Answer to Question #60817 in Physical Chemistry for ashok

Question

For the reaction N2+3H2 2 NH3, ΔH is negative. What will be effect on the product if
temperature is lowered and pressure is raised? Explain.

Answer 1

Negative enthalpy change says that the reaction is exothermic, the heat is releasing during the reaction with temperature elevation. The amounts of gaseous reactants are greater than the amounts of gaseous products, therefore, at constant volume, the pressure will decrease. According to Le Chatelier’s Principle, the position of dynamic equilibrium shifts to counteract the changes occurring due to chemical reactions.
If the temperature is lowered, it counteracts the temperature elevation due to chemical reaction shifting the equilibrium to the product side.
If pressure is raised, it counteracts the pressure lowering due to chemical reaction shifting the equilibrium to the product side.