45. A metal carbonate X on reacting with an acid gives a gas which when passed through a solution Y gives the carbonate back. On the other hand, a gas G that is obtained at anode during electrolysis of brine is passed on dry Y, it gives a compound Z, used for disinfecting drinking water. Identify X, Y, G and Z.
Steps: Carbonate + acid → CO₂. CO₂ + Ca(OH)₂ → CaCO₃ (insoluble milky). Chlorine reacts with slaked lime to give bleaching powder used as disinfectant.