Consider the reaction: Heat + Cl2 (g) + 2O2 (g) = 2 ClO2 (g) Based on Le Chateli
ID: 927135 • Letter: C
Question
Consider the reaction: Heat + Cl2 (g) + 2O2 (g) = 2 ClO2 (g)
Based on Le Chatelier’s principle, predict whether each of the following changes should favor the forward or the reverse direction. Just provide simple answer of forward or reverse - NO Detail needed. Thank you.
removal of O2 ______________
addition ofO2 _______________
an increase of the size of the container____________
an increase in temperature ______________
an increase in pressure _______________
a decrease in pressure ________________
Explanation / Answer
According to the Le-Charterlier's principle,
(1) If the temperature is raised, reaction will proceed 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 direction. If the concentration of reactants decreases or increasing the concentration of products the reaction will take place in the backward direction.
(4) Catalyst speeds up both forward & backward reactions to the same extent but does not have any effect on Equilibrium point.
(5)---> When the no. of moles of reactants & products are same the addition of inert gas has no effect
----> for a reaction at constant pressure ,addition of an inert gas will shifts the equilibrium in the direction in
which there is increase in the no . of moles of the gases
In the given problem the reaction is Heat + Cl2 (g) + 2O2 (g) ----> 2 ClO2 (g)
That means the reaction is endothermic reaction.
This can be effected as follows ......
removal of O2 ----> decreasing the concentration of reactants so it favours backward direction.
addition of O2 ----> increasing the concentration of reactants so it favours forward direction.
an increase of the size of the container -----> no effect
an increase in temperature ---> for endothermic reactions increase of temperature favours forward direction
an increase in pressure ----> Cl2 (g) + 2O2 (g) ----> 2 ClO2 (g)
3 moles 2 moles
So the number of moles decreasing in forward direction so increase of pressure takes place
Therefore increase of pressure favours forward direction.
a decrease in pressure ----> decrease of pressure favours backward direction.