Chem 122 Exam 2

Write the chemical equation and the Kb expression for the reaction of each of the following bases with water: (a)dimethylamine, (CH3)2 NH; (b) carbonate ion, CO3 2- (c) formate ion, CHO2- (a) (CH3)2 NH + H2O <-----> (CH3)2 NH2+ + OH- ; Kb= [ (CH3)2 NH2+ ] [OH- ]/ [(CH3)2 NH ] (b) CO3 2- + H20 <----------> HCO3 - + OH- ; Kb= [ CO3 2-]/[HCO3-][OH-] (c) CHO2- + H2O <----> HCOOH + OH- ; Kb= [ HCOOH][ OH- ] / [ CHO2- ] (a) (CH3)2 NH + H2O <-----> (CH3)2 NH2+ + OH- ; Kb= [ (CH3)2 NH2+ ] [OH- ]/ [(CH3)2 NH ] (b) CO3 2- + H20 <----------> HCO3 - + OH- ; Kb= [HCO3-][OH-]/ [ CO3 2-] (c) CHO2- + H2O <----> COO2- + H3O+ ; (a) (CH3)2 NH + H2O <-----> (CH3)2 NH2+ + OH- ; Kb= [ (CH3)2 NH2+ ] [OH- ]/ [(CH3)2 NH ] (b) CO3 2- + H20 <----------> HCO3 - + OH- ; Kb= [HCO3-][OH-]/ [ CO3 2-] (c) CHO2- + H2O <----> HCOOH + OH- ; Kb= [ HCOOH][ OH- ] / [ CHO2- ] (a) (CH3)2 NH + H2O <-----> (CH3)2 NH2+ + OH- ; Kb= [(CH3)2NH ]/ [ (CH3)2 NH2+ ] [OH- ] (b) CO3 2- + H20 <----------> HCO3 - + OH- ; Kb= [HCO3-][OH-]/ [ CO3 2-] (c) CHO2- + H2O <----> HCOOH + OH- ; Kb= [ HCOOH][ OH- ] / [ CHO2- ]

(a) (CH3)2 NH + H2O <-----> (CH3)2 NH2+ + OH- ; Kb= [ (CH3)2 NH2+ ] [OH- ]/ [(CH3)2 NH ] (b) CO3 2- + H20 <----------> HCO3 - + OH- ; Kb= [HCO3-][OH-]/ [ CO3 2-] (c) CHO2- + H2O <----> HCOOH + OH- ; Kb= [ HCOOH][ OH- ] / [ CHO2- ]

Predict the products of the following acid-base reactions, and predict whether the equilibrium lies to the left or to the right of the reaction arrow: (a) O2-(aq) + H2O(1)<---> (b) CH3COOH(aq) + HS-(aq)<---> (c) NO2-(aq) + H2O(1)<---> (a) 2 OH-; 100% to products (b) CH3COO- + H2S; towards products (c) HNO2 + OH-; towards reactants (a) 2 OH-; 100% to products (b) CH3COO- + H2S; 100% to products (c) HNO2 + OH-; towards reactants (a) 2 OH-; 100% to products (b) CH3COO- + H2S; towards products (c) HNO2 + OH-; towards products (a) 2 OH-; towards reactants (b) CH3COO- + H2S; towards products (c) HNO2 + OH-; towards reactants

(a) 2 OH-; 100% to products (b) CH3COO- + H2S; towards products (c) HNO2 + OH-; towards reactants

Phenol, C6H5OH, has a Ka = 1.3x 10 -10 (a) Write out the Ka reaction for phenol (b) Calculate Kb for phenols conjugate base (c) Is phenol a stronger or weaker acid than water? (a) C6H5OH + H20 <----> H30+ + C6H5O- (b) Kb= 7.7 x 10-5 (c) Phenol is a stronger acid than water. (a) C6H5OH + H20 <----> 0H- + C6H5OH2+ (b) Kb= 7.7 x 10-5 (c) Phenol is a stronger acid than water. (a) C6H5OH + H20 <----> H30+ + C6H5O- (b) Kb= 7.7 x 10-5 (c) Phenol is a weaker acid than water.

(a) C6H5OH + H20 <----> H30+ + C6H5O- (b) Kb= 7.7 x 10-5 (c) Phenol is a stronger acid than water.

Lable each of the following as beginning a strong base, a weak base, or a special with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (a) CH3COO- (b) HCO3- (c) O2- (d) Cl- (e)NH3+ (a) CH3COO-,WB ; CH3COOH, WA (b) HCO3- , WB ; H2CO3, WA (c) O2- , SB ; OH- , SB (d) Cl- , WB; HCl, SA (e)NH3, WB ; NH4+ , WA WB = Weak base WA= weak acid SB= Strong base SA= strong acid (a) CH3COO-,WB ; CH3COOH, WA (b) HCO3- , WB ; H2CO3, WA (c) O2- , SB ; OH- , SA (d) Cl- , Not a Base at all; HCl, SA (e)NH3, WB ; NH4+ , WA WB = Weak base WA= weak acid SB= Strong base SA= strong acid (a) CH3COO-,WB ; CH3COOH, WA (b) HCO3- , WB ; H2CO3, WA (c) O2- , SB ; OH- , SB (d) Cl- , Not a Base at all; HCl, SA (e)NH3, WB ; NH4+ , WA WB = Weak base WA= weak acid SB= Strong base SA= strong acid (a) CH3COO-,WB ; CH3COOH, WA (b) HCO3- , WB ; H2CO3, WA (c) O2- , SB ; H2O , WB (d) Cl- , Not a Base at all; HCl, SA (e)NH3, WB ; NH4+ , WA WB = Weak base WA= weak acid SB= Strong base SA= strong acid

