When green coloured crystals of a …

The salt \(X\) is likely ammonium dichromate, \((NH_4)_2Cr_2O_7\), which is orange, but it turns green when it decomposes. When heated, it undergoes a decomposition reaction to produce chromium(III) oxide (\(Cr_2O_3\)), nitrogen gas (\(N_2\)), and water vapor (\(H_2O\)). The green-colored substance is chromium(III) oxide, and the gas with a pungent smell is nitrogen dioxide (\(NO_2\)) which is usually formed due to secondary reactions. The decomposition reaction of ammonium dichromate can be represented by the following chemical equation: \[ (NH_4)_2Cr_2O_7 \rightarrow Cr_2O_3 + N_2 + 4H_2O \] During the heating process, some \(NH_3\) may be released, which can further oxidize to \(NO_2\) in the presence of heat and oxygen. So, the salt \(X\) is ammonium dichromate, \((NH_4)_2Cr_2O_7\), and the gas \(Y\) is nitrogen dioxide, \(NO_2\). Here is the full balanced chemical equation: \[ (NH_4)_2Cr_2O_7 \rightarrow Cr_2O_3 + N_2 + 4H_2O \] When considering secondary reactions for the release of \(NO_2\): \[ 4NH_3 + 7O_2 \rightarrow 4NO_2 + 6H_2O \]