A chloride salt solution acidified with dil. \( \mathrm{HNO_3} \) gives a curdy white precipitate, \( [A] \), on addition of \( \mathrm{AgNO_3} \). \( [A] \) on treatment with \( \mathrm{NH_4OH} \) gives a clear solution, \( B \). \( A \) and \( B \) are respectively,