(a) CH3COO-,WB ; CH3COOH, WA (b) HCO3- , WB ; H2CO3, WA (c) O2- , SB ; OH- , SB (d) Cl- , Not a Base at all; HCl, SA (e)NH3, WB ; NH4+ , WA WB = Weak base WA= weak acid SB= Strong base SA= strong acid

Write the chemical equation and the Ka expression for the ionization of each of the following acids in each aqueous solution. First show the reaction with H+(aq) as a product and then with the hydronium ion: (a) HBrO2 (b) C2H5COOH (a) HBrO2 <-----> H+ + BrO2- ; Ka= [H+][BrO2]/ [HBrO2] HBrO2 +H2O <-----> H3O+ + BrO2- ; Ka= [H3O+] [BrO2-] / [HBrO2] (b) C2H5COOH <-----> H+ + C2H5COO- ; Ka= [H+ ] [C2H5COO-] / [C2H5COOH ] C2H5COOH +H2O <-----> H3O+ + C2H5COO-; Ka = [H3O+] [ C2H5COO-] / [C2H5COOH] (a) HBrO2 <-----> H+ + BrO2- ; Ka= [HBrO2]/[H+][BrO2] HBrO2 +H2O <-----> H3O+ + BrO2- ; Ka= [HBrO2]/[H3O+] [BrO2-] (b) C2H5COOH <-----> H+ + C2H5COO- ; Ka= [C2H5COOH ]/[H+ ] [C2H5COO-] C2H5COOH +H2O <-----> H3O+ + C2H5COO-; Ka = [C2H5COOH]/ [H3O+] [ C2H5COO-]

(a) HBrO2 <-----> H+ + BrO2- ; Ka= [H+][BrO2]/ [HBrO2] HBrO2 +H2O <-----> H3O+ + BrO2- ; Ka= [H3O+] [BrO2-] / [HBrO2] (b) C2H5COOH <-----> H+ + C2H5COO- ; Ka= [H+ ] [C2H5COO-] / [C2H5COOH ] C2H5COOH +H2O <-----> H3O+ + C2H5COO-; Ka = [H3O+] [ C2H5COO-] / [C2H5COOH]

(a) Given that Ka for acetic acid is 1.8 x 10-5 and that hypochlorous acid is 3.0 x10-8 , which is a stronger acid? (b) Which is the stronger base, the acetate ion or the hypochlorite ion? (c) calculate the Kb values for the CHCOO- and ClO- . (a) acetic acid is stronger (b) Acetate ion is stronger (c) CH3COO-, Kb = 3.3 x 10-7 for ClO-, Kb = 5.6 x 10-10 (a) acetic acid is stronger (b) Hypochlorite ion is stronger (c) CH3COO-, Kb = 5.6 x 10-10 for ClO-, Kb = 3.3 x 10-7 (a) Hypochlorous acid is stronger (b) Acetate ion is stronger (c) CH3COO-, Kb = 5.6 x 10-10 for ClO-, Kb = 3.3 x 10-7 (a) Hypochlorous acid is stronger (b) Hypochlorite ion is stronger (c) CH3COO-, Kb = 5.6 x 10-10 for ClO-, Kb = 3.3 x 10-7

(a) acetic acid is stronger (b) Hypochlorite ion is stronger (c) CH3COO-, Kb = 5.6 x 10-10 for ClO-, Kb = 3.3 x 10-7

Indicate whether each statement is true or false. (a) if you compare two reactions with similar collision factors, the one with the larger activation energy will be faster. (b) a reaction that has a small rate constant must have a small frequency factor. (c) Increasing the reaction temperature increases the fraction of successful collisions between reactants. (a) false (b) false (c) true (a) true (b) true (c) true (a) false (b) true (c) true (a) true (b) false (c) true

(a) false (b) false (c) true

(a) The gas-phase decomposition of SO2Cl2 , SO2Cl2(g)---> SO2(g) + Cl2(g), is first order with respect to SO2Cl2 . At 600 K the half- life for this process is 2.3 x 105s. What is the rate of the constant at this temperature? (b) What will be the half life after the sample has decayed from 1 ----> 1/2 ---> 1/4 -------> 1/8 (a) k= 3.3 x 10+5s (b) the same (a) k= 3.0 x 10-6s-1 (b) each successive half life gets longer (a) k= 3.0 x 10-6s-1 (b) each successive half life gets shorter (a) k= 3.0 x 10-6s-1 (b) the same

(a) k= 3.0 x 10-6s-1 (b) the same

Calculate the pH of each of the following solutions (Ka and Kbvalues are given in Appendix D) : (a) 0.095 M propionic acid (C2H5COOH) (b) 0.100 M hydrogen chromate ion (HCrO4-) (c) 0.120 M pyridine (C5H5N) (a) pH=2.95 (b) pH=3.76 (c) pH= 4.85 (a) pH=2.95 (b) pH=3.76 (c) pH= 9.51 (a) pH=2.95 (b) pH=3.76 (c) pH= 9.15 (a) pH=3.95 (b) pH=2.76 (c) pH= 9.15

(a) pH=2.95 (b) pH=3.76 (c) pH= 9.15

The decomposition reaction on N2O5 in carbon tetrachloride is 2 N2 O5-----> 4NO2 + O2. The rate law is first order in N2O5. At 64 °C the rate constant is 4.82 X 10-3s-1 (a) write the rate law for the reaction. (b) what is the rate when the concentration of N2O5 is doubled from 0.0240 M to 0.0480 M? (a) rate= k[N2O5] (b) the rate doubles to 2.32 x 10E(-4) M/sec (a) rate= k[N2O5] (b) the rate is halved to 5.8 x 10E(-5) M/sec (a) rate= k[N2O5] (b) the rate doubles to 1.16 x 10E(-4) M/sec (a) rate= k[N2O5]0 (b) the rate stays the same

