Question

Identify the correct statement from the following.
(a) On commercial scale, $C{O}_2$ is obtained by heating limestone.
(b) Graphite is used as a dry lubricant.
(c) $Si{O}_2$ reacts with $HF$ but does not react with $NaOH$.
(d) In $[GeC{l}_6{]}^{2–}$, the hybridisation of central atom is $s{p}^3{d}^2$.

• A. (a) and (b) only
• B. (b) and (c) only
• C. (b) and (d) only
• D. (a), (b) and (d) only

Answer 1

The correct option is D (a), (b) and (d) only

$Si{O}_2+2NaOH\to N{a}_{2}Si{O}_3+H_{2}O$
$Si{O}_2+4HF\to \to Si{F}_4+2H_{2}O$