Question

Point out the incorrect statements regarding Be (Group IIA)
A. It forms an ionic carbide
B. Its carbonates decompose on heating
C. Its halides are covalent
D. It is easily attacked by water

Answer 1

Hint: Beryllium is a metal belonging to the group-2 periodic table. It is the first element of the group due to which it has some of its anomalous characteristics as compared to other metals of the same group.

Complete Step by Step Answer:
Beryllium is a unique metal but has various applications.

From the given options we have to find the incorrect statement about Be.
A. It forms an ionic carbide
Metals from Mg to Ba or their oxides, when heated with carbon, give carbides.
Beryllium forms an ionic carbide and the reaction happens as follows:-
\[{\rm{2BeO + 3C}} \to {\rm{B}}{{\rm{e}}_{\rm{2}}}{\rm{C + 2CO}}\]
So, A is incorrect.

B. Its carbonates decompose on heating
Carbonates of Be undergo decomposition on heating yielding carbon dioxide and beryllium oxide.
\[{\rm{BeC}}{{\rm{O}}_{\rm{3}}} \to {\rm{BeO + C}}{{\rm{O}}_{\rm{2}}}\]
This carbonate is unstable and can be maintained only in the atmosphere of carbon dioxide.
So, B is incorrect.

C. Its halides are covalent
Except for beryllium halides, all other halides of alkaline earth metals are ionic.
Beryllium halides are covalent because the beryllium cation is small in size as compared to the halide anions.
So, C is incorrect.

D. It is easily attacked by water
Beryllium and water react to yield beryllium oxide, beryllium hydroxide and hydrogen gas. This reaction happens in a boiling solution.
\[{\rm{2Be + 3}}{{\rm{H}}_{\rm{2}}}{\rm{O}} \to {\rm{BeO + Be}}{\left( {{\rm{OH}}} \right)_{\rm{2}}}{\rm{ + 2}}{{\rm{H}}_{\rm{2}}}\]
​So, D is the correct statement.
So, option D is correct.

Note: Beryllium is utilised for nuclear reactions. It is also utilised in preparing alloys. The presence of a little quantity of Be in Mg lessens its combustibility. It has a huge affinity for oxygen and forms beryllium oxide in reaction with oxygen.