Compound \( A \) reacts with \( \mathrm{NH_4Cl} \) and forms a compound \( B \). Compound \( B \) reacts with \( \mathrm{H_2O} \) and excess of \( \mathrm{CO_2} \) to form compound \( C \) which on passing through or reaction with saturated \( \mathrm{NaCl} \) solution forms sodium hydrogen carbonate. Compound \( A \), \( B \) and \( C \), are respectively.