Question

17) In a chemistry laboratory, a research scholar while conducting an experiment, observed at a certain step that yellow coloured gas (X) was released and it has been found to be poisonous. This was later made to react with highly reactive metal (Y). A new compound (Z) was formed which was used for preservation of fish, meat, and pickles. Professor asked him to identify X, Y, and Z.

Answer 1

• X is a yellow-colored gas and is poisonous, hence this gas is Chlorine $\left({\mathrm{Cl}}_2\right)$
• ‘Y’ is a highly reactive metal, hence it should be Sodium $\left(\mathrm{Na}\right)$ because is kept in kerosene because of its reactivity.
• Hence when Sodium metal and Chlorine gas react it leads to the formation of 2 moles of sodium chloride (Z)

$$\begin{gathered} 2\mathrm{Na}+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to 2\mathrm{NaCl} \\ \left(\mathrm{sodium}\right)\left(\mathrm{chlorine}\right)(\mathrm{sodium}\mathrm{chloride}) \end{gathered}$$

• Hence Sodium chloride is used in the preservation of pickles.