Explain the following with proper reason:

$\mathrm{HF}$is not stored in glass bottles but kept in wax-lined bottles.

Explain the following with proper reason:

$\mathrm{HF}$has a greater electronegativity difference and more ionic character than $\mathrm{HCl}$, $\mathrm{HBr}$and $\mathrm{HI}$but it is the weakest acid.

Fill in the blanks:

Among halogen acids (hydrogen halides) $\dots \dots \dots \dots \dots$ is the strongest reducing agent.

Fill in the blanks:

${\mathrm{H}}_2{\mathrm{SO}}_4+\mathrm{HI}\to — + — + —$

Predict the products when the following reactions are carried out:

Red lead is boiled with concentrated $\mathrm{HCI}$.

Predict the products when the following reactions are carried out

${\mathrm{SiO}}_2+\mathrm{HF}⟶$