(a) rate= k[N2O5] (b) the rate doubles to 2.32 x 10E(-4) M/sec

Calculate [H+] for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral: (a) [OH-]= 0.00045 M; (b) [OH-]= 8.8 X 10-9 M; (c) a solution in which [OH-] is 100 times greater than [H+]. (a)[H+]= 2.2 x 10-11M, basic (b) [H+] = 1.1 x 10-6 M, basic (c) [H+]= 1.0 x 10-8 M, basic (a)[H+]= 2.2 x 10-11M, basic (b) [H+] = 1.1 x 10-6 M, acidic (c) [H+]= 1.0 x 10-8 M, basic (a)[H+]= 2.2 x 10-11M, acidic (b) [H+] = 1.1 x 10-6 M, basicic (c) [H+]= 1.0 x 10-8 M, acidic (a)[H+]= 2.2 x 10-11M, basic (b) [H+] = 1.1 x 10-6 M, acidic (c) [H+]= 1.0 x 10-4 M, acidic

(a)[H+]= 2.2 x 10-11M, basic (b) [H+] = 1.1 x 10-6 M, acidic (c) [H+]= 1.0 x 10-8 M, basic

Give the conjugate base of the following Brosted- Lowry acid: ( i ) HIO3 ( ii ) NH4+ (i) IO3- (ii) NH3 (i) IO3- (ii) NH4+ (i) H2IO3 (ii) NH2-

(i) IO3- (ii) NH3

Give the conjugate acid of the following Bronsted-Lowry bases: ( i ) O2- ( ii ) H2PO4- (i)OH- (ii) HPO42- (i)OH- (ii) PO43- (i) H2O (ii) H3PO4 i)OH- (ii) H3PO4

(i)OH- (ii) H3PO4

If a neutral solution of a water , with pH= 7.00, is cooled to 10oC, the pH rises to 7.27. Which of the following three statements is correct for the cooled water: (i) [H+]>[OH-] (ii) [H+] = [OH-] (iii) [H+] < [OH-] (ii) is correct; the new Kw value at the new temperature is 2.88 x 10-15 (i) is correct (iii) is correct

(ii) is correct; the new Kw value at the new temperature is 2.88 x 10-15

For the following gas-phase reaction, indicate mathematically how the rate of disappearance of each reactant is related to the rate of appearance of each product: 2N2O(g) ---> 2N2(g) + O2(g) - 1/2 Δ [N2O]/ Δt = 1/2 Δ[N2]/Δt = Δ[O2]/Δt - Δ [N2O]/ Δt = Δ[N2]/Δt = Δ[O2]/Δt 1/2 Δ [N2O]/ Δt = - 1/2 Δ[N2]/Δt = - Δ[O2]/Δt

- 1/2 Δ [N2O]/ Δt = 1/2 Δ[N2]/Δt = Δ[O2]/Δt

For the following gas-phase reaction, indicate mathematically how the rate of disappearance of each reactant is related to the rate of appearance of each product: N2(g) + 3H2(g)---> 2NH3(g) -Δ[N2]/Δt=-1/3Δ[H2]/Δt=+1/2Δ[NH3]/Δt -Δ[N2]/Δt =-Δ[H2]/Δt = +Δ[NH3]/Δt -Δ[N2]/Δt=+1/3Δ[H2]/Δt=+1/2Δ[NH3]/Δt Δ[N2]/Δt=-1/3Δ[H2]/Δt=-1/2Δ[NH3]/Δt

-Δ[N2]/Δt=-1/3Δ[H2]/Δt=+1/2Δ[NH3]/Δt

A reaction, A + B ---> C obeys the following rate law: Rate= k[B]2. What are the orders of the reaction with respect to A and B? and what is the overall reaction order? All three listed in that order A, B & overall 1, 2 & 3 0, 2 & 2 1, 2 & 2 0, 2 & 0

0, 2 & 2

If Kc = 1.3 x 10-4 for 2 NO + Cl2 -----> 2 NOCl. What is Kc for 4 NO + 2 Cl2 -------> 4 NOCl? 0.0000000169 7692 13000

0.0000000169

At 2000°C, the equilibrium constant for the reaction 2NO(g) <---> N2(g) + O2(g) is Kc =2.4 x 103. If the initial concentration of NO is 0.175 M, what is the equilibrium concentration of NO? 0.0036 M 0.17 M 0.087 M 0.0018 M

0.0018 M

If Kc = 1.3 x 10-4 for 2 NO + Cl2 -----> 2 NOCl. What is Kc for NO + 1/2 Cl2 -----> NOCl 7692 0.011 13000

0.011

A particular sample of vinegar has a pH of 2.90. If acetic acid is the only acid that vinegar contains. (Ka= 1.8 X 10-5), calculate the concentration of acetic acid in the vinegar. 0.0013 M 0.98 M 0.089 M 11 M

0.089 M

The following equilibria were attained at 823 K: CoO(s) + H2 (g) <---> Co(s) + H2O(g) ; Kc= 67 CoO(s) + CO (g) <---> Co(s) + CO2(g) ; Kc= 490 based on these equilibria, calculate the equilibrium constant for : H2(g) + CO2 <---> CO(g) + H2O(g) at 823K 7.31 67.002 0.137 32,830

