/23/10. Thermodynamics and Kinetics. Chemical Hand Warmers 10/23/10 CHAPTER 6 Thermochemistry 6-1 Chemical Hand Warmers Most hand warmers work by using the heat released from the slow oxidation of iron 4 Fe(s) + 3 O2(g) 2 Fe2O3(s) The amount your hand temperature

More information

General Chemistry I. Dr. PHAN TẠI HUÂN Faculty of Food Science and Technology Nong Lam University. Module 4: Chemical Thermodynamics

General Chemistry I. Dr. PHAN TẠI HUÂN Faculty of Food Science and Technology Nong Lam University. Module 4: Chemical Thermodynamics General Chemistry I Dr. PHAN TẠI HUÂN Faculty of Food Science and Technology Nong Lam University Module 4: Chemical Thermodynamics Zeroth Law of Thermodynamics. First Law of Thermodynamics (state quantities:

More information

8.6 The Thermodynamic Standard State

8.6 The Thermodynamic Standard State 8.6 The Thermodynamic Standard State The value of H reported for a reaction depends on the number of moles of reactants...or how much matter is contained in the system C 3 H 8 (g) + 5O 2 (g) > 3CO 2 (g)

More information

THERMOCHEMISTRY & DEFINITIONS

THERMOCHEMISTRY & DEFINITIONS THERMOCHEMISTRY & DEFINITIONS Thermochemistry is the study of the study of relationships between chemistry and energy. All chemical changes and many physical changes involve exchange of energy with the

More information

Thermochemistry. Chapter 6. Dec 19 8:52 AM. Thermochemistry. Energy: The capacity to do work or to produce heat

Thermochemistry. Chapter 6. Dec 19 8:52 AM. Thermochemistry. Energy: The capacity to do work or to produce heat Chapter 6 Dec 19 8:52 AM Intro vocabulary Energy: The capacity to do work or to produce heat Potential Energy: Energy due to position or composition (distance and strength of bonds) Kinetic Energy: Energy

More information

Thermochemistry-Part 1

Thermochemistry-Part 1 Brad Collins Thermochemistry-Part 1 Chapter 7 Thermochemistry Thermodynamics: The study of energy Thermochemistry: The study of energy in chemical reactions Energy: The capacity to do work Work = force

More information

Name Date Class SECTION 16.1 PROPERTIES OF SOLUTIONS

Name Date Class SECTION 16.1 PROPERTIES OF SOLUTIONS SOLUTIONS Practice Problems In your notebook, solve the following problems. SECTION 16.1 PROPERTIES OF SOLUTIONS 1. The solubility of CO 2 in water at 1.22 atm is 0.54 g/l. What is the solubility of carbon

More information

Thermochemistry. Chapter 6. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Thermochemistry. Chapter 6. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thermochemistry Chapter 6 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Energy is the capacity to do work. Radiant energy comes from the sun and is earth s

More information

Chapter 6: Thermochemistry

Chapter 6: Thermochemistry Chem 1045 General Chemistry by Ebbing and Gammon, 8th Edition George W.J. Kenney, Jr Last Update: 24-Oct-2008 Chapter 6: Thermochemistry These Notes are to SUPPLIMENT the Text, They do NOT Replace reading

More information

Chapter Objectives. Chapter 9 Energy and Chemistry. Chapter Objectives. Energy Use and the World Economy. Energy Use and the World Economy

Chapter Objectives. Chapter 9 Energy and Chemistry. Chapter Objectives. Energy Use and the World Economy. Energy Use and the World Economy Chapter Objectives Larry Brown Tom Holme www.cengage.com/chemistry/brown Chapter 9 Energy and Chemistry Explain the economic importance of conversions between different forms of energy and the inevitability

More information

Chapter 5 Principles of Chemical Reactivity: Energy and Chemical Reactions

Chapter 5 Principles of Chemical Reactivity: Energy and Chemical Reactions Chapter 5 Principles of Chemical Reactivity: Energy and Chemical Reactions Jeffrey Mack California State University, Sacramento Energy & Chemistry Questions that need to be addressed: How do we measure

More information

Thermochemistry is the study of the relationships between chemical reactions and energy changes involving heat.

