Name _ Chem 114 Exam 3 Total Points = 105
Problem Session _ Dr. A. H. Martin March 23, 2007
Calculations must be shown for credit on ALL problems, and ALL dependent variables, i.e. x's, must be defined. (8)1. Indicate whether aqueous solutions of t
Revised Spring '99
Answers to the Solution Chemistry Supplementary Sheet 1. A solution of sulfuric acid prepared by dissolving 40.0 g of H2SO4 in 60.0 g of H2O has a density of 1.303 g/mL. Calculate: a) the percent H2SO4by weight b) the mole fractio
Name_ A. Key_
Chem 113 Quiz 5A
Dependent variables (x’s) must be defined for full credit.
(1) 1.
Write the dissociation equation and the Ksp expression for silver chromate, Ag2CrO4.
Ag2CrO4 2 Ag1+ + CrO42-
(4) 2.
Dr. A. H. Martin
March 20, 2008
Ksp = [Ag1
Name _A. Key_ Chem 114 Quiz 4A
Dr. A. H. Martin March 13, 2008
Correct dissociation equations must be given and all dependent variables must be defined for full credit on all problems. (2) 1. Indicate whether aqueous solution of the following salts
Name_ Dr. A. H. Martin Chem 114 Quiz 3A February 14, 2008 (All dependent variables x's must be defined for complete credit) (1) 1. Give the Kc expression for the equilibrium UO2(s) + 4 HF(g) UF4(g) + 2 H2O(g).
Kc [UF 4 ][H 2O]2 [HF ]4
solids are no
Name _A. Key_ Chem 114 Quiz 2A (2) 1.
Dr. A. H. Martin January 31, 2008
Indicate the rate of change of all other species in the reaction in terms of the rate if change of O 2 is [O2]/t. 2 NO + O2 2 NO2
[O2 ] t [NO] 2 t [NO2 ] 2 t
(4)2.
How many g
Name _A. Key_ CHEM 114 Quiz 1A (6) 1. Predict the following and justify your prediction, a)
Dr. A. H. Martin January 24, 2008
A compound dissolves in water in such a fashion that the enthalpy of solution, Hsoln, is positive. Would this process be b
Revised Spring, 2000
Kinetics Supplementary Sheet 1. From the following reaction mechanism determine the overall chemical equation and the rate law. 2B -> B2 A + B2 -> AB2 AB2 -> B + C (fast) (slow) (fast)
The overall equation for this reaction is
Homework due 4/2 Indicate whether the entropy change for the following reactions would be positive or negative. Justify your choice. a) N2(g) + 3 H2(g) ->2 NH3(g) Negative - there are 4 molecules of gas in the reactants and only 2 in the products, th
Homework due 3/31 Calculate the pH at which Co(OH)2 will start to precipitate from a solution that is 0.010 M in CoCl2. (Ksp Co(OH)2 = 2.2x10-20) To solve this problem one first needs to calculate the maximum allowable OH 1concentration, before preci
Homework due 3/26 Indicate how you would distinguish between aqueous solutions of each pair of ions below with ONE simple test . Indicate what you would observe if each ion was present. In these problems one wants to run a test that will yield differ
Homework due 3/19 Calculate the molar solubility of Ca3(PO4)2.
