Lecture Presentation. Chapter 5. Thermochemistry. John D. Bookstaver St. Charles Community College Cottleville, MO
|
|
- Benjamin Sullivan
- 5 years ago
- Views:
Transcription
1 Lecture Presentation Chapter 5 Thermochemistry John D. Bookstaver St. Charles Community College Cottleville, MO
2 Thermochemistry Thermodynamics is the study of energy and its transformations. Thermochemistry is the study of the relationships between chemical reactions and energy changes involving heat. CH 4(g) + 2O 2(g) CO 2(g) + 2H 2 O (g) + energy (heat)
3 Energy Energy is the ability to do work or transfer heat. Work (w) is the energy used to cause an object with mass to move (energy transferred when a force moves an object) w = F d = m g d F is the force, and d is the distance A force is any kind of push or pull exerted on an object.
4 Energy Heat (q) is a process quantity. Energy used to cause the temperature of an object to rise Energy is transferred from a hotter object to colder object.
5 Potential Energy Potential energy (E p or PE) is energy an object possesses by virtue of its position or chemical composition. E p = mgh where m is mass; g is the gravitational constant, 9.8 m/s 2 ; and h is the height of the object relative to some reference height.
6 Kinetic Energy Kinetic energy (E k or KE) is energy an object possesses by virtue of its motion. 1 2 E k = mv 2 where m is mass and v is speed
7 Units of Energy The SI unit of energy is the joule (J). 1J = 1kg A common, non-si unit is the calorie (cal). amount of energy required to raise the temperature of 1 g of water from 14.5 C to 15.5 C. 1 cal = The nutritional Calorie(capital C), Cal = 1,000 cal = 1 kcal Wheaties that provides 100 nutritional Cal really gives 100 kcal or 100,000 cal m s J
8 System and Surroundings System: The material(s) being studied Surroundings: everything else (not being studied) Energy can be transferred back and forth between a system and its surroundings in the forms of work and heat! Types of systems: Open: matter and energy can be exchanged with the surroundings Closed: exchange energy but not matter with the surroundings Isolated: neither energy nor matter can be exchanged with the surroundings Chemistry, The Central Science, 12th Edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy; and Patrick Woodward Pearson Education, Inc.
9 1 st Law of Thermodynamics Conservation of energy: Energy is neither created nor destroyed. the total energy of the universe is a constant; Energy lost by a system is gained by the surroundings and vice versa. To explore this further we need a more precise definition of energy. Internal Energy, E of a system: sum of all the E k and E p of every component of the system. As the numerical value of a system s internal energy is generally not known, we look at the CHANGE in E, E. E = E final E initial
10 Internal Energy Due conservation of energy, we can determine E without knowing the values for E final and E initial. A closer look at E. It has 3 parts: A number Together shows magnitude and change A unit A sign: gives direction What does this mean??? E is positive when E final > E initial : system gains energy from its surroundings, ( E > 0). This is an endergonic process: system ABSORBS energy from the surroundings. E is negative when E final < E initial : system lost energy to its surroundings, ( E < 0). This is an exergonic process: system RELEASED energy from the surroundings.
11 An Example Energy diagram In a chemical rxn: Initial state refers to the reactants Final state refers to the products When H 2 and O 2 (initial state) form H 2 O (final state) at a given temp., the system loses energy to the surrounding, thus E final < E initial. This makes E for the process (rxn) negative.
12 E, Heat and Work A system can exchange energy with its surroundings as heat (q) and work (w). E of a system changes in magnitude as Heat is added or removed from the system Work done on or by the system An analogy: E is like your money in a bank. You can make deposits and withdrawals in the form of heat or work. Deposits increase E : E > 0 (positive) Withdrawals decrease E : E < 0 (negative) To balance your account (the math): E = q + w Your bank statement reads: When heat is added to a system or work is done on the system, E increases!