0.137

For the following reaction at 2000 degrees C what is the equilibrium partial pressure of IBr if the initial partial pressure of IBr is 0.25 atm and there are no products present initially? 2 IBr -----> I2 + Br2 Kp = 8.5 x 10-3 0.023 0.211 0.0195

0.211

Methane, CH4 reacts with I2 according to the rection CH4(g) + I2(g) <---> CH3I + HI (g). At 630 K, Kp for this reaction is 2.26 x10 -4. A reaction was set up at 630 K with the initial partial pressure of methane of 105.1 torrs and of 7.96 torrs for I2. Calculate the partial pressures, in torr, of the products at equilibrium. Hints: Kp is in terms of atm.s and not torr. You must convert twice. Do the algebra here and solve using the quadratic equation. 7.56 torr 0.422 torr 104.5 torr 5.56 x 10E(-4) torr

0.422 torr

A reaction, 2A + 3B ------> 2 C, obeys the rate law: r = k[A][B]2. What is the order of this reaction with respect to A? 0 1 2 3

1

If a 0.10 M solution of an unknown monoprotic weak acid has a pH of 3.50, what is Ka for this acid? 3.2 x 10E(-3) 1.0 x 10E(-6) 1.0 x 10E(-7) 3.2 x 10E(-4)

1.0 x 10E(-6)

Radioactive decay is a classic first order process. The half-life of 14C is 5,730 yr's. What is the rate constant, k, for this first order reaction? 5,730 yr's 1.75 x 10-4 yr-1 1.21 x 10-4 yr-1 5.25 x 10-5 yr-1

1.21 x 10-4 yr-1

Methanol is produced commercially by the catalyzed reaction of carbon monoxide and hydrogen: CO(g) + 2 H2 <---> CH3OH (g). An equilibrium mixture in a 2.00-L vessel is found to contain 0.0406 mol CH3OH, 0.170 mol CO and 0.302 mol H2 at 500 K. Calculate Kc at this temperature. 1.58 10.5 0.633 9.52 x 10E(-2)

10.5

What is the pH of a solution where potassium oxide concentration is 1 x 10-3M? 11.00 11.30 2.70 3.00

11.30

A reaction, 2A + 3B ------> 2 C, obeys the rate law: r = k[A][B]2. What is the order of this reaction with respect to B? 2 0 3 1

2

Consider the potential energy vs reaction coordinate diagram in problem 70 in your text on pg 616. How many steps does this mechanism have? 3 0 1 2

2

Based on the reaction profile illustrated in problem #69 on page 616, a) how many intermediates are formed in the reaction A---> D? (b) how many transition states are there? (c) which step is the fastest? (d) for the reactions A---> D, is the delta E positive, negative, or zero? Answers listed as a), b), c) & d) 2, 3, third step, - 3, 2, third step, + 2, 3, second step, + 2, 3, third step, +

2, 3, third step, +

What is the pH of a solution where hydrochloric acid concentration is 1 x 10-2M? 2.00 1 x 10E(-2) 12.00 -2.00

2.00

If a 0.50 M solution of an unknown monoprotic weak acid has a pH of 2.44, what is Ka for this acid? 3.6 x 10E(-3) 7.3 x 10E(-3) 2.7x10E(-5) 138

2.7x10E(-5)

The following data were measured for the reaction 2 NO(g) + Br2(g) ---> 2 NOBr(g) Experiment[NO] (M)[Br2] (M) initial rate (M/s)10.100.202420.250.2015030.100.506040.350.50735 what is the overall order the reaction? 3 0 2 4

3

What is the pH of a solution where hydronium ion concentration is 1 x 10-3M? 3.00 -3.00 1 x 10E(-3) 11.00

3.000

Calculate the concentration of an aqueous solution of NaOH that has a pH of 11.50 8.2 x 10-2 M NaOH 3.2 x 10-3 M NaOH 2.50 M NaOH 3.2 x 10-12 M NaOH

3.2 x 10-3 M NaOH

If a 0.10 M solution of an unknown monoprotic weak acid has a pH of 4.73, what is Ka for this acid? 1.86 x 10E(-5) 3.5 x 10E(-10) 3.5 x 10E(-9) 1.86 x 10E(-10)

3.5 x 10E(-9)

For the reaction 2 NO + Cl2 -----> 2 NOCl at 400 K. What is the value of Kp if the equilibrium partial pressures of NO, Cl2and NOCl are 0.095, 0.171 and 0.28 atms respectively? 51 17 4.8

51

Radioactive decay is a classic first order process. The half-life of 14C is 5,730 yr's. If you started with 0.973 grams of 14C how long would it take to get to 0.00132 gram? 73,400 years 54,600 years 6,670 years 23,700 years

54,600 years

Identify the Bronsted-Lowry acid and the Bronsted-Lowry base on the left side of each of the following equations, and also identify the conjunction acid and conjugate base of each on the right side: (A) NH4+(aq) + CN-(aq)<--->HCN(aq) + NH3(aq) (B) (CH3)3N(aq) + H2O(l)<--->(CH3)3NH+(aq)+ OH-(aq) (C) HCOOH(aq) +PO43-(aq)<---> HCOO-(aq) + HPO42-(aq) Acid + Base <------> Conj. Acid +Conj. Basea) NH4+(aq) CN-(aq)HCN(aq) NH3(aq)b) H2O(l)(CH3)3N(aq)(CH3)3NH+(aq)OH-c) HCOOH (aq) PO43-(aq)HPO42-(aq) HCOO-(aq) Acid + Base <------> Conj. Acid +Conj. Basea) NH4+(aq) CN-(aq)HCN(aq) NH3(aq)b) (CH3)3N(aq)H2O(CH3)3NH+(aq)OH-c) HCOOH (aq) PO43-(aq)HPO42-(aq) HCOO-(aq) Acid + Base <------> Conj. Acid +Conj. Basea) NH4+(aq) CN-(aq)HCN(aq) NH3(aq)b) H2O(l)(CH3)3N(aq)OH-(CH3)3NH+c) HCOOH (aq) PO43-(aq)HPO42-(aq) HCOO-(aq) Acid + Base <------> Conj. Acid +Conj. Basea) NH4+(aq) CN-(aq)HCN(aq) NH3(aq)b) (CH3)3N(aq)H2O(CH3)3NH+(aq)OH-c) HCOOH (aq) PO43-(aq)HCOO-HPO42-(aq)

