equilibrium concept
Chemical equilibrium is a state in which the rate of the forward reaction _________ to the rate of the backward reaction
equals
2SO2(g) + O2(g) ⇋ 2SO3(g)
[SO3]2/[SO2]2[O2]
An equilibrium mixture is analyzed and found to contain 0.62 mol dm-3 N2, 0.50 mol dm-3 H2, and 0.24 mol dm-3 NH3.
What is Kc for the following reaction?
N2(g) + 3H2(g) ⇋ 2NH3(g)
0.74
For the following equilibria would you increase or decrease the temperature to force the reaction in the forward direction?
H2(g) + CO2(g) ⇋ H2O(g) + CO(g) (delta)H = +41.0 kJ
increase
In some reactions, the reactants form products and the product can change back into reactants. This type of reactions are called __________ reactions.
reversible
2CO(g) + O2(g) ⇋ 2CO2(g)
K= [CO2]2/[CO]2 [O2]
Given the following reaction:
PCl3 + Cl2 ⇋ PCl5 K = 96.2
At equilibrium [PCl3] is 0.5 mol dm-3, [Cl2] is 0.07 mol dm-3.
What is [PCl5]?
3.4 mol dm-3
A catalyst is added to the below reaction.
2SO2(g) + O2(g) ⇋ 2SO3 (g)
Tell how the equilibrium is affected.
no change
Chemical equilibrium is a dynamic process.
True/False
True
HCN(s) ⇋ H+(aq) + CN-(aq)
[H+][CN-]
At a given temperature, an equilibrium mixture of the reaction
2NO(g) + O2(g) ⇋ 2NO2(g)
Contains 0.090 moles NO, 0.120 moles of O2, and 0.060 moles of NO2 in a 3.00 liter container.
Calculate the value of Kc!
11
Increasing temperature to the following reaction will shift equilibrium in what direction?
4NH3(g) +5O2(g) ⇋ 4NO(g) + 6H2O(g) + heat
left
CaCO3 (s) ⇋ CaO (s) + CO2 (g) is a _____________ equilibrium.
heterogenous
3Ca2+(aq) + 2PO4 3+(aq) ⇋ Ca3(PO4)2 (s)
1/[Ca2+]3[PO4 3-]2
Given the following reaction:
H2(g) + F2(g) ⇋ 2HF (g)
At 500 0C; [H2] = [F2] = 2.10-2 mol dm-3
[HF] = 4.10-2 mol dm-3
What is Kc ?
Kc = 4
Tell how you would change a concentration in order to force the following reaction in the forward direction!
4NH3(g) +5O2(g) ⇋ 4NO(g) + 6H2O(g) + heat
decrease [NO] or [H2O]
increase [NH3] or [O2]
Balance the following equation:
BF3 + Li2SO3 ⇋ B2(SO3)3 + LiF
2BF3 + 3Li2SO3 ⇋ B2(SO3)3 + 6LiF
BF3(aq) + Li2SO3(aq) ⇋ B2(SO3)3(aq) + LiF(s)
[B2(SO3)3]/[BF3]2[Li2SO3]3
Given the following reaction:
2XY(g) ⇋ X2(g) + Y2(g)
Initial the reaction starts with 0.8 mole XY at 250 0C in a 2 dm-3 container. At equilibrium, there is 0.2 mole Y2(g).
What is Kc?
Kc = 0.25
How would you change the pressure of the system in order to shift the equilibrium of the following reaction in the reverse direction?
4NH3(g) +5O2(g) ⇋ 4NO(g) + 6H2O(g) + heat
increase pressure