Reference no: EM13994215

Question 1 In an equilibrium process, the concentrations of products and of reactants are equal.

True

False

Flag this QuestionQuestion 2 A heterogeneous catalyst is a catalyst that is in two phases of matter. 

True

False

Flag this QuestionQuestion 3 Br∅nsted and Lowry suggested that bases be defined as proton acceptors.  

True

False

Flag this QuestionQuestion 4 The value of the equilibrium constant for a given reaction depends on the initial concentrations of reactants.

True

False

Flag this QuestionQuestion 5

H2SO4 is a weaker acid than H2SO3. 

True

False

Flag this QuestionQuestion 6 The term pH = -ln [H+].

True

False

Flag this QuestionQuestion 7 Both products and reactants will be present in an equilbirium reaction unless K is very small or very large 

True

False

Flag this QuestionQuestion 8 The rate of a specific chemical reaction is independent of the concentrations of the reactants. Thus the reaction is zero order. 

True

False

Flag this QuestionQuestion 9 In the Arrhenius equation, ln k = -Ea/RT + ln A, the symbol A denotes the initial concentration of A.

True

False

Flag this QuestionQuestion 10 When a liquid is in equilibrium with its vapor in a closed container:

the amount of gas in the container must exactly equal the amount of liquid

the vapor will gradually change back to the liquid state, that is, no vapor will be left

a change in temperature will not change the pressure in the container

the rate at which molecules from the liquid phase enter the gas phase exactly equals the rate at which molecules from the gas phase pass into the liquid phase

molecules cannot go from the liquid phase to the gas phase because the amount of liquid in the container is constant

Flag this QuestionQuestion 11 138.0 grams of ethanol (46.0 g/mol), 99.0 grams of water (18.0 g/mol), and 80.0 grams of methanol (32.0 g/mol) comprise a solution. What is the mole fraction of methanol present in the solution?

0.252

0.273

0.227

0.338

0.294

Flag this QuestionQuestion 12 Choose the strongest acid.

H2CO3

HF

HCN

HC2H3O2

HClO4

Flag this QuestionQuestion 13 A 1.00 molal solution of NaCl in water contains:

1.00 g NaCl per 1000.0 g H2O

1.00 mol NaCl per 1000.0 g H2O

1000.0 g NaCl per 1000.0 g H2O

1.00 mol NaCl per 1000.0 mol H2O

1.00 mol NaCl per 1000.0 kg H2O

Flag this QuestionQuestion 14 A solid solution of zinc in copper is an example of:

a solvent

an alloy

a non-uniform solute

a solute

the U.S. five-cent nickel

Flag this QuestionQuestion 15 A solution has pOH of -0.47. This means that:

The solution has an [H+] = 2.95 M

the solution has an [OH-] = 0.34 M

the solution has an [OH-] greater than 10.0 M

the solution has an [OH-] = 2.95 M

the solution has a pH of 13.53

Flag this QuestionQuestion 16 The reaction has the rate law Rate = k[A][B]2. Which will cause the rate to increase the most?

quadrupling [A]

lowering temperature

doubling [B]

doubling [A]

tripling [B]

Flag this QuestionQuestion 17 For the reaction: 2N2O5(g) → 4NO2(g) + O2(g) the rate law is:

(Δ[O2]/Δt) = k[N2O5]

At 300 K, the half-life is 2.50 × 104 seconds and the activation energy is 103.3 kJ/mol O2. At the time when N2O5 is being consumed at a rate of 1.2 × 10-4 M/s, what is the rate at which NO2 is being formed?

3.0 × 10-5 M/s

1.2 × 10-4 M/s

4.8 × 10-4 M/s

2.4 × 10-4 M/s

6.0 × 10-5 M/s

Flag this QuestionQuestion 18 For the reaction 2HgCl2 + C2O42- → products, data are:

[HgCl2]0.08360.08360.0418 M

[C2O42-]0.2020.4040.404 M

Init. rate0.261.040.53 M/hr

The rate law is Rate = [HgCl2]x[C2O42-]y. Thus:

x = 1, y = 2

x = 0, y = 2

x = 2, y = 2

x = 2, y = 1

x = 1, y = 1

Flag this QuestionQuestion 19 For a first order reaction with a half-life of 75.0 min, what is K?

1.54 × 10-4 min-1

9.24 × 10-3 min-1

2.67 × 10-2 min-1

52.0 min-1

1.33 × 10-2 min-1

 

Flag this QuestionQuestion 20 What is the rate constant at 305 K for the reaction: 

2N2O5 → 2N2O4 + O2,  

if k = 3.46 × 10-5 s-1 at 298 K and Ea = 106 kJ/mol?

2.4 × 10-5 s-1

4.8 × 10-5 s-1

1.2 × 10-5 s-1

9.2 × 10-5 s-1

6.0 × 10-5 s-1

Flag this QuestionQuestion 21 What is the rate law for the following reaction and its mechanism? 

2HgCl2 + C2O42- → 2Cl- + 2CO2 + Hg2Cl2 (overall reaction) 

HgCl2 + C2O42- ? HgCl2C2O42-(F) 

HgCl2C2O42- + C2O42- → Hg + 2C2O4Cl2-(S)

Hg + HgCl2 → Hg2Cl2(F) 

2C2O4Cl2- → C2O42- + 2Cl- + 2CO2 (F)

Rate = k[Hg2Cl2]

Rate = k[HgCl2]2[C2O42-]2

Rate = k[HgCl2]2[C2O42-]

Rate = k[HgCl2][C2O42-]2

Rate = k[HgCl2][C2O42-]

 

Flag this QuestionQuestion 22 If a reaction is first order with a rate constant of 5.48 × 10-2/sec, how long is required for 3/4 of the initial concentration of reactant to be used up?