Thermochemistry is the study of the relationships between chemical reactions and energy changes involving heat. CHEM134- F18 Dr. Al- Qaisi Chapter 06: Thermodynamics Thermochemistry is the study of the relationships between chemical reactions and energy changes involving heat. Energy is anything that has the capacity

More information

AP CHEMISTRY NOTES 4-1 THERMOCHEMISTRY: ENTHALPY AND ENTROPY

AP CHEMISTRY NOTES 4-1 THERMOCHEMISTRY: ENTHALPY AND ENTROPY AP CHEMISTRY NOTES 4-1 THERMOCHEMISTRY: ENTHALPY AND ENTROPY Reaction Rate how fast a chemical reaction occurs Collision Theory In order for a chemical reaction to occur, the following conditions must

More information

Energy Transformations

Energy Transformations Thermochemistry Energy Transformations Thermochemistry - concerned with heat changes that occur during chemical reactions Energy - capacity for doing work or supplying heat weightless, odorless, tasteless

More information

Chapter 8. Thermochemistry

Chapter 8. Thermochemistry Chapter 8 Thermochemistry Copyright 2001 by Harcourt, Inc. All rights reserved. Requests for permission to make copies of any part of the work should be mailed to the following address: Permissions Department,

More information

Energy, Heat and Chemical Change

Energy, Heat and Chemical Change Energy, Heat and Chemical Change Chemistry 35 Fall 2000 Thermochemistry A part of Thermodynamics dealing with energy changes associated with physical and chemical reactions Why do we care? -will a reaction

More information

Ch. 14 Notes ENERGY AND CHEMICAL CHANGE NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics.

Ch. 14 Notes ENERGY AND CHEMICAL CHANGE NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. Ch. 14 Notes ENERGY AND CHEMICAL CHANGE NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. I. Energy the capacity to do work or produce heat A. two basic types of

More information

Mr Chiasson Advanced Chemistry 12 / Chemistry 12 1 Unit B: Thermochemical Changes

Mr Chiasson Advanced Chemistry 12 / Chemistry 12 1 Unit B: Thermochemical Changes Mr Chiasson Advanced Chemistry 12 / Chemistry 12 1 Unit B: Thermochemical Changes Students will be expected to: Compare the molar enthalpies of several combustion reactions involving organic compounds.

More information

First Law of Thermodynamics

First Law of Thermodynamics Energy Energy: ability to do work or produce heat. Types of energy 1) Potential energy - energy possessed by objects due to position or arrangement of particles. Forms of potential energy - electrical,

More information

Chapter 5 Thermochemistry. 許富銀 ( Hsu Fu-Yin)

Chapter 5 Thermochemistry. 許富銀 ( Hsu Fu-Yin) Chapter 5 Thermochemistry 許富銀 ( Hsu Fu-Yin) 1 Thermodynamics The study of energy and its transformations is known as thermodynamics The relationships between chemical reactions and energy changes that

More information

Chapter 6 Thermochemistry 許富銀

Chapter 6 Thermochemistry 許富銀 Chapter 6 Thermochemistry 許富銀 6.1 Chemical Hand Warmers Thermochemistry: the study of the relationships between chemistry and energy Hand warmers use the oxidation of iron as the exothermic reaction: Nature

More information

Lecture outline: Chapter 5

Lecture outline: Chapter 5 Lecture outline: Chapter 5 1. The nature of energy Thermochemistryh 2. First law of thermodynamics 3. Enthalpies of reaction 4. Hess law 5. Enthalpies of formation 1 Chemical Reactivity (1) Does a chemical

