A magnesium ribbon is burnt in oxygen to give a white compound $\mathrm{X}$ accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound $\mathrm{Y}$.

Write the chemical formula of $\mathrm{X}$ and $\mathrm{Y}$.

A magnesium ribbon is burnt in oxygen to give a white compound $\mathrm{X}$ accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound $\mathrm{Y}$.

Write a balanced chemical equation, when $\mathrm{X}$ is dissolved in water.

A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.

Why do silver articles turn black when kept in the open for a few days?

A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.

Name the black substance formed and give its chemical formula.

On heating blue coloured powder of copper $\left(\mathrm{II}\right)$ nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas $\mathrm{X}$ is formed.

Write a balanced chemical equation of the reaction.

On heating blue coloured powder of copper $\left(\mathrm{II}\right)$ nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas $\mathrm{X}$ is formed.

Identify the brown gas $\mathrm{X}$ evolved.

On heating blue coloured powder of copper$\left(\mathrm{II}\right)$ nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas $\mathrm{X}$ is formed.

Identify the type of reaction.

On heating blue coloured powder of copper$\left(\mathrm{II}\right)$ nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas $\mathrm{X}$ is formed.

What could be the $\mathrm{pH}$ range of aqueous solution of the gas $\mathrm{X}$?