13 Sign Conventions When heat is added to a system or work is done on the system, E increases! E = q + w An Example: Gases A and B are confined in a closed system (see figure) and react to form a solid product C. As the reaction occurs, the system loses 1150 J of heat to the surroundings. The piston moves downwards as the rxn takes place. As the volume of the gas decreases under constant atm pressure, the surrounding do 480 J of work on the system. Calc E? A (g) + B (g) C (s)
14 Terminology Some terminology to indicate the direction of heat transfer: A reaction in which the system absorbs/ gains heat: ENDOTHERMIC The surroundings will feel cool Examples: Mixing water with ammonium nitrate Mixing water with potassium chloride Melting ice cubes A reaction in which the system releases/loses heat: EXOTHERMIC The surroundings will feel hot Examples: Mixing water and calcium chloride Acid-base reactions Making ice cubes Hand warmers
15 Endothermic and Exothermic Processes When heat is absorbed by the system from the surroundings, the process is endothermic. An endothermic reaction feels cold. N 2(g) + O 2(g) + energy (heat) 2NO (g)
16 Endothermic and Exothermic Processes When heat is released by the system into the surroundings, the process is exothermic. An exothermic reaction feels hot. CH 4(g) + 2O 2(g) CO 2(g) + 2H 2 O (g) + energy (heat)
17 State Functions We cannot determine precisely the value of E but. It does have a fixed value for a given set of conditions. The conditions: temperature and pressure Also, since energy is an extensive property: E of a system is proportional to the total quantity of matter in the system State function: the value of the state function depends only on the present state of the system, not on the path the system took to reach that state.
18 Altitude (d) from the equator: A Trip to the Caribbean! 3862 km or 2400 miles d = 1649 km or 1025 miles 2213 km or 1375 miles Altitude ( d) is a state function: change in altitude is independent of the path taken Distance travelled is not a state function: it varies depending on route taken.
19 Are q and w State Functions? State function: the value of the state function depends only on the present state of the system, not on the path the system took to reach that state. That is: E depends only on E initial and E final. Look at the diagram: E is the same for both (a) and (b) a) Battery shorted out by a wire System loses energy to surroundings as HEAT b) Battery shorted out by a motor (fan) System loses heat to surroundings as Work (to make the fan turn) Heat In both cases q and w are different, hence q and w are not state functions
20 Enthalpy Measures the flow of heat occurring at constant pressure. The system: gas in a container 2 measurable properties: pressure (P) and volume (V). Like E, are P and V state functions? Yes Why? Depend only on current state of the system; independent of path taken to reach that state. Combining all 3 state functions = enthalpy (H) H = E + PV Do you think H is a state function? Yes
21 P-V Work Look at the schematic: Zn + HCl produces H 2 (g). Assume piston has no mass. The system before the rxn is at equilibrium: the piston does not move and the pressure acting on the piston is atm P. P is constant. The rxn occurs: H 2 (g) is produced. The piston rises. Increase in volume The gas is doing work on the surrounding for the piston to rise against P. This is called P-V work: the work involved in the expansion or compression of gases. w = -P V
22 w = -P V Sign Convention P is always positive or zero If volume expands, do you expect V to positive or negative? Why? Positive b/c V final is greater then V initial. The formula is then: w = P V (notice no sign); so why is there one? Now think: in the previous scenario, we said that the gas does work on the surroundings. Does this mean that work was done a) on the system or b) by the system? By the system What s the sign convention for work in this case? Negative! And it must be shown in the formula! So we get: w = -P V The sign means something in the reactions!
23 Change in Enthalpy, H Recall: H = E + PV Also, E = q + w and w = -P V When a change occurs at constant P, we now talk about the change in enthalpy, H. How do we calc H? H = E + P V H = (q + w) w H = q The H is the heat (q p ) gained or lost at constant P. For most rxns: H and E are small because P V is small. What does this mean for reactions: A process is endothermic when H is positive: H > 0 A process is exothermic when H is negative: H < 0
24 Sample Problem - Determining the Sign of H Indicate the sign of the enthalpy change, H, in these processes carried out under atmospheric pressure and indicate whether each process is endothermic or exothermic: (a) An ice cube melts; (b) 1 g of butane (C 4 H 10 ) is combusted in sufficient oxygen to give complete combustion to CO 2 and H 2 O.
