Question

Silicareacts with hot solution of NaOH forming

• A.
• B.
• C.
• D.

Answer 1

The correct option is

C

$N{a}_{2}Si{O}_3$

$Si{O}_2+4NaOH\to N{a}_{2}Si{O}_3+H_2$

Silica is not much soluble in acidic solutions. Silica is slightly acidic so it reacts with strong bases like NaOH and KOH. This reaction is used in furnaces to purify ores of other metals in which silica impurity is present. Silica reacts with NaOH at very high temperatures around 9000C to form sodium silicate slag.

This reaction is used in many places for the removal of silica impurities. This slag floats on the surface of the ore and thus can easily be separated from purified ore.

So, the correct answer is “Option A”.