Question

Which of the following statements is not true for both B and Al?

• A. They burn in oxygen to give oxides at high temperature
• B. Their halides are Lewis acids
• C. They combine with nitrogen to form nitrides
• D. They react with HCl to form chlorides

Answer 1

Answer: (D)

Boron is not attacked by HCl; whilst Al reacts with HCl to from $AlCl_{3}$ and $H_{2}\left(g\right)$ .
A. $4B+3O_{2} \rightarrow 2B_{2}O_{3}$
$4Al+3O_{2} \rightarrow 2Al_{2}O_{3}$
B. Halides of both are electron deficient, therefore, act as Lewis acids.
C. $2B+N_{2} \rightarrow 2BN$
$2Al+N_{2} \rightarrow 2AlN$