Acid + Base <------> Conj. Acid +Conj. Basea) NH4+(aq) CN-(aq)HCN(aq) NH3(aq)b) H2O(l)(CH3)3N(aq)(CH3)3NH+(aq)OH-c) HCOOH (aq) PO43-(aq)HPO42-(aq) HCOO-(aq)

What is the molecularity of each of the following elementary reaction? Write the rate law based upon this step as though it was the RDS. NO (g) + Cl2 (g) ---> NOCl2(g) Unimolecular & rate = k[NO] Bimolecular & rate = k[NO][Cl2]2 Unimolecular & rate = k[NO][Cl2] Bimolecular & rate = k[NO][Cl2]

Bimolecular & rate = k[NO][Cl2]

Once equilibrium is established the concentrations of the reactants and the products are equal to each other. True False

False

True or False Integrated rate laws (e.g. ln[A] = -kt + ln[A]) describe rate in terms of reactant concentration. True False

False

True or False The fastest step in the mechanism is called the rate determining step (RDS)? True False

False

True or False: The reaction below occurs when all 23 reactants simultaneously collide. 5 C2O42- + 2 MnO4- + 16 H+ ---------> 10 CO2 + 2 Mn2+ + 18 H2O False True

False

NH3(g) and HCI(g) react to form the iconic solid NH4CI(s). Which substance is the Bronsted- Lowry acid in this reaction? Which is the Bronsted- Lowry base? HCl is the Bronsted- Lowry base NH3 is the Bronsted- Lowry base HCl is the Bronsted- Lowry base NH3 is the Bronsted- Lowry acid HCl is the Bronsted- Lowry acid NH3 is the Bronsted- Lowry acid HCl is the Bronsted- Lowry acid NH3 is the Bronsted- Lowry base

HCl is the Bronsted- Lowry acid NH3 is the Bronsted- Lowry base

Lactic acid (CH3CH(OH)COOH) has one acidic hydrogen. A 0.10 M solution of lactic acid has a pH of 2.44. Calculate Ka. Ka= 1.4 x 10-4 3.8 x 10-2 3.6 x 10-3 7.1 x 10+3

Ka= 1.4 x 10-4

Write the expression for Kc for the following reaction. Indicate whether the reaction is homogeneous or heterogeneous. 2Ag (s) + Zn2+ (aq) <---> 2 Ag+ (aq) + Zn (s) Kc = [Zn][Ag+]2/[Zn2+][Ag]2 ; Heterogeneous Kc = [Ag+]/[Zn2+] ; Heterogeneous Kc = [Zn2+]/[Ag+]2 ; Heterogeneous Kc = [Ag+]2/[Zn2+] ; Heterogeneous

Kc = [Ag+]2/[Zn2+] ; Heterogeneous

Write the expression for Kc for the following reaction. Indicate whether the reaction is homogeneous or heterogeneous. Ni(CO)4 (g) <---> Ni (s) + 4CO (g) Kc = [Ni(CO)4]/[CO]4 ; Heterogeneous Kc = [CO]4/[Ni(CO)4] ; Heterogeneous Kc = [Ni][CO]4/[Ni(CO)4] ; Heterogeneous Kc = [Ni][CO]4/[Ni(CO)4] ; Homogeneous

Kc = [CO]4/[Ni(CO)4] ; Heterogeneous

Write the expression for Kc for the following reactions. Indicate whether the reaction is homogeneous or heterogeneous. H2O (l) <---> H+ (aq) + OH-(aq) Kc = [H+][OH-]/[H2O]2 ; Homogeneous Kc = [H+][OH-]/[H2O]2 ; Heterogeneous Kc = [H+][OH-] ; Homogeneous Kc = [H+][OH-] ; Heterogeneous

Kc = [H+][OH-] ; Heterogeneous

Write the expression for Kc for the following reaction. Indicate whether the reaction is homogeneous or heterogeneous. 3NO (g) <---> N2O (g) + NO2 (g) Kc = [N2O][NO2]/[NO]3 ; heterogeneous Kc = [NO]3/[N2O][NO2] ; homogeneous Kc = [N2O][NO2]/[NO]3 ; homogeneous Kc = [NO]3/[N2O][NO2] ; heterogeneous

Kc = [N2O][NO2]/[NO]3 ; homogeneous

Numerically speaking is the rate of disappearance of reactants always the same number as the rate of the appearance of products? Yes No and there is no way to make the equal No but they can always be made equal to each other by considering stoichiometry

No but they can always be made equal to each other by considering stoichiometry

Consider the potential energy vs reaction coordinate diagram in problem 70 in your text on pg 616. Which step is the slowest step? second fourth third first

Second

For the following exothermic reaction at equilibrium: 2 SO2 + O2 ------> 2 SO3 What is the effect of adding SO3? shifts towards products no effect Shifts towards reactants

Shifts towards reactants

The gas-phase decomposition of NO2, 2NO2(g) ---> 2NO (g) +O2 (g), is studied at 383°C, giving the following data: Time (s)[NO2] (M)0.00.1005.00.01710.00.009015.00.006220.00.0047 Is the reaction first order or second order with respect to NO2? The plot of 1/[NO2] versus time is linear, so the reaction is second-order. The plot of 1/[NO2] versus time is linear, so the reaction is first-order. The plot of [NO2] versus time is linear, so the reaction is zero-order. The plot of ln[NO2] versus time is linear, so the reaction is first-order.

