Question

$Si{O}_2$ reacts with :

• A. $N{a}_{2}C{O}_3$
• B. $C{O}_2$
• C. $HF$
• D. $HCl$

Answer 1

Answer: (A), (C)

$HF$

Silica is very unreactive in its normal. It is not attacked by various acids and halides. It doesnot react with $C{O}_2$ and $HCl$.
However, it react with hydrofluoric acid to form hexafluorosilicic acid.
$Si{O}_2+4HF\to Si{F}_4+2H_{2}O$
$Si{F}_4+2HF\to H_{2}Si{F}_6$

When silica is mixed with solid sodium carbonate and melted, sodium silicate is formed. This reaction is the basic reaction in the manufacture of glass.
$Si{O}_2+N{a}_{2}C{O}_3\to N{a}_{2}Si{O}_3+C{O}_2$
So, option A and C are correct.