Question

A metal ${}^{\prime }{M}^{\prime }$ burns with dazzling brilliance in air above $1000^{\circ }C$ to give a white powder. The white powder reacts with water to form a white precipitate ${}^{\prime }{P}^{\prime }$ and a colourless gas ${}^{\prime }{G}^{\prime }$ with a characteristic smell. The metal ${}^{\prime }{M}^{\prime }$ dissolve in conc. $NaOH$ to liberate another gas ${}^{\prime }{H}^{\prime }{.}^{\prime }{H}^{\prime }$ may also be obtained on heating ${}^{\prime }{G}^{\prime }.$ Then

• A. $M=Mg$
• B. $M=Be$
• C. $P=Ca(OH{)}_2$
• D. $G=O_3$

Answer 1

Answer: (B)

$Be+Air\stackrel{T>1000^{\circ }}{\to }BeO+B{e}_3{N}_2$ (white power)
$B{e}_3{N}_2+6H_{2}O\to \underset{\text{(White precipitate)}}{3Be(OH{)}_2}+\underset{\text{(Colourless gas)}}{2N{H}_3}$