Final answer:
The gas liberated at the anode during electrolysis of brine is chlorine (Cl₂). When passed through slaked lime, it forms calcium hypochlorite (Ca(OCl)₂), which is used for disinfecting water.
Step-by-step explanation:
During the electrolysis of brine, which is an aqueous solution of sodium chloride (NaCl), the gas '‘G’ liberated at the anode is chlorine gas, denoted as Cl₂. When chlorine gas is passed through slaked lime, it reacts to form calcium hypochlorite, which is denoted by the chemical formula Ca(OCl)₂. Calcium hypochlorite is commonly used for disinfecting drinking water.
The overall reaction at the anode during the electrolysis of brine can be represented as:
2Cl⁻(aq) → Cl₂(g) + 2e⁻
When chlorine gas (‘G') is passed through slaked lime, also known as calcium hydroxide [Ca(OH)₂], the following reaction occurs to form calcium hypochlorite (‘C'):
Cl₂(g) + Ca(OH)₂ → Ca(OCl)₂ + H₂O