More information

Chapter 5. Thermochemistry

Chapter 5. Thermochemistry Chapter 5 Thermochemistry Energy Thermodynamics Study of the relationship between heat, work, and other forms of energy Thermochemistry A branch of thermodynamics Focuses on the study of heat given off

More information

Name: General Chemistry Chapter 11 Thermochemistry- Heat and Chemical Change

Name: General Chemistry Chapter 11 Thermochemistry- Heat and Chemical Change Name: General Chemistry Chapter 11 Thermochemistry- Heat and Chemical Change Notepack 1 Section 11.1: The Flow of Energy Heat (Pages 293 299) 1. Define the following terms: a. Thermochemistry b. Energy

More information

Chapter 6. Thermochemistry

Chapter 6. Thermochemistry Chapter 6. Thermochemistry 1 1. Terms to Know: thermodynamics thermochemistry energy kinetic energy potential energy heat heat vs. temperature work work of expanding gases work of expanding gases under

More information

11B, 11E Temperature and heat are related but not identical.

11B, 11E Temperature and heat are related but not identical. Thermochemistry Key Terms thermochemistry heat thermochemical equation calorimeter specific heat molar enthalpy of formation temperature enthalpy change enthalpy of combustion joule enthalpy of reaction

More information

Chapter 17 Thermochemistry

Chapter 17 Thermochemistry Chapter 17 Thermochemistry Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Explain how energy, heat, and work are related. 2 Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Classify

More information

Thermochemistry: Heat and Chemical Change

Thermochemistry: Heat and Chemical Change Thermochemistry: Heat and Chemical Change 1 Heat or Thermal Energy (q) Heat is a form of energy Is heat the same as temperature? Heat flows between two objects at different temperatures. Hot Cold 2 Chemical

More information

Most hand warmers work by using the heat released from the slow oxidation of iron: The amount your hand temperature rises depends on several factors:

Most hand warmers work by using the heat released from the slow oxidation of iron: The amount your hand temperature rises depends on several factors: Lecture Presentation Chapter 6 Thermochemistry Chemical Hand Warmers Most hand warmers work by using the heat released from the slow oxidation of iron: Exothermic reaction 4 Fe(s) + 3 O 2 (g) 2 Fe 2 O

More information

Thermodynamics. Thermodynamically favored reactions ( spontaneous ) Enthalpy Entropy Free energy

Thermodynamics. Thermodynamically favored reactions ( spontaneous ) Enthalpy Entropy Free energy Thermodynamics Thermodynamically favored reactions ( spontaneous ) Enthalpy Entropy Free energy 1 Thermodynamically Favored Processes Water flows downhill. Sugar dissolves in coffee. Heat flows from hot

More information

Name Class Date. As you read Lesson 17.1, use the cause and effect chart below. Complete the chart with the terms system and surroundings.

Name Class Date. As you read Lesson 17.1, use the cause and effect chart below. Complete the chart with the terms system and surroundings. Name Class Date Thermochemistry 17.1 The Flow of Energy As you read Lesson 17.1, use the cause and effect chart below. Complete the chart with the terms system and surroundings. Process Cause Effect endothermic

More information

Enthalpies of Reaction

Enthalpies of Reaction Enthalpies of Reaction Enthalpy is an extensive property Magnitude of H is directly related to the amount of reactant used up in a process. CH 4 (g) + 2O 2 (g) CO 2 (g) + 2H 2 O(l) H = 890 kj 2CH 4 (g)

More information

CP Chapter 17 Thermochemistry

CP Chapter 17 Thermochemistry CP Chapter 17 Thermochemistry Thermochemistry Thermochemistry is the study of energy that occur during chemical reactions and phase changes (changes of state) The Nature of Energy Energy is the ability

More information

Thermodynamics- Chapter 19 Schedule and Notes

Thermodynamics- Chapter 19 Schedule and Notes Thermodynamics- Chapter 19 Schedule and Notes Date Topics Video cast DUE Assignment during class time One Review of thermodynamics ONE and TWO Review of thermo Wksheet Two 19.1-4; state function THREE