The plot of 1/[NO2] versus time is linear, so the reaction is second-order.

True or false. The only things equal at equilibrium are the rates of the forward and reverse reactions. True False

True

Which factor is most sensitive to changes in temperature- X) the frequency of collisions, Y) the orientation factor, or Z) the fraction of molecules with energy greater than the activation energy? X, Y & Z are all equally sensitive Z X Y

Z

The acid-dissociation constant for benzoic acid (C6H5COOH) is 6.3 X 10-5. Calculate the equilibrium concentrations of H3O + C6H5COO-, and C6H5COOH in the solution if the initial concentration of C6H5COOH is 0.050 M. [H+]=[C6H5COO-]= 1.8 x 10-3 M [C6H5COOH]=0.0048 M [H+]=[C6H5COO-]= 3.2 x 10-6 M [C6H5COOH]=0.050 M [H+]=[C6H5COO-]= 3.2 x 10-6 M [C6H5COOH]=0.049 M [H+]=[C6H5COO-]= 1.8 x 10-3 M [C6H5COOH]=0.048 M

[H+]=[C6H5COO-]= 1.8 x 10-3 M [C6H5COOH]=0.048 M

A reaction has a Kc = 1 what does the position of the equilibrium favor? a mixture of roughly equal amounts of reactants and products favors reactants favors products

a mixture of roughly equal amounts of reactants and products

A mixture of 0.10 mol of NO, 0.050 mol of H2, and 0.10 mol of H20 is placed in a 1.0-L vessel at 300 k. The following equilibrium is established: 2NO (g) + 2H2 (g) <---> N2 (g) + 2H2O (g) at equilibrium [NO] = 0.062 M (a) Calculate the equilibrium concentration of H2O. (b) calculate Kc a) 0.138 M; b) 1.5 x 10E(-3) a) 0.012 M; b) 7 x 10E(+2) a) 0.019 M; b) 7 x 10E(+2) a) 0.138 M; b) 7 x 10E(+2)

a) 0.138 M; b) 7 x 10E(+2)

At 1000 K, Kp=1.85 for the reaction SO2(g) + 1/2O2 <---> SO3 (g) (a) what is the value of Kp, for the reaction SO3 (g) <--->SO2(g) + 1/2O2? (b) what is the value of kp, for the reaction 2SO2(g) + O2 <---> 2SO3 (g)? a) 1.85; b) 3.42 a) 0.54; b) 281 a) 0.54; b) 3.42 a) 0.54; b) 1.85

a) 0.54; b) 3.42

The following mechanism has been proposed for the gas phase reaction of H2 with ICl: H2 (g) + ICl(g) ---> HI (g) + HCl (g) HI (g) + ICl(g) ---> I2 (g) + HCl(g) (a) write the balanced equation for the overall reaction. (b) identify any intermediates in the mechanism. a) H2(g) + 2 ICl(g) --------> I2(g) + 2 HCl(g) b) ICl a) H2(g) + 2 ICl(g) + HI(g) --------> HI(g) + I2(g) + 2 HCl(g) b) HCl a) H2(g) + 2 ICl(g) --------> I2(g) + 2 HCl(g) b) HI a) H2(g) + 2 ICl(g) --------> I2(g) + 2 HCl(g) b) HCl

a) H2(g) + 2 ICl(g) --------> I2(g) + 2 HCl(g) b) HI

At 100°C, the equilibrium constant for the reaction COCl2(g) <---> CO(g) + Cl2 has the value kc=2.19 x 10-10. are the following mixtures of COCl2, CO, and Cl2 at 100°C at equilibrium? If not, indicate the direction that the reaction must proceed to achieve equilibrium. (a) [COCl2]= 2.00 x 10-3 M, [CO] = 3.3 x 10-6 M, [Cl2]= 6.62 x 10-6 M (b) [COCl2]= 4.50 x 10-2 M, [CO] = 1.1x 10-7 M, [Cl2]= 2.25 x 10-6 M (c) [COCl2]= 0.0100 M, [CO] = 1.48x 10-6 M, [Cl2]= 1.48 x 10-6M a) No; towards reactants b) No; towards reactants c) Yes at eq.; no changes a) No; towards reactants b) No; towards products c) No; towards products a) No; towards reactants b) No; towards products c) Yes at eq.; no changes a) No; towards reactants b) No; towards products c) No; towards reactants

a) No; towards reactants b) No; towards products c) Yes at eq.; no changes

Calculate [OH-] and pH for (a) 1.5 X 10-3 M Sr(OH)2 (b) 2.250g of LiOH in 250.0 mL of solution (c) 1.00 mL of 0.175 M NaOH diluted to 2.00 L (d) a soution formed by adding 5.00 mL of 0.105 M KOH to 15.0 mL of 9.5 X 10-2 M Ca(OH)2 a) [OH-]= 3.0 x 10-3 M, pH= 11.48 b) [OH-]= 0.3758 M, pH= 13.5750 c) [OH-]= 8.75 x 10-5 M, pH= 9.942 d) [OH-]= 0.17 M, pH= 13.23 a) [OH-]= 1.5 x 10-3 M, pH= 11.18 b) [OH-]= 0.3758 M, pH= 13.5750 c) [OH-]= 8.75 x 10-5 M, pH= 9.942 d) [OH-]= 0.17 M, pH= 13.23 a) [OH-]= 3.0 x 10-3 M, pH= 2.52 b) [OH-]= 0.3758 M, pH= 0.425 c) [OH-]= 8.75 x 10-5 M, pH= 4.06 d) [OH-]= 0.17 M, pH= 13.23 a) [OH-]= 3.0 x 10-3 M, pH= 11.48 b) [OH-]= 0.3758 M, pH= 13.5750 c) [OH-]= 8.75 x 10-5 M, pH= 4.06 d) [OH-]= 0.17 M, pH= 13.23

