Question

In the following reaction, will the [H2] increase or decrease when equilibrium is reestablished after these stresses are applied?

N2 (g) + 3 H2 (g) ←--> 2 NH3 (g) + 22 kJ

NH3(g) is added ________
N2(g) is removed ________

2. Note reaction: 2 NO (g) + H2 (g)<---->N2 O (g) + H2 O (g) + 36 kJ
In which direction, left or right, will the equilibrium shift if the following changes are made?
NO is added ________
H2 is removed ________
N2O is added ________
H2 is removed ________

3. In this reaction: CO2 (g) + H2 (g) + heat ←-->CO (g) + H2 O (g)
In which direction will the equilibrium shift if these changes are made?
CO is added ________
CO2 is added ________
H2 is removed ________

4. In this reaction: 2 NO (g) + H2 (g) ←--->N2 O (g) + H2 O (g) + heat
What will happen to the [H2O] when equilibrium is reestablished after these stresses are applied?
NO is added ________
N2O is removed _________

Answer 1

1. (i) H₂ will decrease

(ii) H₂ will increase

2. (i) Shift right

(ii) Shift left

(iii) Shift left

(iv) Shift left

3. (i) Shift left

(ii) Shift right

(iii) Shift left

4. (i) H₂O will increase

(ii) H₂O will increase

Step-by-step explanation:

1. For the reaction, N₂ (g) + 3H₂ (g) ↔ 2NH₃ (g) + 22 kJ

(i) When the NH₃ is removed, the concentration of the products is reduced favoring the consumption of further reactants hence the H₂ will decrease

(ii) When N₂ is removed, N₂ will become the limiting reactant resulting in the presence of excess H₂, hence H₂ will increase

2. 2NO (g) + H₂ (g) ↔ N₂O (g) + H₂O (g) 36 kJ

(i) When NO is added, it will favor the increase of the reaction and the equilibrium will shift to the right

(ii) H₂ is removed, it will favor the decomposition of the products hence the equilibrium will shift to the left

(iii) When N₂O is added, it will cause the increase in the partial pressure of the products which will result in the increase in the partial pressures of the reactants to compensate, hence the equilibrium will shift to the left

(iv) When H₂ is removed it will cause the equilibrium to shift left as more products will decompose to form the balance H₂

3. For the reaction;

CO₂ (g) + H₂ (g) + heat ↔ CO (g) + H₂O (g)

(i) When CO is added, there will be an excess partial pressure of the products and the equilibrium will shift left

(ii) When CO₂ is added, there will be an excess partial pressure of the reactants which will favor the formation of the products and the equilibrium will shift right

(iii) When H₂ is removed, there will be an decrease in the partial pressure and concentration of the reactants which will favor the decomposition of the products to balance up the partial pressures of the reactant and the equilibrium will shift left

4. In the reaction 2NO (g) + H₂ (g) ↔ N₂O (g) + H₂O (g) + heat

(i) When NO is added, the concentration of the reactants will increase, hence increasing the likelihood of the formation of more products and the equilibrium will shift to the right and H₂O will increase

(ii) When N₂O is removed, the partial pressure and concentration of the products will reduce hence to balance up the partial pressures of the reacting mixture, more products will be formed and H₂O will increase.