Be able to Define/Understand:

Transcription

1 NAME: CLASS PERIOD: REVIEW FOR HONORS CHEMISTRY SEMESTER 2 EXAM: PART 1 Be able to Define/Understand: Know how to: Chapter 8 Chapter 9 Chapter 10 Law of conservation of mass Characteristics of a chemical/physical change 5 types of reactions Exception-free solubility rules mole ratio metric conversions (L to ml, g to kg, etc) limiting reactant/excess reactant, theoretical yield and percent yield enthalpy (H), specific heat (c p), molar heat capacity (C), entropy (S), Gibbs Free Energy (G), system vs surroundings heat vs. temperature intensive vs. extensive properties G = H - TS (Note that T is in Kelvin!) Hess s Law Useful Equations from ch. 10 study guide Exothermic vs Endothermic Identify chemical/physical changes Determine reaction type Complete (create products) and balance a chemical equation Create total and net ionic equations Convert between grams, moles, particles/molecules/ atoms, and volume Calculate limiting reactant/excess reactant Calculate theoretical yield/percent yield Predict whether reaction will occur and create products Calculate any variable from the Useful Equations table Convert temperatures ( C K) Apply rules for working with chemical equations and Hess s Law (addition, sign chances, cancel similar reactant/products, etc.)

2 Chapter 12 Chapter 13 Define each variable in PV=nRT Ideal Gas assumptions Where the ideal gas law breaks down and why STP Diffusion vs effusion Any variable/equation from below: R = atm L K mol R = kpa L K mol P 1 T 1 = P 2 T 2 V) (constant PV=nRT V 1 T 1 = V 2 T 2 (constant P) T K = T c P 1 V 1 = P 2 V 2 (constant T) K.E. = ½ mv 2 1 atm = kpa = 760 torr V 1 = V 2 n 1 n 2 (constant P,T) solution, suspension, solvent, solute, colloid, solubility, miscible, immiscible, dissociation, hydration, saturated solution, unsaturated solution, supersaturated solution, Henry s Law, electrolyte, nonelectrolyte, polar, nonpolar, mixture, homogeneous, heterogeneous, separation techniques Different measurements of concentration (and their units): ppm, molarity, molality Exception-free solubility rules AND how polarity affects solubility Factors that influence solubility based on state of matter (surface area, stirring, temperature, pressure, etc.) Surfactants, detergents, soaps, emulsion, hard water (what they are, how they interact) Colligative properties and the implications for freezing/boiling point Solve for any variable in PV=nRT Solve for any variable in the gas laws Calculate concentrations Compute volume ore molarity of solutions after dilution (V 1M 1 = V 2M 2) Calculate solution stoichiometry problems 2

3 Chapter 15 Acid vs Base: Arrhenius definition vs Bronsted-Lowry Identify three common strong acids (HCl, HNO 3, H 2SO 4) and bases (NaOH, KOH, Ca(OH) 2) by chemical formula Identify common weak acid (CH3COOH) and base (NH3) by chemical formula Typical characteristics of acids and bases Identify conjugate acid-base pairs Amphoteric (and how it relates to water, Kw, and ph calculations) Neutralization reactions (how much of each acid/base is needed) ph scale calculate [H 3 O + ] and [OH - ] calculate ph from either ion concentration solve neutralization problems rank acids/bases for concentration based on K a Review Guide Part 2: Practice Problems Chapter 8 You have aqueous potassium carbonate and aqueous magnesium chloride in different beakers. 8-1) Identify what kind of reaction you will have and predict the products when these two chemicals are mixed. 8-2) Write and balance the formula equation for this reaction. 8-3) Write a total ionic equation for this reaction. 8-4) Write a net ionic equation for this reaction. Chapter 9 Practice: Calcium carbide, CaC 2, reacts with water to form acetylene. CaC 2(s) + 2H 2 O (l) C 2 H 2(g) + Ca(OH) 2(s) 9-1). How many grams of water are needed to react with 485g of calcium carbide? 3

