MCQ
Benzene undergoes substitution reaction more easily than addition because:
- AIt has a cyclic structure
- BIt has three double bonds
- CIt has six hydrogen atoms
- ✓Of resonance
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

[Given : Atomic mass of $H =1, C =12, N =14, O =16, S =32, Cl =35$ ]
$(A)$ Upon heating, $H _3 PO _3$ undergoes disproportionation reaction to produce $H _3 PO _4$ and $PH _3$.
$(B)$ While $H _3 PO _3$ can act as reducing agent, $H _3 PO _4$ cannot.
$(C)$ $H _3 PO _3$ is a monobasic acid.
$(D)$ The $H$ atom of $P - H$ bond in $H _3 PO _3$ is not ionizable in water.