(Ksp Ca3(PO4)2 = 2.0X10-29)
The molar solubility is the concentration of the dissolve salt as if it was completely unionized. Since the salt is really 100 % ionized in solution, the mol
Homework due 3/17 Calculate the pH of a solution prepared by mixing 20 mL of 0.20 M NH 3 with 40 mL of 0.10 M HNO3. (Kb for NH3 = 1.8x10-5) This is a typical titration type problem in which the strong acid HNO 3 is being added to the weak base NH3. T
Homework due 3/14 Calculate the pH of 0.20 L of an NH3-NH4NO3 buffer that is 0.40 M in NH4NO3 and 0.50 M in NH3, a) initially, b) after 0.050 mole of HNO 3 have been added, c) after 0.040 moles KOH have been added to a fresh 0.20 L of the buffer. (Kb
Homework due 3/12 Calculate the pH of a solution that is 0.25 M pyridine, C5H5N and 0.75 M in pyridinium bromide, C5H5NHBr. (Kb for C5H5N = 1.7x10-9) This is an example of a solution containing a weak base, C5H5N, and the salt of its conjugate acid C
Homework due 3/10 Calculate the pH of a solution that is 0.50 M in HC2H3O2 and 0.30 M in Ca(C2H3O2)2. Ka for HC2H3O2 = 1.8x10-5 This is a typical common ion problem in which the solution contains a weak acid and it salt. The initial concentration of
Homework due 2/29 Calculate the pH of a 0.25 M NH4NO3 solution. (Kb for NH3 = 1.8x10-5) This is a typical salt hydrolysis problem in which one must determine the pH of a solution of the salt of a strong acid (HNO3) and a weak base (NH3). First the sa
Homework due 2/27 Indicate whether aqueous solutions of the following salts would be acidic, basic, or neutral. For solutions that are not neutral indicate which ion is causing the solution to be acidic or basic LiC2H3O2 - Basic - comes from the stro
Homework due 2/25 A 0.010 M solution of base B is 15% dissociated. Calculate the K b for base B. The base B dissociates according to the equation: B + H2O BH1+ + OH1-
Since the base is 15 % ionized [BH1+] = [OH1-] = 15% x [B]initial = 0.15 x 0. 010
Homework due 2/18 Give the conjugate acid or conjugate base of the following. The conjugate base of: acid HNO3 H2CO3 H2PO41NH41+ The conjugate acid of base ClO31SO42HAsO42C5H5N conjugate base NO31HCO31HPO42NH3 conjugate acid HClO3 HSO41H2AsO41C5H5NH1
Homework due 2/15 Consider the equilibrium 2 A + B 2 C + 2 D for which Hrxn = 75 kJ. Indicate whether the concentration of B will increase, decrease, or remain the same when the following stresses are placed on the system at equilibrium. a) Some D is
Homework due 2/12 A mixture that is 2.0 M in H2, 2.0 M in I2, and 5.0 M in HI is allowed to come to equilibrium at a temperature where Kc = 46. Calculate the concentration of all species present at equilibrium. H2 + I2 2 HI Since none of the initial
Homework due 2/11 Five moles of A and 7 moles of B are placed in a 5 liter container. If at equilibrium, 3 moles of C are present, calculate K c for the equilibrium 3A + B 2 C. In order to determine the value of Kc, the concentration of all species
Homework due 2/4 Give a mechanism for each of the following reactions that is consistent with the rate law given for that reaction. Be sure to indicate the slow and fast steps in your mechanism. a) 2 A + 2 B -> Products Rate = k[A][B]
Since this rea
Homework due 2/1 Consider the reaction 3A + B + 2C -> P for which the following data has been obtained. Trial [A] [B] [C] Initial Rate 1 0.10 0.20 0.10 0.020 2 0.20 0.20 0.10 0.080 3 0.20 0.20 0.20 0.160 4 0.10 0.40 0.10 0.040 Give the following: a)
Homework due 1/30 For the reaction 2 NO + Cl2 -> 2 NOCl the following kinetic data was obtained. Trial 1 2 3 [NO] 0.50 1.00 1.00 [Cl2] 0.50 0.50 1.00 Initial Rate 1.14 4.56 9.12
Calculate the rate law, the order with respect to each reactant and the
Homework due 1/28 For each of the following equations, indicate the rate of change of all of the other species relative to the rate of change of the underlined species. 2 HBr -> H2 + Br2 r2 [H2] [HBr] rate = - = - = - -t t 2 t r2 [H2] [HBr] - = - = -
Homework due 1/25 The antifreeze in a car is a 50% by weight solution of ethylene glycol, C 2H6O2, in water. Calculate the boiling point and freezing point of this solution. (For H2O: Kb = 0.52C/m Kf = 1.86C/m) This is a typical colligative property