Question

Which of the following is false for Silica Gel?

• A. Can be prepared by dehydrating silicic acid.
• B. Can be prepared by action of water on silicon tetraflouride
• C. Used as a catalyst in petroleum industry.
• D. None of these

Answer 1

The correct option is D

None of these

Silica gel which is an amorphous form of silica can be prepared by:

By the action of water on silicon tetra-fluoride or tetrachloride

$SiC{l}_4+4H_{2}O\to Si{O}_2.2H_{2}O+4HCl$

Silica gel

By the action of acid (HCl) on soluble sodium silicate white gelatinous precipitate of silica gel is obtained.

$N{a}_{2}Si{O}_3+2HCl+H_{2}O\to Si{O}_2.2H_{2}O+2NaCl$

By dehydrating silicic acid

$Si(OH{)}_{4\left(aq\right)}\to Si{O}_2.2H_{2}O$

Silicic acid

Silica gel is amorphous and very porous. It contains about 4% water and is used

As a catalyst in petroleum industry and as an absorbent in column chromatography.