Thermochemistry
Equilibrium
Electrochemistry
Kinetics
Acids & Bases
100
In a reaction where entropy decreases, it is found that the reaction has a positive Delta G, but becomes spontaneous as the temperature decreases. Which of the following is true? (A) Delta S and Delta H are both positive (B) Delta S and Delta H are both negative (C) Delta S is negative and Delta H is positive (D) Delta S is positive and Delta H is negative (E) Delta S and Delta G are both equal to zero
B; Delta S and Delta H are both negative
100
In an gaseous, exothermic reaction, which of the following changes makes NO difference to the position of equilibrium? (A) Change of temperature (B) Adding more reactants (C) Removing products (D) Changing the volume (E) Adding a catalyst
E; Adding a catalyst
100
Which of the following statements is FALSE? (A) Oxidation involves a loss of electrons (B) Reduction involves a gain of electrons (C) A cell can be used to determine a value of Delta G for a REDOX reaction (D) A spontaneous REDOX reaction has a positive Ecell voltage (E) Electrolysis of aqueous potassium chloride will yield potassium metal at the cathode
E; Electrolysis of aqueous potassium chloride will yield potassium metal at the cathode
100
Consider the reaction X + Y ==> Z. Which rate law corresponds to a reaction where doubling both the concentration of X and Y would lead to the rate increasing by a factor of 16? (A) Rate = k [Y] (B) Rate = k [X]2[Y]2 (C) Rate = k [X] [Y]2 (D) Rate = k [X]2 (E) Rate = k
B; Rate = k [X]2[Y]2
100
Which of the following substances can act as a Lewis Base? (A) Nitric Acid (B) HCN (C) Carbonic Acid (D) Water (E) HF
D; water
200
When burning a solid hydrocarbon, which set of values would be most likely? (A) Negative Delta H, Negative Delta S, Negative Delta G (B) Negative Delta H, Negative Delta S, Positive Delta G (C) Negative Delta H, Positive Delta S, Negative Delta G (D) Positive Delta H, Negative Delta S, Negative Delta G (E) None of the above
C; Negative Delta H, Positive Delta S, Negative Delta G
200
A reaction is found to have an extremely large Kc = 4.1 x 1015. Which of the following statements cannot be determined from the value of the equilibrium constant? (A) The reaction converts nearly all of the reactants to products (B) The reaction will have a negative Delta G (C) There will be high concentration of products at equilibrium (D) The reverse reaction will have a very small Kc (E) The forward reaction is very fast
E; The forward reaction is very fast
200
The following REDOX reactions all have positive Ecell voltages. Cl2 + 2Br- ==> Br2 + 2Cl- Br2 + 2I- ==> I2 + 2Br- Cl2 + 2I- ==> I2 + 2Cl- Which is the correct order of strength of oxidizing agent, from weakest to strongest? (A) Chlorine < Iodine < Bromine (B) Bromine < Chlorine < Iodine (C) Iodine < Bromine < Chlorine (D) Chlorine < Bromine < Iodine (E) Iodine < Chlorine < Bromine
C; Iodine < Bromine < Chlorine
200
All of the following statements are true of a possible mechanism for a reaction except one. Which one is NOT true? (A) A multi-step mechanism will have one step that is rate determining (B) The mechanism will have steps that sum together to equal the overall reaction (C) The reaction will have a rate equation that includes only the reactants that appear in the slow step of the mechanism (D) If intermediates are present in the mechanism they will cancel out when considering the overall equation for the reaction (E) The reaction will have a rate equation that includes all the reactants that appear in all the steps of the mechanism
E; The reaction will have a rate equation that includes all the reactants that appear in all the steps of the mechanism
200
Which of the following salts will produce an acidic solution? (A) Sodium nitrate (B) Potassium nitrate (C) Ammonium chloride (D) Sodium Ethanoate (E) Potassium chloride
C; Ammonium chloride
300
Which of the following equations represents BOTH the standard enthalpy of formation of zinc oxide, AND the standard enthalpy of combustion of zinc? (A) Zn(s) + 0.5 O2(g) ==> ZnO(s) (B) Zn(g) + 0.5 O2(g) ==> ZnO(s) (C) Zn(s) + O(g) ==> ZnO(s) (D) Zn(g) + O(g) ==> ZnO(s) (E) None of the above
A;Zn(s) + 0.5 O2(g) ==> ZnO(s)
300
When a solution of Cu (II) ions are mixed with a concentrated ammonia solution an equilibrium is set up according to the equation below. The complex ion formed is royal blue in color. Which operation would have the effect of decreasing the intensity of the blue coloration? Cu2+(aq) + NH3(aq) <==> [Cu(NH3)4]2+(aq) (A) Filtering the mixture (B) Increasing the concentration of Cu (II) ions (C) Adding more NH3 (D) Adding an ion that precipitates the Cu2+ out of solution (E) Adding a catalyst
D; Adding an ion that precipitates the Cu2+ out of solution
300
When group I metal salts in solution are electrolyzed, hydrogen gas is produced at the cathode, rather than the free metal. This is because; (A) Aqueous solutions of group I metals do not conduct electricity (B) Group I metal salts are insoluble (C) Water is more easily reduced than group I metal ions in solution (D) The voltage required for the reaction is too high (E) None of the above
C; Water is more easily reduced than group I metal ions in solution
