When zinc metal is added to dilute `H_(2)SO_(4)` solution, hydrogen is evolved. In this zinc undergoes

What happens when Zinc metal is treated with dilute H_2SO_4 ?

When zinc is added to CuSO_(4) solution, copper is precipitated. It is because of

When zinc metal is heated with caustic soda solution, the gas evolved is

When zinc 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.