Dilute aqueous solution of $.......$ acid is used as an antibiotic.

Anhydrous $AlCl_3$ cannot be obtained from which of the following reactions?

In a molecule of pyrophosphoric acid $(H_4P_2O_7)$,the number of $P-OH$,$P=O$ and $P-O-P$ bonds/moiety(ies) respectively are:

Which one of the following forms a basic oxide?

What are the freezing and boiling points of ammonia $(NH_3)$?

The correct orders among the following are
$A$. Atomic radius $: B < Al < Ga < In < Tl$
$B$. Electronegativity $: Al < Ga < In < Tl < B$
$C$. Density $: Tl < In < Ga < Al < B$
$D$. $1^{st}$ Ionisation Energy $: In < Al < Ga < Tl < B$
Choose the correct answer from the options given below $:$