a) [OH-]= 3.0 x 10-3 M, pH= 11.48 b) [OH-]= 0.3758 M, pH= 13.5750 c) [OH-]= 8.75 x 10-5 M, pH= 9.942 d) [OH-]= 0.17 M, pH= 13.23

(a) For the generic reaction A ---> B. If this is a first-order reaction, what quantity when graphed versus time will yield a straight line? (b) how can you calculate the rate constant for the first-order reaction from the graph you made in part (a)? (a) a graph on [A] versus time yields a straight line for a first-order reaction. (b) the slope of the straight line. (a) a graph on 1/[A] versus time yields a straight line for a first-order reaction. (b) the slope of the straight line. (a) a graph on log[A] versus time yields a straight line for a first-order reaction. (b) the slope of the straight line. (a) a graph on ln[A] versus time yields a straight line for a first-order reaction. (b) the negative slope of the straight line.

a) a graph on ln[A] versus time yields a straight line for a first-order reaction. (b) the negative slope of the straight line.

When the following reactions come to equilibrium, does the equilibrium mixture contain mostly reactants or products? (a) 2NO(g) + O2 (g) <---> 2NO2 (g) Kc= 1.5 x 10-10 (b) 2SO2 (g) + O2 (g) <---> 2SO3 (g) Kp= 2.5 x 10 9 a) almost entirely products b) almost entirely reactants a) almost entirely reactants b) almost entirely products a) a mixture that strongly favors reactants b) a mixture that slightly favors products a) almost entirely reactants b) a mixture that slightly favors products

a) almost entirely reactants b) almost entirely products

The oxidation of SO2 to SO3 by O2 can involve NO2. The reaction proceeds according to the following mechanism: 2 NO2 (g) + 2 SO2 (g) ---> 2 NO (g) + 2 SO3 (g) 2NO (g) + O2 (g) --->2 NO2 (g) a) Do we consider NO2 a catalyst or an intermediate in this reaction? b) would you classify NO as a catalyst or an intermediate in this reaction? c) is this an example of homogeneous catalysis or heterogeneous catalysis? a) catalyst; b) intermediate & c) homogeneous a) intermediate b) catalyst & c) heterogeneous a) catalyst; b) intermediate & c) heterogeneous a) intermediate; b) catalyst & c) homogeneous

a) catalyst; b) intermediate & c) homogeneous

The equilibrium constant for the reaction 2NO (g) + Br2 (g) <---> 2NOBr (g) is Kc= 1.3 x 10-2 at 1000K. (a) at this temperature does the equilibrium favor NO or Br2 or does it favor NOBr? (b) calculate Kc for 2NOBr (g) <---> 2 NO (g) + Br2 (g) (c) alculate Kc for NOBr (g) <---> NO (g) +1/2 Br2 (g) a) it favors the reactants; b) 76.9; c) 8.77 a) it favors the reactants; b) 76.9; c) 5914 a) it favors the reactants; b) 5914; c) 76.9 a) it favors the products; b) 76.9; c) 8.77

a) it favors the reactants; b) 76.9; c) 8.77

Consider the following equilibrium for which Δ H< 0 2SO2(g) + O2(g) <---> 2SO3(g) How will each of the following changes affect an equilibrium mixture of the three gases: (a) a catalyst is added to the mixture (b) the total pressure of the system is increased by adding a noble gas (c) SO3 (g) is removed from the system a) no effect on the position of the equilibrium; b) no effect on the position of the equilibrium; c) shifts towards products a) no effect on the position of the equilibrium; b) no effect on the position of the equilibrium; c) shifts towards reactants a) no effect on the position of the equilibrium; b) shifts towards products; c) shifts towards products a) no effect on the position of the equilibrium; b) shifts towards reactants; c) shifts towards products

a) no effect on the position of the equilibrium; b) no effect on the position of the equilibrium; c) shifts towards products

The following data were measured for the reaction BF3(g) + NH3(g) ---> F3BNH3(g) Experiment[BF3] (M)[NH3] (M) initial rate (M/s) 1-0.2500.2500.213020.2500.1250.106530.2000.1000.068240.3500.1000.119350.1750.1000.0596 (a) what is the rate law for the reaction? (b) what is the overall order of the reaction? a) r = k[BF3]1/2 [NH3]1/2 b) 1 a) r = k[BF3][NH3] b) 2 a) r = k[BF3][NH3] b) 1 a) r = k[BF3]1.75 [NH3]2 b) 3.75

a) r = k[BF3][NH3] b) 2

The following data were measured for the reaction 2 NO(g) + Br2(g) ---> 2 NOBr(g) Experiment[NO] (M)[Br2] (M) initial rate (M/s) 1 0.10 0.202420.250.2015030.100.506040.350.50735 (a) what is the rate law for the reaction? (b) what is the overall order of the reaction? a) r = k[NO]2[Br2] b) 3 a) r = k[NO]3[Br2] b) 4 a) r = k[NO]4[Br2]2 b) 6 a) r = k[NO]2[Br2] b) 2