25 Enthalpies of Reaction We know: H = E + P V Can we simplify H? H = H final - H initial How does this relate to a chemical reaction: A + B C + D?? H = H products H reactants The H for a rxn is called enthalpy of reaction or heat of reaction: H rxn When specifying a numerical value for H rxn, also give the reaction that occurred! An example: 2 H 2 (g) + O 2 (g) 2 H 2 O (g) H = kj Is the rxn endo- or exothermic?
26 Thermochemical Equations When the coefficients of balanced equations represent the # of mols of products and reactants producing an enthalpy change. when the specific amounts of chemicals involved is not given. 2 H 2 (g) + O 2 (g) 2 H 2 O (g) H = kj Some guidelines: Enthalpy is an extensive property: magnitude of H is proportional to the amount of reactant consumed in the reaction. What is H when 4 mols of H 2 is consumed? If 2 mols H 2 produces kj Then 4 mols H 2 will produce twice as much: kJ What is H when 3 mols of O 2 is consumed? If 1 mol O 2 produces kj then 3 mols O 2 will produce 3x as much: kj If the rxn to form H 2 O was: H 2 (g) + ½ O 2 (g) H 2 O (g), what would H be? H = kj
27 Enthalpy Guidelines H for a reaction is equal in magnitude but opposite in sign to H of the opposite reaction. Forward rxn: 2 H 2 (g) + O 2 (g) 2 H 2 O (g) H = kj Reverse rxn: 2 H 2 O (g ) 2 H 2 (g) + O 2 (g) H = kj We must put the + sign! H for a reaction depends on the states of the reactants and products. 2 H 2 (g) + O 2 (g) 2 H 2 O (g) H = kj rxn 1 2 H 2 (g) + O 2 (g) 2 H 2 O (l) H = kj rxn 2 Note that in rxn 2, the water produced is in the liquid state. The enthalpy change is slightly higher. Why? More heat is available for transfer to the surroundings b/c the enthalpy of H 2 O (g) is greater than that of H 2 O (l). 2 H 2 O (g) 2 H 2 O (l) ; H = H products H reactants = kj ( kJ) = -88 kj
28 Sample Problem - Relating H to Quantities of Reactants and Products How much heat is released when 4.50 g of methane gas is burned in a constant-pressure system? ( H rxn = -890 kj)
29 Solution Analyze Our goal is to use a thermochemical equation to calculate the heat produced when a specific amount of methane gas is combusted. According to Equation 5.18, 890 kj is released by the system when 1 mol CH 4 is burned at constant pressure. Plan Equation 5.18 provides us with a stoichiometric conversion factor: (1mol CH 4 = 890 kj). Thus, we can convert moles of CH 4 to kj of energy. First, however, we must convert grams of CH 4 to moles of CH 4. Thus, the conversion sequence is grams CH 4 (given) moles CH 4 kj (unknown to be found). Solve By adding the atomic weights of C and 4 H, we have 1 mol CH 4 = 16.0 CH 4. We can use the appropriate conversion factors to convert grams of CH 4 to moles of CH 4 to kilojoules: The negative sign indicates that the system released 250 kj into the surroundings. Chemistry, The Central Science, 12th Edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy; and Patrick Woodward 2012 Pearson Education, Inc.
30 Practice Exercise Relating H to Quantities of Reactants and Products Hydrogen peroxide can decompose to water and oxygen by the reaction 2 H 2 O 2 (l) 2 H 2 O(l) + O 2 (g) H = 196 kj Calculate the quantity of heat released when 5.00 g of H 2 O 2 (l) decomposes at constant pressure. Answer: 14.4 kj Chemistry, The Central Science, 12th Edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy; and Patrick Woodward Pearson Education, Inc.
