Question

For the endothermic reaction

CaCO3 (s) <-----> CaO (s) + CO2 (g)


Le Chtelier's principle predicts that __________ will result in an increase in the number of moles of CO2 at equilibrium.



a. increasing the temperature

b. decreasing the temperature

c. increasing the pressure

d. removing some of the CaCO3(s)

e. adding more CaCO3 (s)

Answer 1

For the endothermic reaction
CaCO3 (s) <-----> CaO (s) + CO2 (g)
No . of moles of the gaseous products will be more than the reacatnts , so the volume of the products will be more .
According to the Le-Charterlier's principle ,
(1) If the temperature is raised , reaction will proced in the direction in which some heat can destroy(absorbed) so that temperature of the system remains constant.
Thus increase in temperature shifts the equilibrium in the forward direction of those reactions which proceed with absorption of heat ( endothermic reactions), and in the back ward direction of those reactions which proceed with the evolution of heat ( exothermic reactions)
(2) If the pressure is increased , reaction will takes place in a direction which will bring about lowering f pressure.This implies that the equilibrium will shifts in the direction which produces the smaller no . of gas molecules.
(3) If the concentration of reactants is increased or product is removed , the reaction will take place in the forward direaction.

Le Chtelier's principle predicts that the number of moles of CO2 at equilibrium increases if
a. increasing the temperature
e. adding more CaCO3 (s)

Answer 2

Increasing in temperature