Introduction:
The Haber process is an industrial method used to synthesize ammonia (NH3) from nitrogen gas (N2) and hydrogen gas (H2). It involves a reversible reaction that takes place under specific conditions of temperature and pressure. The percentage of ammonia obtained after cooling the equilibrium mixture depends on the equilibrium position of the reaction.

Explanation:
- The Haber process can be represented by the following balanced chemical equation:
N2(g) + 3H2(g) ⇌ 2NH3(g)
- According to Le Chatelier's principle, when a system at equilibrium is subjected to a change, it tends to counteract that change and establish a new equilibrium position. In the case of the Haber process, cooling the equilibrium mixture is a change that affects the position of the equilibrium.
- Cooling the equilibrium mixture shifts the equilibrium in the direction that produces more heat. Since the forward reaction is exothermic (releases heat), it will be favored by lowering the temperature.
- As a result of cooling, the equilibrium will shift towards the formation of more ammonia (NH3) to counteract the decrease in temperature. This means that the percentage of ammonia in the mixture will increase.
- The cooling does not convert all the reactants into ammonia because the reaction is reversible. At equilibrium, there will be a certain percentage of reactants and products present in the mixture.
- The correct answer is option 'D' (98 percent) because cooling the equilibrium mixture in the Haber process results in a high percentage of ammonia, but not 100 percent. The remaining percentage consists of unreacted nitrogen and hydrogen gases.
- Achieving 100 percent conversion of reactants into products is not practically feasible due to the reversibility of the reaction and the need to balance other factors such as cost, efficiency, and safety in industrial processes.

Conclusion:
Cooling the equilibrium mixture in the Haber process shifts the equilibrium towards the formation of more ammonia. This results in a high percentage of ammonia, but not 100 percent. The remaining percentage consists of unreacted nitrogen and hydrogen gases. Option 'D' (98 percent) is the correct answer.