31 Calorimetry The measurement of heat flow Calorimeter: instrument used to measure heat flow. When an object gains heat, it gets hot; temperature changes. This temp change varies from substance to substance and is determined by a substance s heat capacity. What is heat capacity,c? The amount of heat required to raise the temp of an object by 1 K or 1 C. The greater C is, the greater the heat required to produce a rise in temp. Molar heat capacity, C m : heat capacity for 1 mole of a substance. Units: J/mol K Specific heat capacity, C s : heat capacity for 1 g of a substance. Units: J/g K
32 Specific Heat Capacity Recall: specific heat capacity (or simply specific heat) is the amount of energy (heat) required to raise the temperature of 1 g of a substance by 1 K (or 1 C). Units for C s is J/gK Heat = specific heat capacity x mass x change in temp. q = m x C s x T Remember that: H = q so H = m x C s x T
33 Sample Problem - Relating Heat, Temperature Change, and Heat Capacity (a) How much heat is needed to warm 250 g of water (about 1 cup) from 22 C (about room temperature) to 98 C (near its boiling point)? (b) What is the molar heat capacity of water?
34 Practice Exercise (a) Large beds of rocks are used in some solar-heated homes to store heat. Assume that the specific heat of the rocks is 0.82 J/g K. Calculate the quantity of heat absorbed by 50.0 kg of rocks if their temperature increases by 12.0 C. (b) What temperature change would these rocks undergo if they emitted 450 kj of heat? Answer: (a) J, (b) 11 K decrease = 11 C decrease Chemistry, The Central Science, 12th Edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy; and Patrick Woodward 2012 Pearson Education, Inc.
35 Constant-Pressure Calorimetry By carrying out a reaction in aqueous solution in a simple calorimeter one can indirectly measure the heat change for the system by measuring the heat change for the water in the calorimeter. Because the specific heat for water is well known (4.184 J/g-K), we can measure H for the reaction with this equation: q = H = m x C s x T
36 (a) kj/g (b) kj/mol Bomb Calorimetry Constant volume calorimetry Combustion rxns Reactions can be carried out in a sealed bomb. The heat absorbed (or released) by the water is a very good approximation of the enthalpy change for the reaction. Must know total heat capacity of the calorimeter, C cal. q rxn = -C cal x T A g sample of lactic acid (HC 3 H 5 O 3 ) is burned in a calorimeter whose heat capacity is kj/ C. The temperature increases from C to C. calculate the heat of combustion of lactic acid (a) per gram and (b) per mole.
37 Hess Law If a reaction is carried out in a series of steps, H for the overall reaction will be equal to the sum of the enthalpy changes for the individual steps. Because H is a state function, the total enthalpy change depends only on the initial state of the reactants and the final state of the products. We can estimate H using published H values and the properties of enthalpy. We need to find the route for which H is known for every step of a reaction process. For example: CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2 H 2 O (g) H = -802 kj 2 H 2 O (g) 2 H 2 O (l) H = -88 kj + CH 4 (g) + 2 O 2 (g) + 2 H 2 O (g) CO 2 (g) + 2 H 2 O (g) + 2 H 2 O (l) H = -890 kj The overall rxn: cancel substances common on both sides of rxn arrow. CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2 H 2 O (l) H = -890 kj
38 Sample Problem - Using Hess s Law to Calculate H The enthalpy of reaction for the combustion of C to CO 2 is kj/mol C, and the enthalpy for the combustion of CO to CO 2 is kj/mol C: Using these data, calculate the enthalpy for the combustion of C to CO: 3.
39 Practice Exercise Carbon occurs in two forms, graphite and diamond. The enthalpy of the combustion of graphite is kj/mol, and that of diamond is kj/mol: C(graphite) + O 2 (g) CO 2 (g) H = kj C(diamond) + O 2 (g) CO 2 (g) H = kj Calculate H for the conversion of graphite to diamond: C(graphite) C(diamond) H =? Answer: +1.9 kj Chemistry, The Central Science, 12th Edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy; and Patrick Woodward 2012 Pearson Education, Inc.
40 Enthalpies of Formation H f (heat of formation) is the enthalpy change for the reaction in which a compound is made from its constituent elements in their elemental forms. Magnitude of any enthalpy change is dependent on Pressure Temperature State of reactants and products A set of conditions is therefore required to compare enthalpies of different rxns. This is called standard state and is tabulated for us. Standard enthalpy change of a rxn is the enthalpy change when all reactants and products are in their standard states: H Standard enthalpies of formation, H f, are measured under standard conditions 25 C and 1.00 atm pressure.
