Question

Consider the following equilibrium for which H = 664.38:

N2(g) + 2 H2O(g) 2 NO(g) + 2 H2(g)

How will each of the following changes affect an equilibrium mixture of the 4 gases in this reaction?

(a) NO(g) is added to the system.

(b) The reaction mixture is heated.

(c) The volume of the reaction vessel is reduced by 50%.

(d) A catalyst is added to the reaction mixture.

(e) The total pressure of the system is increased by adding a noble gas.

(f) H2O(g) is removed from the system.

The answer choice options for each are:

The equilibrium will not shift

The equilibrium will shift towards product but Keq will not change,

The equilibrium will shift towards reactant but Keq will not change

The equilibrium will shift towards product and Keq will increase

The equilibrium will shift towards reactant and Keq will decrease

Answer 1

N2ng + 2 H209 2 2N0g) + 2H29) 01=+664.38 a) . Noig is added to the System ,' According to Lechatelier principle, the' equilibrium position will move so that the concentration of noce decreases again by reacting it with H2(g) to form more Nag and H₂O The equilibrium moves to the left towards reactant and keq will increase. Keg a [no]? [4₂]² [Na] [H20]? b) The reaction mixture is heated, Here, OH = + ve il., the reaction is endothermic. If the reaction mixture is heated, then there is an increas in temperature, the position of equiliboium Shifts in a direction so as to decrease the temperature. Here, the equiliborum Shifts towards products and there is no change in Keqi c) The volume of the reaction vessel is reduced by 50%. When there is a decrease in volume, the equilibrium will shift towards the side of the reaction with fewer moles. In this case, Only 3 moles of reactants are present and hence the equilibrium Shifts- towards reactants and Keq will not change.

d) A Catalyst is added to the reaction mixtue. Aclding a catalyst makes no difference to the position equilibrium, and Le Chatelier's principle does not apply. This is because a catalyst speeds up the forward and backunud reaction to the same extent, and it doesnot affect the relative dates of two reactions, it cannot affect the position of equilibrium. e) The total pressure of the System is increased by adding a noble goy. 1. When the pressure of the system increases by adding an inext gas into a gas phase equilibrium at constant volume does not result in a shift. This is because this addition of a non-reactive gas does not change the partial pressures of the other gases in the containere The total pressure does not have any effect on the equilibrium constant. f) H20 g) is removed from the System. According to Lechatelier's principle when concentration of 120g) is removed i-e., decreased, the position of equilibrium will move so that the concentration of H2O 0) increases again. More Norg, and H29) will react to replace H₂Og, that has been removed. The position of equilibrium moves to the left: il., the equilibrium will shift towards reactants and Keq will increase.