Question

For the endothermic reaction below, which change would cause the equilibrium to shift to the right? (only one answer is possible)CH4(g) + 2H2S(g) + heat ↔ CS2 (g) + 4H2 (g)(a) Decrease the concentration of hydrogen sulfide.(b) Increase the pressure on the system.(c) Increase the temperature of the system.(d) Increase the concentration of carbon disulfide.(e) Decrease the concentration of methane.

Answer 1

Increase the temperature of the system. Option C is correct

Explanations:

Given the chemical reaction below;

`CH_4(g)+2H_2S(g)+heat\rightleftarrows CS_2(g)+4H_2(g)`

The following will shift the equilibrium reaction to the left

• Increasing the concentration of the product and decreasing the concentration of the reactants (CH4 and H2S) will lead to increase in the concentration of CS2 and hydrogen gas shifting the equilibrium to the left. Hence, options A, D and E are incorrect

,

• For the pressure, increasing the pressure of the system will shift the equilibrium to the side with least number of moles. Since the total number of moles of reactant is less than that of product, hence, ,increasing the temperature of the system will shift the equilibrium to the left nullifying option B

For the temperature, you can see that the reaction is endothermic and there are more heat at the reactant than at the product, hence increasing the temperature will force the reaction to proceed towards the right (the product side).