41 Sample Problem - Equations Associated with Enthalpies of Formation For which of these reactions at 25 C does the enthalpy change represent a standard enthalpy of formation? For each that does not, what changes are needed to make it an equation whose H is an enthalpy of formation? (a) (b) (c)
42 Practice Exercise Write the equation corresponding to the standard enthalpy of formation of liquid carbon tetrachloride (CCl 4 ). Answer: C(graphite) + 2 Cl 2 (g) CCl 4 (l) Chemistry, The Central Science, 12th Edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy; and Patrick Woodward 2012 Pearson Education, Inc.
43 Let s Simplify this H = Σn H f,products Σm H f reactants n and m are the stoichiometric coefficients. C 3 H 8 (g) + 5O 2 (g) 3CO 2 (g) + 4H 2 O(l) H =??? H = [3( kj) + 4( kj)] [1( kj) + 5(0 kj)] = [( kj) + ( kj)] [( kj) + (0 kj)] = ( kj) ( kj) = kj
44 Sample Problem - Calculating an Enthalpy of Reaction from Enthalpies of Formation (a) Calculate the standard enthalpy change for the combustion of 1 mol of benzene, C 6 H 6 (l), to CO 2 (g) and H 2 O(l). (b) Compare the quantity of heat produced by combustion of 1.00 g propane with that produced by 1.00 g benzene. Plan (a) We need to write the balanced equation for the combustion of C 6 H 6.We then look up values in Appendix C or in Table 5.3 and apply Equation 5.31 to calculate the enthalpy change for the reaction. (b) We use the molar mass of C 6 H 6 to change the enthalpy change per mole to that per gram. We similarly use the molar mass of C 3 H 8 and the enthalpy change per mole calculated in the text previously to calculate the enthalpy change per gram of that substance.
45 Practice Exercise Use Table 5.3 to calculate the enthalpy change for the combustion of 1 mol of ethanol: C 2 H 5 OH(l) + 3 O 2 (g) 2 CO 2 (g) + 3 H 2 O(l)
46 Energy in Foods Most of the fuel in the food we eat comes from carbohydrates and fats.
Chapter 5. Thermochemistry
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 5 John D. Bookstaver St. Charles Community College Cottleville, MO 2009, Prentice-Hall,
More informationChapter 5. Thermochemistry
Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 5 John D. Bookstaver St. Charles Community College St. Peters, MO 2006, Prentice Hall,
More informationThe 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 informationLecture 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 informationChapter 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 informationChapter 5. Thermochemistry. Energy. Potential Energy. aa
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 5 John D. Bookstaver St. Charles Community College Cottleville, MO Energy Energy is the
More informationCHEM 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 informationLecture 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 informationLecture 0503 Calorimetry and Hess s Law
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Lecture 0503 Calorimetry and Hess s Law John D. Bookstaver St. Charles Community College Cottleville,
More informations Traditionally, we use the calorie as a unit of energy. The nutritional Calorie, Cal = 1000 cal. Kinetic Energy and Potential Energy
AP Chemistry: Thermochemistry Lecture Outline 5.1 The Nature of Energy Thermodynamics is the study of energy and its transformations. Thermochemistry is the study of the relationships between chemical
More informationChapter 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 informationThermochemistry AP Chemistry Lecture Outline
Thermochemistry AP Chemistry Lecture Outline Name: thermodynamics: the study of energy and its transformations -- thermochemistry: the subdiscipline involving chemical reactions and energy changes Energy
More informationThermochemistry. 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 informationChem 150 Week 7 Handout 1 Thermochemistry (I) Energy used to move an object over some distance.