4 9-2). How many grams of CaC 2 could make 23.6g C 2 H 2? Practice: Hydrogen peroxide, H 2 O 2, decomposes to form water and oxygen Create Balanced Equation: 9-3). How many liters of O 2 can be made from 342g H 2 O 2 if the density of O 2 is g/l? Practice: In the reaction shown below, 28g of nitrogen are reacted with 28g of hydrogen: N 2(g) + 3H 2 2NH 3(g) 9-4). Which is the excess reactant, and which is the limiting reactant? 9-5). What is the theoretical yield of ammonia? 9-6). This reaction produces an actual yield of 28g. What is the percent yield? Practice: Predict products and reaction types. Determine whether or not the reaction will occur, create products, and balance the chemical equation for each. 9-7). C 2 H 6 + O 2 9-8). Pb + ZnCl 2 9-9). lead (II) nitrate + sodium carbonate Chapter ) Calculate ΔH when 1.0 mol of nitrogen is heated from 233 K to 475 K. 4

5 10-2) You need 70.2 J to raise the temperature of 34.0g of ammonia, NH 3 (g), from 23.0 C to 24.0 C. Calculate the molar heat capacity of ammonia. 10-3)Using the standard enthalpies of formation, calculate the enthalpy change accompanying the reaction: 4Al(s) + 6H 2 O(l) 2Al 2 O 3 (s) + 6H 2 (g) Is this reaction endothermic or exothermic? 10-4) Given the entropy change for the first two reactions below, calculate the entropy change for the third reaction below. S 8 (s) + 8O 2 (g) 8SO 2 (g) ΔS = 89 J/K 2SO 2 (g) + O 2 (g) 2SO 3 (g) ΔS= -188 J/K S 8 (s) + 12O 2 (g) 8SO 3 (g) ΔS =? 10-5) A reaction has ΔH = 98 kj and ΔS = 292J/K. Investigate the spontaneity of the reaction at room temperature (25 C). Would increasing the temperature have any effect on the spontaneity of the reaction? Chapter ) The vapor pressure of hydrogen peroxide is torr at 97.9 C. What is this pressure in kpa? 12-2) A gas sample has a volume of 124 ml at 9.0 kpa. What will its volume be at 101 kpa? 5

6 12-3) A gas at 65 C occupies 4.22 L. At what Celsius temperature will the volume be 3.87 L, at the same pressure? 12-4) The pressure inside a tire is 39 psi at 20 C. What will the pressure be after the tire is driven at high speed on a hot highway, when the temperature in the tire is 48 C? 12-5) A 4.44 L container holds 15.4 g of oxygen at C. What is the pressure? Chapter ) A saturated solution of PbCO 3 contains g PbCO 3 in g of water. What is this concentration in parts per million? 13-2) If g of NaOH are dissolved in enough water to make a ml solution, what is the molarity of the solution? 13-3) A chemist wants to produce g of barium sulfate by reacting a M BaCl 2 solution with excess H 2 SO 4, as shown in the reaction below. What volume (in ml) of the BaCl 2 solution should be used? BaCl 2 + H 2 SO 4 BaSO 4 + 2HCl 13-4) You have a concentrated solution that is 16.5 M. If you take 13.5 ml of this solution and dilute it to ml, what is the concentration of the resulting solution? 6

7 Chapter ) If the hydronium ion concentration of a solution is 1.63 x 10-8 M, what is the hydroxide ion concentration? 15-2) Stomach acid contains HCl, in a concentration about 0.03 mol/l. What is the ph of stomach acid? 15-3) The ph of a solution is 9.5. Is it acidic or basic? What is the [H 3 O + ]? What is the [OH - ]? 15-4) What volume of M naoh is required to neutralize ml of M H 2 SO 4? 15-5) Place the following acids in order of increasing strength: Valeric acid, K a = 1.5 x 10-5 Glutaric acid, K a = 3.4 x 10-4 Hypobromous acid, K a = 2.5 x 10-9 Acetylsalicylic acid (aspirin), K a = 3.3 x ) Propanoic acid, C 2 H 5 COOH, is a weak acid. Write the expression defining its acidionization constant, K a. 15-7) The hydronium ion concentration in a M solution of formic acid (a weak acid) is M. Calculate K a for formic acid. 7