NCERT Solutions for Chapter: Hydrogen, Exercise 1: Long Answer Type

How can ${\mathrm{D}}_2\mathrm{O}$ be prepared from water? Mention the physical properties in which ${\mathrm{D}}_2\mathrm{O}$ differs from ${\mathrm{H}}_2\mathrm{O}$. Give at least three reactions of ${\mathrm{D}}_2\mathrm{O}$ showing the exchange of hydrogen with deuterium.

How will you concentrate ${\mathrm{H}}_2{\mathrm{O}}_2$? Show differences between structures of ${\mathrm{H}}_2{\mathrm{O}}_2$ and ${\mathrm{H}}_2\mathrm{O}$ by drawing their spatial structures. Also mention three important uses of ${\mathrm{H}}_2{\mathrm{O}}_2$.

Give a method for the manufacture of hydrogen peroxide and explain the reactions involved therein.

Illustrate oxidising, reducing, and acidic properties of hydrogen peroxide with equations.

What mass of hydrogen peroxide will be present in $2$ litres of a $5$ molar solution? Calculate the mass of oxygen which will be liberated by the decomposition of $200 \mathrm{mL}$ of this solution.

A colourless liquid $‘\mathrm{A}’$ contains $\mathrm{H}$ and $\mathrm{O}$ elements only. It decomposes slowly on exposure to light. It is stabilised by mixing urea to store in the presence of light.

(i) Suggest possible structure of $\mathrm{A}$.

(ii) Write chemical equations for its decomposition reaction in light.

An ionic hydride of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine. This is used in the synthesis of other useful hydrides. Write the formula of this hydride. Write its reaction with ${\mathrm{Al}}_2{\mathrm{Cl}}_6$.

Sodium forms a crystalline ionic solid with dihydrogen. The solid is non-volatile and non-conducting in nature. It reacts violently with water to produce dihydrogen gas. Write the formula of this compound and its reaction with water. What will happen on electrolysis of the melt of this solid.