Question
A gas $$'X'$$ is passed through water to form a saturated solution. The aqueous solution on treatment with silver nitrate gives a white precipitate. The saturated aqueous solution also dissolves magnesium ribbon with evolution of a colourless gas $$'Y'$$. Identify $$'X'\,{\text{and}}\,'Y'$$.
A.
$$X = C{O_2},Y = C{l_2}$$
B.
$$X = C{l_2},Y = C{O_2}$$
C.
$$X = C{l_2},Y = {H_2}$$
D.
$$X = {H_2},Y = C{l_2}$$
Answer :
$$X = C{l_2},Y = {H_2}$$
Solution :
Since the saturated aqueous solution of $$\left( X \right)$$ give white ppt with $$AgN{O_3},$$ so$$\left( X \right)$$ may be $$C{l_2}.$$ Hence
$$\mathop {C{l_2}}\limits_{\left( X \right)} + {H_2}O \to HOCl + HCl$$
$$HCl + AgN{O_3} \to \mathop {AgCl}\limits_{White} \downarrow + HN{O_3}$$
$$2HCl + Mg \to MgC{l_2} + \mathop {{H_2}}\limits_{\left( Y \right)} \uparrow $$