Question

A mixture of nitrogen and hydrogen in the ratio of 1 : 3 reaches at equilibrium with ammonia

Answer 1

   N2+3H2=======>2NH3.

   At the start of the reaction the Pressure was'P'.

   Suppose if we consider 1 mole of N2 gas and 3 moles of H2 gas was present in the beginning.(4 moles)

   After the completion of 50% of the Reaction, 0.5 mole of N2, 1.5 mole of H2 and 1 mole of NH3 will be present.

   So the initial 4 moles will be now (0.5+1.5+1)=3 moles will be present at the equilibrium after the completion of 50% reaction. So the Pressure at equilibrium will be 3/4 x P. = 0.75 P.

   The partial pressure of Ammonia = 0.75 x (1/3) x P

   = 0.25P