Question

Consider the following reaction:

PCl5 (g)⇄ PCl3 (g) + Cl2 (g) ΔH = 87.9 kJ/reaction

For each of the following changes, indicate whether the reaction will proceed towards products, towards reactants, or have no net reaction to reestablish equilibrium.

a. ___________ Temperature is increased

b. ___________ The pressure is increased by decreasing the volume.

c. ___________ The pressure is decreased by removing some PCl 5 (g)

d. ___________ The pressure is increased by adding N2(g)

e. ___________ Cl2(g) is removed

f. ____________ The temperature is increased and the volume of the vessel is increased simultaneously.

Answer 1

a) since it is an endothermic reaction, so according to le chatlier's principle on increasing the temperature reaction will go forward towards product

b) on increasing the pressure by decreasing volume, the equilibrium will try to re establish by going towards where there are less moles of gases so pressure can again goes to equilibrium. Since reactant has less gaseous molecules so reaction will go backward towards reactant

C) since reactant is removed, so according to le chatlier principle, reaction will go backward so that equilibrium.can be establish again by forming reactant.

D) when a inert gas is added at constant volume there is no change in equilibrium

E) on removing cl2, reaction will go forward so that Cl2 can be form and equilibrium can re establish

F) Reaction will go forward towards product as increasing temperature of an endothetmic reaction makes the reaction going forward . While on increasing volume, pressure will be decreased, as a result reaction will go where there are more moles of gases that is towards product. Thus overall effect will be that reaction will go forward.