300
For the chemical reaction H2 + Cl2 ==> 2HCl, what can be said of the relative rates of consumption of the reactants when compared to the formation of products? (A) HCl will be produced at the same rate that chlorine is consumed (B) HCl will be produced at half the rate that chlorine is consumed (C) HCl will be produced at twice the rate that chlorine is consumed (D) It is not possible to tell anything about relative rates of consumption and formation from the chemical equation (E) None of the above
C; HCl will be produced at twice the rate that chlorine is consumed
300
Which indicator is suitable for use when titrating a strong acid with a weak base? (A) Phenolpthalein (B) Methyl Orange (C) Litmus (D) Any indicator (E) None of the Above
B; Methyl Orange
400
Given the following reactions Fe2O3 (s) + 3CO (s) ¬ 2Fe (s) + 3CO2 (g) ΔH = -28.0 kJ 3Fe (s) + 4CO2 (s) ¬ 4CO (g) + Fe3O4 (s) ΔH = +12.5 kJ the enthalpy of the reaction of Fe2O3 with CO 3Fe2O3 (s) + CO (g) ¬ CO2 (g) + 2Fe3O4 (s) is ________ kJ. A) 40.5 B) +109 C) -15.5 D) -109 E) -59.0
E; -59.0 kj
400
If an industrial, commercial, chemical process that involves establishing an equilibrium reaction is found to favor products at low temperatures, what is the most likely reason that the reaction is NOT actually run at very low temperatures? (A) Low temperatures are difficult to achieve (B) The yield of products is poor at low temperatures (C) Higher temperatures will yield more products (D) The manufacturer is not concerned about the yield of products (E) At low temperatures the reaction is too slow
E; At low temperatures the reaction is too slow
400
Iron rusts when it comes into contact with water and oxygen. The change that the iron undergoes can be summarized thus; Fe ==> Fe2+ + 2e-. When iron metal is coated with solid zinc in a process called galvanizing, the oxidation of iron is prevented even if the zinc coating does not completely cover the iron metal. Which of the following statements serves best to explain these observations? (A) Solid zinc metal is more easily reduced than iron (B) Solid zinc metal is more easily oxidized than iron (C) Zinc ions are more easily reduced than iron (D) Zinc ions are more easily oxidized than iron (E) Solid zinc metal is more easily reduced than iron (II) ions
B; Solid zinc metal is more easily oxidized than iron
400
In an equilibrium reaction that has been catalyzed, all of the following statements are true, EXCEPT; (A) In the catalyzed reaction the rate of both the forward AND backward reactions are increased (B) In the catalyzed reaction equilibrium will be achieved more quickly (C) The catalyst will be unchanged at the end of the reaction (D) In the catalyzed reaction K for the forward reaction will be larger (E) The catalyst will have the effect of providing a reaction pathway with a lower activation energy
D; In the catalyzed reaction K for the forward reaction will be larger
400
The salt BX, when dissolved in water, produces an acidic solution. Which of the following could be true? A) HX is a weak acid B)HX is a strong acid C)The cation B+ is a weak acid D)A, B, and C are all true E) A and C are both true
C; The cation B+ is a weak acid
500
Given the data in the table below, Delta Hrxn for the reaction IF7 (g) + I2 (g) ¬ IF5 (g) + 2IF (g) is ________ kJ. Substance Delta H (kJ/mol) IF (g) -95 IF5 (g) -840 IF7 (g) -941 A) 311 kJ B) 69 kJ C) -1991 kJ D) -69 kJ E) The Delta H of I2 (g) is needed for the calculation.
E; The Delta H of I2 (g) is needed for the calculation.
500
Consider the reaction below. As the temperature of the equilibrium mixture is increased, it is found that the % of N2O4 in the equilibrium mixture increases. What can be deduced about the enthalpy change in this reaction? N2O4(g) <==> 2NO2(g) (A) The forward reaction is exothermic (B) The backward reaction is exothermic (C) Delta H = 0 (D) Nothing (E) None of the above
A; The forward reaction is exothermic
500
. In the spontaneous reduction of Copper (II) ions with Nickel metal to form Copper metal and Nickel (II) ions, what will happen to the Ecell value when the concentration of Copper (II) ions is increased? Cu2+ + 2e- <====> Cu (+0.34V) Ni2+ + 2e- <====> Ni (-0.25V) (A) Ecell will increase (B) Ecell will decrease (C) Ecell will be unchanged (D) Not enough information to tell (E) None of the above
A; Ecell will increase
500
25. Questions 25-26 H3AsO4 + 3I−+ 2 H3O+  H3AsO3 + I3− + H2O The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the stoichiometry shown above. The experimental rate law of the reaction is: Rate = k [H3AsO4] [I−] [H3O+] 25. What is the order of the reaction with respect to I−? (A) 1 (B) 2 (C) 3 (D) 5 (E) 6
A; 1
500
Nitric acid is a strong acid. This means that __________. A) HNO3 produces a gaseous product when it is neutralized B) HNO3 cannot be neutralized by a weak base C) HNO3 does not dissociate at all when it is dissolved in water D) HNO3 dissociates completely to H+(aq) and NO3-(aq) when it dissolves in water E) aqueous solutions of HNO3 contain equal concentrations of H+(aq) and OH-(aq)
D; HNO3 dissociates completely to H+(aq) and NO3-(aq) when it dissolves in water
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