More information

Chapter 17: Energy and Kinetics

Chapter 17: Energy and Kinetics Pages 510-547 S K K Chapter 17: Energy and Kinetics Thermochemistry: Causes of change in systems Kinetics: Rate of reaction progress (speed) Heat, Energy, and Temperature changes S J J Heat vs Temperature

More information

Lecture Outline. 5.1 The Nature of Energy. Kinetic Energy and Potential Energy. 1 mv

Lecture Outline. 5.1 The Nature of Energy. Kinetic Energy and Potential Energy. 1 mv Chapter 5. Thermochemistry Common Student Misconceptions Students confuse power and energy. Students confuse heat with temperature. Students fail to note that the first law of thermodynamics is the law

More information

Brown, LeMay Ch 5 AP Chemistry Monta Vista High School

Brown, LeMay Ch 5 AP Chemistry Monta Vista High School Brown, LeMay Ch 5 AP Chemistry Monta Vista High School 1 From Greek therme (heat); study of energy changes in chemical reactions Energy: capacity do work or transfer heat Joules (J), kilo joules (kj) or

More information

Thermodynamics. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Thermodynamics. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thermodynamics Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thermodynamics is the scientific study of the interconversion of heat and other kinds of energy.

More information

CHEM 103 CHEMISTRY I

CHEM 103 CHEMISTRY I CHEM 103 CHEMISTRY I CHAPTER 5 THERMOCHEMISTRY Inst. Dr. Dilek IŞIK TAŞGIN Inter-Curricular Courses Department Çankaya University, Inc. Energy Energy is the ability to do work or transfer heat. Energy

More information

Chapter 6: Thermochemistry

Chapter 6: Thermochemistry Chapter 6: Thermochemistry Section 6.1: Introduction to Thermochemistry Thermochemistry refers to the study of heat flow or heat energy in a chemical reaction. In a study of Thermochemistry the chemical

More information

THE ENERGY OF THE UNIVERSE IS CONSTANT.

THE ENERGY OF THE UNIVERSE IS CONSTANT. Chapter 6 Thermochemistry.notebook Chapter 6: Thermochemistry Jan 29 1:37 PM 6.1 The Nature of Energy Thermodynamics: The study of energy and its interconversions Energy: the capacity to do work or to

More information

Chapter 6. Thermochemistry

Chapter 6. Thermochemistry Chapter 6 Thermochemistry This chapter develops for the student the concepts of thermochemistry. Upon completion of Chapter 6, the student should be able to: 1. Define and explain the following terms:

More information

Ch. 6 Enthalpy Changes

Ch. 6 Enthalpy Changes Ch. 6 Enthalpy Changes Energy: The capacity to do work. In Physics, there are 2 main types of energy Kinetic (energy of motion) = ½ mv 2 Potential (energy of position due to gravity)= mgh In Chemistry,

More information

Unit 15 Energy and Thermochemistry Notes

Unit 15 Energy and Thermochemistry Notes Name Period CRHS Academic Chemistry Unit 15 Energy and Thermochemistry Notes Quiz Date Exam Date Lab Dates Notes, Homework, Exam Reviews and Their KEYS located on CRHS Academic Chemistry Website: https://cincochem.pbworks.com

More information

If neither volume nor pressure of the system changes, w = 0 and ΔE = q = ΔH. The change in internal energy is equal to the change in enthalpy.

