Topic 9 Practice - Kinetics and Equilibrium
1. In most aqueous reactions as temperature increases, the
effectiveness of collisions between reacting particles
A) decreases
C) remains the same
B) increases
2. As the concentration of reacting particles increases, the
rate of reaction generally
A) decreases
C) remains the same
B) increases
3. Given the balanced equation representing a phase
change:
C6H4Cl 2(s) + energy
C6H4Cl 2(g)
Which statement describes this change?
A)
B)
C)
D)
It is endothermic, and entropy decreases.
It is endothermic, and entropy increases.
It is exothermic, and entropy decreases.
It is exothermic, and entropy increases.
7. Given the equation representing a system at equilibrium:
H2O (s)
H20 (l)
At which temperature does this equilibrium exist at
101.3 kilopascals?
A) 0 K
B) 0°C
C) 32 K
8. Given the reaction at equilibrium:
2 A(g) + 3 B(g) « A2B3(g) + heat
Which change will not affect the equilibrium
concentrations of A(g), B(g), and A2B3(g)?
A)
B)
C)
D)
adding more A(g)
adding a catalyst
increasing the temperature
increasing the pressure
4. Based on the nature of the reactants in each of the
equations below, which reaction at 25°C will occur at
the fastest rate?
A) C(s) + O 2(g)
CO 2(g)
B) NaOH(aq) + HCl(aq)
NaCl(aq) + H2O( )
C) CH 3OH( ) + CH3COOH( )
CH 3COOCH 3(aq)
+ H2O( )
D) CaCO 3(s)
CaO(s) + CO 2(g)
5. Given the balanced equation:
Which statement best describes this process?
A) It is endothermic and entropy increases. B) It is endothermic and entropy decreases.
C) It is exothermic and entropy increases.
D) It is exothermic and entropy decreases.
6. A student observed that the temperature of water
increased when a salt was dissolved in it. The student
should conclude that dissolving the salt was
A)
B)
C)
D)
involved in the formation of an acidic solution
involved in the formation of a basic solution
an exothermic reaction
an endothermic reaction
D) 273°C
9. Given the balanced equation representing a reaction:
2HCl(aq) + Na 2S2O3(aq)
S(s) + H 2SO 3(aq) + 2NaCl(aq)
Decreasing the concentration of Na 2S2O3(aq) decreases the rate of reaction because the
A)
B)
C)
D)
activation energy decreases
activation energy increases
frequency of effective collisions decreases
frequency of effective collisions increases
10. Given the equation representing a system at
equilibrium:
N2(g) + 3H 2(g) « 2NH 3(g) + energy
Which changes occur when the temperature of this
system is decreased?
A) The concentration of H2(g) increases and the
concentration of N2(g) increases.
B) The concentration of H2(g) decreases and the
concentration of N2(g) increases.
C) The concentration of H2(g) decreases and the
concentration of NH 3(g) decreases.
D) The concentration of H2(g) decreases and the
concentration of NH 3(g) increases.
13. Systems in nature tend to undergo changes toward
A)
B)
C)
D)
lower energy and less disorder
lower energy and more disorder
higher energy and less disorder
higher energy and more disorder
14. Which 1-mole sample has the least entropy?
A) Br2(s) at 266 K
C) Br 2( ) at 332 K
B) Br 2( ) at 266 K
D) Br 2(g) at 332 K
15. Given the potential energy diagram representing a
reversible reaction:
11. Given the equation representing a reaction at
equilibrium:
H2(g) + I 2(g) + heat
2HI(g)
Which change favors the reverse reaction?
A)
B)
C)
D)
decreasing the concentration of HI(g)
decreasing the temperature
increasing the concentration of I 2(g)
increasing the pressure
12. Given the system at equilibrium:
PbCO3(s) « Pb2+(aq)
+
CO32–(aq)
How will the addition of Na2CO3(aq) affect [Pb2+](aq)
and the mass of PbCO3(s)?
A) [Pb 2+](aq) will decrease and the mass of PbCO 3(s)
Will decrease.
B) [Pb 2+](aq) will decrease and the mass of PbCO 3
(s) will increase.
C) [Pb 2+](aq) will increase and the mass of PbCO 3(s)
will decrease.
D) [Pb 2+](aq) will increase and the mass of PbCO 3(s)
will increase.
The activation energy for the reverse reaction is
represented by
A) A + B
C) B + D
B) B + C
D) C + D
Answer Key
Topic 9 Practice SHORT
1.
B
2.
B
3.
B
4.
B
5.
A
6.
C
7.
B
8.
B
9.
C
10.
D
11.
B
12.
B
13.
B
14.
A
15.
B