Reaction A: Phenol reacts with metallic sodium to produce sodium phenoxide and hydrogen gas.
C₆H₅OH + Na → C₆H₅ONa + ½H₂.
The gas evolved is x = H₂ with molar mass 2 g/mol.
Reaction B: Benzoic acid reacts with sodium bicarbonate to produce sodium benzoate, water, and carbon dioxide.
C₆H₅COOH + NaHCO₃ → C₆H₅COONa + H₂O + CO₂.
The gas evolved is y = CO₂ with molar mass 44 g/mol.
Therefore, molar mass of x + molar mass of y = 2 + 44 = 46.