36.5 sec

25.3 sec

6.3 sec

18.2 sec

50.6 sec

 

Flag this QuestionQuestion 23 For the reaction: H2(g) + I2(g) ⇔ 2 HI(g), Kc = 92.0 When equilibrium concentrations of HI and I2 are 

[HI] = 0.115 M and [I2] = 0.250 M, the equilibrium concentration of [H2] is:

5.75 × 10-4 M

5.00 × 10-3 M

9.56 M

0.135 M

1.74 × 103 M

 

Flag this QuestionQuestion 24 0.653 g of a monoprotic solid acid (mm = 157 g/mol) is dissolved in water to produce 50.0 mL of a solution with pH = 2.13. Determine the ionization constant of the acid.

3.6 × 10-6

7.9 × 10-3

3.9 × 10-2

6.6 × 10-4

8.9 × 10-2

 

Flag this QuestionQuestion 25 For the following chemical equilibrium, Kp = 4.6 × 10-14 at 25 °C, find the value of Kc for this reaction at 25 °C. 

2 Cl2(g) + 2 H2O(g) ⇔ 4 HCl(g) + O2(g)

Kc = 1.9 × 10-15

Kc = 1.1 × 10-12

Kc = 2.2 × 10-14

Kc = 4.6 × 10-14

Kc = 9.4 × 10-14

 

Flag this QuestionQuestion 26 Choose the Br∅nsted-Lowry acids and bases in the following equation: 

NH4+ + OH- ⇔ H2O + NH3

acids NH4+, OH-bases NH4+, H2O

acids OH-, H2Obases NH3, NH4+

acids NH4+, OH-bases H2O, NH3

acids NH4+, NH3bases OH-, H2O

acids NH4+, H2Obases OH-, NH3

 

Flag this QuestionQuestion 27 For the reaction CO(g) + 3 H2(g) → H2O(g) + CH4(g), Kc = 190 at 1000 K. If a vessel is filled with these gases such that the initial concentrations are [CO] = 0.036M, [H2] = 0.045, [H2O] = 0.020, and [CH4] = 0.031, in which direction will a reaction occur and why?

toward products because Q = 0.38

toward reactants because Q = 61

toward reactants because Q = 0.24

it is at equilibrium

toward products because Q = 4.1

 

Flag this QuestionQuestion 28 2.5 moles H2O and 100 g of C are placed in a 50-L container. At equilibrium for the reaction C(s) + H2O(g) ⇔ CO(g) + H2(g), [H2] = 0.040 M. Which of the following is true? 

no carbon is left

[H2O] = 0.020 M

[CO] = 0.020 M

[H2O] = 0.010 M

none of these

 

Flag this QuestionQuestion 29 For CO2(g) + H2(g) ⇔ CO(g) + H2O(g), Kc = [CO][H2]/[CO2][H2], if there are 1.43 mols each of CO and H2, 0.572 mol H2 and 4.572 mols CO2, in a 4.0 L container at equilibrium, what is Kc?

0.547

1.28

0.137

0.782

2.34

 

Flag this QuestionQuestion 30 What is the pH of a 0.250 M solution of formic acid? Ka = 1.8 × 10-4

5.4

11.8

2.2

0.60

8.6

 

Flag this QuestionQuestion 31 The Kb value for methylamine is 4.2 × 10-4. What is the pH of an aqueous solution for which the label reads "0.042 M CH3NH2"?

11.6

4.8

2.4

9.2

12.3

 

Flag this QuestionQuestion 32

Which one of the following combinations cannot be a buffer solution?

HCN  and  KCN

NH3  and  (NH4)2SO4

HNO3  and  NaNO3

HF  and  NaF

HNO2  and  NaNO2    Type MC

 

Flag this QuestionQuestion 33

For AgCl, Ksp = 1.8 ´ 10-10. What will occur if 250 mL of 1.5 ´ 10-3 M NaCl is mixed with 250 mL of 2.0 ´ 10-7 M AgNO3?

A precipitate will form because P > Ksp.

A precipitate will form because Ksp > P.

No precipitate will form because P = Ksp.

No precipitate will form because P > Ksp.

No precipitate will form because Ksp > P.   Type MC

 

Flag this QuestionQuestion 34

Which of the boxes below represents solid MX2 in equilibrium with M2+ (squares) and X- (circles)?

 

Flag this QuestionQuestion 35

What is the free Ag+ concentration when equal volumes of 0.020 M Ag+  and 2.0 M NH3 are mixed.  Kf for [Ag(NH3)2]+ is 1.6 x 107.

1.3 x 10-10

2.0 x 10-14

6.3 x 10-8

6.5 x 10-10

3.1 x 10-10

 

Flag this QuestionQuestion 36

Equal volumes of a 0.020 M Zn+2 solution and a 2.0 M NH3 solution are mixed.  Kf for [Zn(NH3)4]2+ is 4.1 x 108.  If enough sodium oxalate is added to make the solution 0.10 M in oxalate (C2O42-) will ZnC2O4 precipitate.  Ksp of ZnC2O4 is 2.7 x 10-8.

yes, Q = 11

yes, Q = 2.9 x 10-12

no, Q = 2.9 x 10-12

yes, Q = 2.4 x 10-9

no, Q = 2.4 x 10-9

no, Q = 11