a) r = k[NO]2[Br2] b) 3

How do the following changes affect the value of the equilibrium constant for a gas-phase endothermic reaction: (a) removal of product (b) decrease in volume (c) decrease in temperature a) shifts towards reactants; b) shifts to the side with the least number of moles of gas; c) shifts towards reactants/new smaller K a) shifts towards products; b) shifts to the side with the greatest number of moles of gas; c) shifts towards reactants/new smaller K a) shifts towards products; b) shifts to the side with the least number of moles of gas; c) shifts towards reactants/new smaller K a) shifts towards products; b) shifts to the side with the least number of moles of gas; c) shifts towards products/new bigger K

a) shifts towards products; b) shifts to the side with the least number of moles of gas; c) shifts towards reactants/new smaller K

Consider the following equilibrium for which Δ H< 0 2SO2(g) + O2(g) <---> 2SO3(g) How will each of the following changes affect an equilibrium mixture of the three gases: (a) O2(g) is added to the system; (b) the reaction mixture is heated (c) the volume of the reaction vessel is doubled a) shifts towards products; b) shifts towards reactants/new K with a smaller numerical value; c) shifts towards reactants a) shifts towards reactants; b) shifts towards reactants/new K with a smaller numerical value; c) shifts towards reactants a) shifts towards products; b) shifts towards reactants/new K with a smaller numerical value; c) shifts towards products a) shifts towards products; b) shifts towards products/new K with a bigger numerical value; c) shifts towards reactants

a) shifts towards products; b) shifts towards reactants/new K with a smaller numerical value; c) shifts towards reactants

How do the following changes affect the value of the equilibrium constant for a gas-phase endothermic reaction: (a) removal of a reactant (b) addition of a catalyst a) shifts towards reactants; b) no effect a) shifts towards products; b) no effect a) shifts towards reactants; b) shifts towards products a) no effect; b) no effect

a) shifts towards reactants; b) no effect

(a) if Qc<Kc in which direction will the reaction process in order to reach the equilibrium? (b) what condition must be satisfied so that Qc= Kc? a) towards products; b) equilibrium concentrations/at equilibrium a) towards products; b) same total pressure a) towards reactants; b) equilibrium concentrations/at equilibrium a) towards products; b) at the same temperature

a) towards products; b) equilibrium concentrations/at equilibrium

Is each of the following statements true or false? (a) all strong acids contain one or more H atoms. (b) A strong acid is a strong electrolyte. (c) A 1.0-M solution of a strong acid will have a pH= 1.0. a) true b) true c) true a) true b) true c) false a) true b) false c) true a) false b) true c) true

a) true b) true c) false

Which of the things listed below are factors that can affect the rate of a chemical reaction? a) Temperature b) Phase c) Reactant Concentration d) A Catalyst e) Partial Pressure of a Reactant f) Total Pressure on a solution state reaction g) Vapor Pressure of the solvent a, b, c, d & e all are true/a through g a, b, c & d a & d only

a, b, c, d & e

If Q = K which way does the reaction proceed towards equilibrium? towards reactants towards products at equilibrium

at equilibrium

What kind of a pH is 11.50? neutral basic acidic

basic

What of the following statements is true with regard to the rate-determining step of a reaction mechanism? it is the slowest step in the mechanism and the experimental rate law can be written from this elementary step it is the slowest step in the mechanism and the experimental rate law can not be written from this elementary step it is the fastest step in the mechanism and the experimental rate law can be written from this elementary step it is neither the slowest step in the mechanism nor the fastest step, but the experimental rate law can be written from this elementary step

it is the slowest step in the mechanism and the experimental rate law can be written from this elementary step

A reaction 2 A + 3 B ---> 2 C obeys the following rate law: Rate= k[B]2. If the initial concentration of A is doubled, how will the rate change? it will double it will quadruple it will not change at all it will decrease by 1/2

it will not change at all

Consider the following equilibrium between ozone and molecular oxygen in the stratosphere. 2 O3(g)<----> 3 O2(g) ΔH = - 284.6 kJ How would a decrease in temperature effect this equilibrium? no effect molecular oxygen concentration increases molecular oxygen concentration decreases ozone concentration increases

molecular oxygen concentration increases

What kind of a pH is 7.00? acidic basic neutral

neutral

Consider the following equilibrium between ozone and molecular oxygen in the stratosphere. 2 O3(g)<----> 3 O2(g) How would an increase in total pressure effect this equilibrium? This increase in total pressure in accompanied by an increase in gas density. no effect molecular oxygen concentration increases ozone concentration increases ozone concentration decreases

ozone concentration increases ozone concentration decreases

Butyric acid (C3H7CO2H) has a pka of 4.84. What is the pH of a 0.050 M sodium butyrate solution? pH = 9.16 pH = 3.07 pH = 8.77 pH = 5.23

pH = 8.77

The following mechanism has been proposed for the gas phase reaction of H2 with ICl: H2 (g) + ICl(g) ---> HI (g) + HCl (g) HI (g) + ICl(g) ---> I2 (g) + HCl(g) If the first step is slow and the second one is fast, which rate law do you expect to be observed for the overall reaction? r = k[H2][ICl]2 r = k[H2] r = k[HI][ICl] r = k[H2][ICl]

r = k[H2][ICl]

If Q < K which way does the reaction proceed towards equilibrium? towards reactants towards products No answer text provided. at equilibrium

towards products

Which name below best describes ammonia? weak acid weak base strong acid strong base

weak base

Which name below best describes phosphate ion? strong acid strong base weak acid weak base

weak base