Question

28. X and Y are gases at room temperature. X is less reactive and is used to preserve food material, while Y is required for combustion. Metal M gets corroded when it combines with Y in the presence of Z. An atom of M possesses 14 electrons in the second last shell and N is the last shell. Identify X, Y, Z and M.

Answer 1

Part 1: Identifying X and Y:

• It is given that X is a gas and is less reactive and used to preserve food materials. So X should be Nitrogen$\left({\mathrm{N}}_2\right)$.
• It is also given that Y is a gas and is required for combustion. So Y should be Oxygen$\left({\mathrm{O}}_2\right)$.

Part 2: Identifying M and Z:

• It is given that metal M has 14 electrons in the second last shell and N is the last shell. So metal should be Iron $\left(\mathrm{Fe}\right)$ as it has 14 electrons in its second last shell.
• Iron gets corroded when it combines with oxygen in the presence of water vapor present in the air and forms a hydrated Iron oxide $({\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O})$ which is known as rust. This process is called rusting of iron.

Hence,

• X is Nitrogen.
• Y is Oxygen.
• Z is water vapor.
• M is Iron