Eduprobe
Question:
For the reversible reaction: N2(g) + 3H2(g) ⇌ 2NH3(g) + heat. The equilibrium shifts in the forward direction:
by increasing the concentration of NH3(g)
by decreasing the concentrations of N2(g) and H2(g)
by increasing pressure and decreasing temperature
by decreasing the pressure
Solution:
For the reversible reaction: N2(g) + 3H2(g) ⇌ 2NH3(g) + heat. The equilibrium shifts in the forward direction by increasing pressure and decreasing temperature. According to Le Chatelier's principle, when equilibrium is disturbed by a change, the system will try to nullify the effect of change to restore the equilibrium. Thus, when pressure is increased, the equilibrium will shift in a direction in which there is a decrease in the number of moles of gaseous substances. This will nullify the effect of increased pressure. This happens in the forward direction. Similarly, for an exothermic reaction, when the temperature is decreased, the equilibrium shifts in the forward direction.