2HCN(g) N2(g) + C2H2(g)-1.The reverse reaction rate suddenly increases. 2.C2H2 is consumed.
If N2 were added to the equilibrium mixture, the reaction would shift to the right to consume some of the additional N2. This would lead to an increase in the concentration of NO and a decrease in the concentrations of N2 and O2 until a new equilibrium is established.
More NOCl would be produced
NO and Cl2 would be consumed
Heat would be produced.
More NO would form