Answer to Question #169450 in Chemistry for Phyroe

Question

Predict the effect of raising the temperature upon each of the following gaseous equilibria:

(a) 2NO + O2⇌2NO2 + heat

(b) H2 + I2 + heat⇌2HI

(c) 2SO2 + O2⇌2SO3 + heat

(d) N2 +O2 + heat⇌2NO

(e) CO + H2O⇌CO2 + H2 + heat

Answer 1

Solution:

According to the Le Chatelier's principle:

• If the temperature is increased the equilibrium will shift to favour the reaction which will reduce the temperature. The endothermic reaction is favoured.

Hence,

(a)

2NO + O₂ ⇌ 2NO₂ + heat

or:

2NO + O₂ ⇌ 2NO₂, —△H (exothermic reaction)

The reverse reaction is endothermic, so the reverse reaction is favoured.

Increasing the temperature will shift the equilibrium to the left (←).

(b)

H₂ + I₂ + heat ⇌ 2HI

or:

H₂ + I₂ ⇌ 2HI, +△H (endothermic reaction)

The forward reaction is endothermic, so the forward reaction is favoured.

Increasing the temperature will shift the equilibrium to the right (→).

(c)

2SO₂ + O₂ ⇌ 2SO₃ + heat

or:

2SO₂ + O₂ ⇌ 2SO₃, —△H (exothermic reaction)

The reverse reaction is endothermic, so the reverse reaction is favoured.

Increasing the temperature will shift the equilibrium to the left (←).

(d)

N₂ + O₂ + heat ⇌ 2NO

or:

N₂ + O₂ ⇌ 2NO, +△H (endothermic reaction)

The forward reaction is endothermic, so the forward reaction is favoured.

Increasing the temperature will shift the equilibrium to the right (→).

(e)

CO + H₂O ⇌ CO₂ + H₂ + heat

or:

CO + H₂O ⇌ CO₂ + H₂, —△H (exothermic reaction)

The reverse reaction is endothermic, so the reverse reaction is favoured.

Increasing the temperature will shift the equilibrium to the left (←).