Question

Assertion (A) : Silica is soluble in $HF$.
Reason ( R ): $Si{O}_2+4HF⟶Si{F}_4+2H_{2}O$
$Si{F}_4+2HF⟶H_{2}Si{F}_6$

• A. A and R both are correct and R is the correct explanation of A.
• B. A and R both are correct but R is not the correct explanation of A.
• C. A and R both are incorrect.
• D. A is correct while R is incorrect.

Answer 1

Answer: (B)

Silica is soluble in $HF$.
$Si{O}_2$ reacts with HF to give $Si{F}_4$ if $HF$ is present in excess it gives $H_{2}Si{F}_6$.
$Si{O}_2+4HF⟶Si{F}_4+2H_{2}O$
$Si{F}_4+2HF⟶H_{2}Si{F}_6$
hydrofluoro silicic acid