Question

Which of the following reactions proceed at low pressure ?

• A. $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$
  
• B. $H_2\left(g\right)+I_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$
• C. $PC{l}_5\left(g\right)\rightleftharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$
  
• D. $N_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2NO\left(g\right)$
  

Answer 1

The correct option is C $PC{l}_5\left(g\right)\rightleftharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$


At low pressure,according to the Le chatelier's principle, reaction will proceed in the direction which has more no. of moles. The number of moles in product side is greater than reactants side. This is the favourable only for the reaction , $PC{l}_5\left(g\right)\rightleftharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$ among the given reactions. So, that reaction will proceed at low pressure.