Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
$(a)$ Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at $773 \ K$ to form ammonia gas.
$(b)$ Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water.

When $Zn$ metal is treated with a dilute solution of a strong acid,a gas is evolved,which is utilised in the hydrogenation of oil. Name the gas evolved. Write the chemical equation of the reaction involved and also write a test to detect the gas formed.

What are the substances added to a catalyst to increase its efficiency called?

By which method/process is ammonia gas manufactured?

Which of the following are exothermic processes?
$(i)$ Reaction of water with quicklime
$(ii)$ Dilution of an acid
$(iii)$ Evaporation of water
$(iv)$ Sublimation of camphor (crystals)

Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?
$(i)$ It is an endothermic reaction
$(ii)$ It is an exothermic reaction
$(iii)$ The $pH$ of the resulting solution will be more than seven
$(iv)$ The $pH$ of the resulting solution will be less than seven