Download CHEM WKST: EQUILIBRIUM / LE CHATELIER`S PRINCIPLE

CHEM WKST: EQUILIBRIUM / LE CHATELIER’S PRINCIPLE
1)
2)
a)
A catalyst lowers the activation energy. Therefore, more particles will have enough energy to react.
b)
Increasing the temperature will increase the energy of the particles so that more will have enough energy to
meet the activation energy requirement.
a)
2SO2(g) + O2(g) ⇄ 2SO3(g)
[SO3 ]
2
2
[SO2 ] [O2 ]
b)
4NH3(g) + 3O2(g) ⇄ 2N2(g) + 6H2O(l)
[N2 ]
2
4
[NH3 ] [O2 ]
c)
2KClO(s) ⇄ 2KCl(s) + 3O2(g)
[O2 ]
d)
3
3
3Cu(s) + 8HNO3(aq)  3Cu(NO3)2(aq) + 2NO(g) + 4H2O(l)
3
[Cu(NO3 )2 ] [NO]
[HNO3 ]
3)
2
8
2NO(g) ⇄ N2(g) + O2(g)
K=
[N2 ][O2 ]
[NO]
2
-4
4.1 x 10 =
(0.0250 M)(0.0250 M)
x2
4.1 x 10ˉ4 x2 = 6.25 x 10ˉ4
x2 = 1.5244
x = 1.2 M
4)
2N2O(g) + 3O2(g) ⇄ 4NO(g)
K=
[NO]
2
4
[N2 O] [O2 ]
3
=
(4.20 x 10
2
-5
M)
4
(0.0335 M) (0.0280 M)
-10
3
= 1.26 x 10
1
5)
PCl5(g) ⇄ PCl3(g) + Cl2(g)
K=
[PCl3 ][Cl2 ]
[PCl5 ]
0.0730 =
(x)(x)
0.425 M
0.0310 = x2
x = 0.176 M
6) For the reaction CH4(g) + H2O(g) ⇄ CO(g) + 3H2(g) + heat
tell in which direction the equilibrium will shift for each of the following cases.
a) Some H2O(g) is removed.
shifts ←
b) The temperature is increased.
shifts ←
c) An inert gas is added.
no shift
d) The pressure increases.
shifts ←
e) Some CO(g) is removed.
shifts →
f) The volume of the container is tripled.
shifts →
7) For the endothermic reaction: 2SO3(g) ⇄ 2SO2(g) + O2(g)
indicate the direction the equilibrium will shift for each of the following cases.
a) Concentration of SO3 is increased.
shifts →
b) Concentration of O2 is increased.
shifts ←
c) Some SO2 is removed.
shifts →
d) The temperature is lowered.
shifts ←
e) The pressure decreases.
shifts →
f) The volume of the container gets smaller.
shifts ←
g) A catalyst is added.
no shift
8) For the reaction: N2(g) + 6HCl(g) ⇄ 2NH3(g) + 3Cl2(g); ΔH = +461 kJ
Indicate what happens to [HCl] if the following changes occur.
a) More N2 is added.
[HCl] ↓
b) Some NH3 is removed.
[HCl] ↓
c) The temperature is increased.
[HCl] ↓
d) The pressure is lowered.
[HCl] ↑
e) The volume of the container is decreased.
[HCl] ↓
f) The total pressure of the system is increased by adding He(g). no change
g) A catalyst is added.
no change
9) For the reaction: 2C2H2(g) + 5O2(g) ⇄ 4CO2(g) + 2H2O(l) + heat
Indicate what happens to the amount of CO 2 if the following changes occur.
a) Some C2H2 is removed.
[CO2] ↓
b) Some H2O is added.
no change
c) The temperature is increased.
[CO2] ↓
d) The pressure is increased.
[CO2] ↑
e) The volume of the container doubles in size.
[CO2] ↓
f) Some Ar gas is added to the container.
no change
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