Chem 150 Week 7 Handout 1 Thermochemistry (I) Define Energy: The capacity to do work or to transfer heat. Work Energy used to move an object over some distance. w = F x d, where w is work, F is the force,
More informationChapter 5 Thermochemistry
Chapter 5 Thermochemistry Energy -Very much a chemistry topic Every chemical change has an accompanying change of. Combustion of fossil fuels The discharging a battery Metabolism of foods If we are to
More informationThermochemistry 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 informationCalorimetry. Chapter 5. Week 2 Unit 1. Calorimetry. Since we cannot know the of the reactants and products, we measure H through, the of.
Chapter 5 Week 2 Unit 1 Calorimetry John D. Bookstaver St. Charles Community College Cottleville, MO Calorimetry Since we cannot know the of the reactants and products, we measure H through, the of. 1
More informationChapter 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 informationCHEMISTRY. 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 informationTHERMOCHEMISTRY & 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 informationChapter 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 informationCh. 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 informationThermochemistry. 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 informationChapter 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 informationGravity is a force which keeps us stuck to the earth. The Electrostatic force attracts electrons to protons in an atom.
Energy Relations in Chemistry: Thermochemistry The Nature of Energy Sugar you eat is "combusted" by your body to produce CO 2 and H 2 O. During this process energy is also released. This energy is used
More informationEnthalpies 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 informationThermochemistry: 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 informationChapter 6: Thermochemistry
Chapter 6: Thermochemistry 1. Light the Furnace: The Nature of Energy and Its Transformations a. Thermochemistry is the study of the relationships between chemistry and energy i. This means that we will
More informationChemistry 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 informationChapter 6 Problems: 9, 19, 24, 25, 26, 27, 31-33, 37, 39, 43, 45, 47, 48, 53, 55, 57, 59, 65, 67, 73, 78-82, 85, 89, 93
Chapter 6 Problems: 9, 19, 24, 25, 26, 27, 31-33, 37, 39, 43, 45, 47, 48, 53, 55, 57, 59, 65, 67, 73, 78-82, 85, 89, 93 Chapter 6 Thermochemistry The study of chemical reactions and the energy changes
More informationThermochemistry 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 information11B, 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 informationThermochemistry. 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 informationChemistry: The Central Science. Chapter 5: Thermochemistry
Chemistry: The Central Science Chapter 5: Thermochemistry Study of energy and its transformations is called thermodynamics Portion of thermodynamics that involves the relationships between chemical and
More informationFirst 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 informationIf 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 informationBrown, 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 informationName Date Class THERMOCHEMISTRY
Name Date Class 17 THERMOCHEMISTRY SECTION 17.1 THE FLOW OF ENERGY HEAT AND WORK (pages 505 510) This section explains the relationship between energy and heat, and distinguishes between heat capacity
More informationSAMPLE EXERCISE 5.1 Describing and Calculating Energy Changes. SAMPLE EXERCISE 5.1 continued
SAMPLE EXERCISE 5.1 Describing and Calculating Energy Changes A bowler lifts a 5.4-kg (12-lb) bowling ball from ground level to a height of 1.6 m (5.2 feet) and then drops the ball back to the ground.
More informationChapter 8 Thermochemistry: Chemical Energy. Chemical Thermodynamics
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
More informationThermodynamics. Internal Energy. Study of energy and its transformations Thermochemistry
Internal Energy 5.1- Thermodynamics Study of energy and its transformations Thermochemistry Study of energy changes that accompany chemical and physical changes. Energy the capacity to do work or transfer
More informationLecture 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 informationSample Exercise 5.1 Describing and Calculating Energy Changes
Sample Exercise 5.1 Describing and Calculating Energy Changes A bowler lifts a 5.4-kg (12-lb) bowling ball from ground level to a height of 1.6 m (5.2 feet) and then drops the ball back to the ground.
More informationSlide 2 / 118. Thermochemistry
Slide 1 / 118 Slide 2 / 118 Thermochemistry Slide 3 / 118 Table of Contents The Nature of Energy State Functions** Click on the topic to go to that section Enthalpy Measuring Enthalpy Changes: Calorimetry
More informationLecture Presentation. Chapter 5. Thermochemistry. James F. Kirby Quinnipiac University Hamden, CT Pearson Education, Inc.
Lecture Presentation Chapter 5 James F. Kirby Quinnipiac University Hamden, CT 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.
