KVPY SX SB Exam 2015 Question Paper

A metal (X) dissolves both in dilute HCl and dilute NaOH to liberate H${}_2$. Addition of NH${}_4$Cl and excess NH${}_4$OH to an HCl solution of X produces Y as a precipitate. Y is also produced by adding NH${}_4$Cl to the NaOH solution of X. The species X and Y, respectively, are