Hydrofluoric acid $(HF)$ cannot be stored in glass bottles because it reacts with glass to form which of the following?

Which is the best reducing agent?

In the dark,which of the following reacts with hydrogen?

Fluorine is a stronger oxidising agent than chlorine because :
$(a)$ $F-F$ bond has a low enthalpy of dissociation.
$(b)$ Fluoride ion $(F^{-})$ has high hydration enthalpy.
$(c)$ Electron gain enthalpy of fluorine is less negative than chlorine.
$(d)$ Fluorine has a very small size.
Choose the most appropriate answer from the options given :

Hydrolysis of $NCl_3$ gives $NH_3$ and $X$. Which of the following is $X$?

Draw the molecular formula and structure of perbromic acid.