More informationName 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 informationChapter 5 THERMO. THERMO chemistry. 5.4 Enthalpy of Reactions 5.5 Calorimetry 5.6 Hess s Law 5.7 Enthalpies of Formation
Chapter 5 THERMO THERMO chemistry 5.4 Enthalpy of Reactions 5.5 Calorimetry 5.6 Hess s Law 5.7 Enthalpies of Formation Chemical Equations 1 st WRITE the Chemical Equation 2 nd BALANCE the Chemical Equation
More informationFirst 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 informationEnergy 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_ + Units of Energy. Energy in Thermochemistry. Thermochemistry. Energy flow between system and surroundings. 100º C heat 50º C
Units of Energy Like we saw with pressure, many different units are used throughout the world for energy. SI unit for energy 1kg m 1J = 2 s 2 Joule (J) calorie (cal) erg (erg) electron volts (ev) British
More informationChapter 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 informationChapter 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 informationGilbert Kirss Foster. Chapter 9. Thermochemistry. Energy Changes in Chemical Reactions
Gilbert Kirss Foster Chapter 9 Thermochemistry Energy Changes in Chemical Reactions Chapter Outline 9.1 Energy as a Reactant or Product 9.2 Transferring Heat and Doing Work 9.3 Enthalpy and Enthalpy Changes
More informationEnergy, 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 informationEnergy 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 informationUnit 7 Thermochemistry Chemistry 020, R. R. Martin
Unit 7 Thermochemistry Chemistry 020, R. R. Martin 1. Thermochemistry Heat is a form of energy - which may take many forms: - Kinetic energy due to motion, ½ mv 2 - Potential energy due to position - Electrical
More informationChapter 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 informationMr 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 informationSelected Questions on Chapter 5 Thermochemistry
Selected Questions on Chapter 5 Thermochemistry Circle the correct answer: 1) At what velocity (m/s) must a 20.0 g object be moving in order to possess a kinetic energy of 1.00 J? A) 1.00 B) 100 10 2 C)
More informationMost 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 informationThermochemistry. Section The flow of energy
Thermochemistry Section 17.1 - The flow of energy What is Energy? Energy is the capacity for doing work or supplying heat Energy does not have mass or volume, and it can only be detected because of its
More informationTHE NATURE OF ENERGY. Thermochemistry 17/01/1436. Chapter 5. Thermochemistry and Thermodynamics. All forms of energy are either: Kinetic Potential
THE NATURE OF ENERGY The concept of matter has always been easy to grasp because matter can be seen and touched. By contrast, although the concept of energy is a familiar one, it is challenging to deal
More informationSection 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 informationCh. 7: Thermochemistry
Thermodynamics and Thermochemistry Thermodynamics concerns itself with energy and its relationship to the large scale bulk properties of a system that are measurable: Volume, Temperature, Pressure, Heat
More informationGeneral 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 informationCh. 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 informationChapter 6. Thermochemistry. Chapter 6. Chapter 6 Thermochemistry. Chapter 6 Thermochemistry Matter vs Energy 2/16/2016
Chapter 6 Thermochemistry Chapter 6 Chapter 6 Thermochemistry 6.1 Chemical Hand Warmers 6.2 The Nature of Energy: Key Definitions 6.3 The First Law of Thermodynamics: There is no Free Lunch 6.4 6.5 Measuring
More informationThermochemistry. 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 informationDecreasing potential energy, increasing kinetic energy
section 5.1 Energy 167 Go Figure Suppose the bicyclist is coasting (not pedaling) at constant speed on a flat road and begins to go up a hill. If she does not start pedaling, what happens to her speed?
