Embibe Experts Solutions for Chapter: The s-Block Elements, Exercise 4: EXERCISE-4

Discuss the trend of the following:
(A) Thermal stability of carbonates of Group $2$ elements.
(B) The solubility and the nature of oxides of Group $2$ elements.

The $\mathrm{s}$-block elements are characterised by their larger atomic sizes, lower ionisation enthalpies, invariable $+1$ oxidation state and solubilities of their oxosalts. In the light of these features describe the nature of their oxides, halides and oxosalts.   

When a metal of group 1 was dissolved in liquid ammonia, the following observations were obtained:

(i) Blue solution was obtained initially.

(ii) On concentrating the solution, blue colour changed to bronze colour.

How do you account for the blue colour of the solution? Give the name of the product formed on keeping the solution for some time.

The stability of peroxide and superoxide of alkali metals increase as we go down the group. Explain giving reason.

When water is added to compound $\left(\mathrm{A}\right)$ of calcium, solution of compound $\left(\mathrm{B}\right)$ is formed. When carbon dioxide is passed into the solution, it turns milky due to the formation of compound $\left(\mathrm{C}\right)$. If excess of carbon dioxide is passed into the solution milkiness disappears due to the formation of compound $\left(\mathrm{D}\right)$. Identify the compounds $\mathrm{A}, \mathrm{B}, \mathrm{C}$ and $\mathrm{D}$. Explain why the milkiness disappears in the last step.

Lithium hydride can be used to prepare other useful hydrides. Beryllium hydride is one of them. Suggest a route for the preparation of beryllium hydride starting from lithium hydride. Write chemical equations involved in the process.

An element of group $2$ forms covalent oxide which is amphoteric in nature and dissolves in water to give an amphoteric hydroxide. Identify the element and write chemical reactions of the hydroxide of the element with an alkali and an acid.

Cement, the important building material is a mixture of oxides of several elements. Besides calcium, iron and sulphur, oxides of elements of which of the group(s) are present in the mixture?