Question

In context with beryllium, which one of the following statements is incorrect ?

• A. It is rendered passive by nitric acid
• B. It forms $B{e}_{2}C$
• C. Its hydride is electron-deficient and polymeric
• D. Its salts rarely hydrolyse

Answer 1

The correct option is D Its salts rarely hydrolyse

1. Beryllium is rendered passive by concentrated $HN{O}_3$ i.e., it does not react. This is because concentrated $HN{O}_3$ is a strong oxidising agent and it forms a very thin layer of oxide on surface of the metal, which protects it from further attack by the acid.

2. Beryllium forms carbide, $B{e}_{2}C$ by heating $BeO$ with $C$ at $1900-{2000}^{o}C$.

3. Be-Salts are highly covalent and hence are easily hydrolysed.
$BeC{l}_2+2HOH⟶Be(OH{)}_2+2HCl$

4. $(Be{H}_2{)}_n$ [Beryllium hydride] is electron deficient and is in polymeric form.

Hence, option (c) is correct.