If neither volume nor pressure of the system changes, w = 0 and ΔE = q = ΔH. The change in internal energy is equal to the change in enthalpy. 5 Thermochemistry Visualizing Concepts 5.1 The book s potential energy is due to the opposition of gravity by an object of mass m at a distance d above the surface of the earth. Kinetic energy is due to

More information

The Nature of Energy Energy is the ability to do work or produce Heat, q or Q, is ; flows due to temperature differences (always to )

The Nature of Energy Energy is the ability to do work or produce Heat, q or Q, is ; flows due to temperature differences (always to ) CP Chapter 17 Thermochemistry 2014-2015 Thermochemistry Thermochemistry is the study of energy that occur during chemical and physical changes (changes of state) The Nature of Energy Energy is the ability

More information

Name AP CHEM / / Collected AP Exam Essay Answers for Chapter 16

Name AP CHEM / / Collected AP Exam Essay Answers for Chapter 16 Name AP CHEM / / Collected AP Exam Essay Answers for Chapter 16 1980 - #7 (a) State the physical significance of entropy. Entropy (S) is a measure of randomness or disorder in a system. (b) From each of

More information

Thermochemistry: Part of Thermodynamics

Thermochemistry: Part of Thermodynamics Thermochemistry: Part of Thermodynamics Dr. Vickie M. Williamson @vmwilliamson Student Version 1 Chemical Thermodynamics! Thermodynamics: study of the energy changes associated with physical and chemical

More information

Chapter 5 - Thermochemistry

Chapter 5 - Thermochemistry Chapter 5 - Thermochemistry Study of energy changes that accompany chemical rx s. I) Nature of Energy Energy / Capacity to do work Mechanical Work w = F x d Heat energy - energy used to cause the temperature

More information

Lecture Presentation. Chapter 5. Thermochemistry Pearson Education, Inc.

Lecture Presentation. Chapter 5. Thermochemistry Pearson Education, Inc. Lecture Presentation Chapter 5 Energy Energy is the ability to do work or transfer heat. Energy used to cause an object that has mass to move is called work. Energy used to cause the temperature of an

More information

Warm up. 1) What is the conjugate acid of NH 3? 2) What is the conjugate base of HNO 2? 3) If the ph is 9.2, what is the [H 3 O + ], poh, and [OH - ]?

Warm up. 1) What is the conjugate acid of NH 3? 2) What is the conjugate base of HNO 2? 3) If the ph is 9.2, what is the [H 3 O + ], poh, and [OH - ]? Warm up 1) What is the conjugate acid of NH 3? 2) What is the conjugate base of HNO 2? 3) If the ph is 9.2, what is the [H 3 O + ], poh, and [OH - ]? 4) What is the concentration of H 2 SO 4 if 30.1 ml

More information

Thermochemistry Notes

Thermochemistry Notes Name: Thermochemistry Notes I. Thermochemistry deals with the changes in energy that accompany a chemical reaction. Energy is measured in a quantity called enthalpy, represented as H. The change in energy

More information

33. a. Heat is absorbed from the water (it gets colder) as KBr dissolves, so this is an endothermic process.

33. a. Heat is absorbed from the water (it gets colder) as KBr dissolves, so this is an endothermic process. 31. This is an endothermic reaction so heat must be absorbed in order to convert reactants into products. The high temperature environment of internal combustion engines provides the heat. 33. a. Heat

More information

CHAPTER 17 Thermochemistry

CHAPTER 17 Thermochemistry CHAPTER 17 Thermochemistry Thermochemistry The study of the heat changes that occur during chemical reactions and physical changes of state. Chemical Change: new substances created during chemical reaction

More information

CHEM 1105 S10 March 11 & 14, 2014

CHEM 1105 S10 March 11 & 14, 2014 CHEM 1105 S10 March 11 & 14, 2014 Today s topics: Thermochemistry (Chapter 6) Basic definitions Calorimetry Enthalpy Thermochemical equations Calculating heats of reaction Hess s Law Energy and Heat Some

More information

Unit 15 Energy and Thermochemistry Notes

Unit 15 Energy and Thermochemistry Notes Name KEY Period CRHS Academic Chemistry Unit 15 Energy and Thermochemistry Notes Quiz Date Exam Date Lab Dates Notes, Homework, Exam Reviews and Their KEYS located on CRHS Academic Chemistry Website: https://cincochem.pbworks.com

More information