More informationChapter 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 informationChapter 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 informationChapter 5: Thermochemistry. Problems: , , 5.100, 5.106, 5.108, , 5.121, 5.126
Chapter 5: Thermochemistry Problems: 5.1-5.95, 5.97-98, 5.100, 5.106, 5.108, 5.118-5.119, 5.121, 5.126 Energy: Basic Concepts and Definitions energy: capacity to do work or to produce heat thermodynamics:
More informationName 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 informationI. 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 informationThermochemistry Ch. 8
Definitions I. Energy (E): capacity to do work. II. Heat (q): transfer of energy from a body at a high temp. to a body at a low temp. III. Reaction perspectives: A. System: the focus. B. Surroundings:
More informationAccelerated Chemistry Study Guide Chapter 12, sections 1 and 2: Heat in Chemical Reactions
Accelerated Chemistry Study Guide Chapter 12, sections 1 and 2: Heat in Chemical Reactions Terms, definitions, topics Joule, calorie (Re-read p 57-58) Thermochemistry Exothermic reaction Endothermic reaction
More informationCHEM 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 informationEnthalpy Chapter 5.3-4,7
Enthalpy Chapter 5.3-4,7 heat transfer in (endothermic), +q heat transfer out (exothermic), -q SYSTEM E = q + w w transfer in (+w) w transfer out (-w) Internal Energy at Constant Volume E = E K + E P ΔE
More informationChapter 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 informationCHAPTER 3 THE FIRST LAW OF THERMODYNAM- ICS
CHAPTER 3 THE FIRST LAW OF THERMODYNAM- ICS Introduction In this chapter, we discuss the First Law of Thermodynamics (energy cannot be created or destroyed). In our discussion, we will define some important
More informationThermochemistry 14.notebook. November 24, Thermochemistry. Energy the capacity to do work or produce heat. translational.
Thermochemistry Energy the capacity to do work or produce heat POTENTIAL ENERGY KINETIC ENERGY (energy of motion) "stored" bond energy TEMPERATURE and HEAT vibrational rotational translational a measure
More informationAP CHEMISTRY. Unit 5 Thermochemistry. Jeff Venables Northwestern High School
AP CHEMISTRY Unit 5 Thermochemistry Jeff Venables Northwestern High School Kinetic Energy and Potential Energy Kinetic energy - the energy of motion: Ek = 1 mv 2 Potential energy - the energy an object
More informationChemistry 123: Physical and Organic Chemistry Topic 2: Thermochemistry
Topic 2: Introduction, Topic 2: Thermochemistry Text: Chapter 7 and 19 (~ 3 weeks) 2.0 Introduction, terminology and scope 2.1 Enthalapy and Energy Change in a chemical process; 1st law of Thermodynamics
More informationCHAPTER 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 informationCh 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 informationThe 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 informationChapter 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 informationEnergy 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 informationENTHALPY, INTERNAL ENERGY, AND CHEMICAL REACTIONS: AN OUTLINE FOR CHEM 101A
ENTHALPY, INTERNAL ENERGY, AND CHEMICAL REACTIONS: AN OUTLINE FOR CHEM 101A PART 1: KEY TERMS AND SYMBOLS IN THERMOCHEMISTRY System and surroundings When we talk about any kind of change, such as a chemical
More informationChapter 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 informationCP 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 information1 of 5. Last time: we finished: titration, dilutions Questions on the test? Today: Energy and chemistry: Thermochemistry
1 of 5 Notes for chem 101 lecture 7b 0) admin Test 2 is on Feb 24 (Wed). 2 Furloughs are coming up: Fri Feb 19 and Mon Feb 22. The test will be on chapters 4-5. (stoichiometry). Review session will be
More informationThermochemistry: 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 informationChapter 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 informationEnergy & Chemistry. Internal Energy (E) Energy and Chemistry. Potential Energy. Kinetic Energy. Energy and Chemical Reactions: Thermochemistry or
Page III-5-1 / Chapter Five Lecture Notes Energy & Chemistry Energy and Chemical Reactions: Thermochemistry or Thermodynamics Chapter Five Burning peanuts supplies sufficient energy to boil a cup of water
More informationChapter 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 informationThermochemistry: 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 informationEnergy 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 informationChapter 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 informationChapter 6. Heat Flow
Chapter 6 Thermochemistry Heat Flow Heat (q): energy transferred from body at high T to body at low T Two definitions: System: part of universe we are interested in Surrounding: the rest of the universe
More information