Identify the state of hybridisation of each carbon in:
(i) `CH_(2)=CH-CH=CH_(2)`
(ii) `CH_(2)=C=CH_(2)`
(iii) `CH_(3)-C-=CH` ltBrgt (iv) `CH_(2)=CH-CHO`
(v) `HC-=C-CHO`

Explanation

(i) `overset(1)(C)H_(2)=overset(2)(C)H- overset(3)(C)H=overset(4)(C)H_(2),C_(1),C_(2),C_(3),C_(4)-` all `sp^(2)` hybridised.
(ii) `overset(1)(C)H_(2)=overset(2)(C)=overset(3)(C)H_(2),C_(1),C_(3)-sp^(2)` hybridised, `C_(2)-`sp hybridised.
(iii) `overset(3)(C)H_(3)-overset(2)(C)-=overset(1)(C)H,C_(1),C_(2)-` sp hybridised, `C_(3)sp^(3)` hybridised.
(iv) `overset(3)(C)H_(2)=overset(3)(C)H-overset(1)(C)H=O,C_(1),C_(2),C_(3)-sp^(2)` hybridised.
(iv) `overset(3)(C)H-=overset(2)(C)-overset(1)(C)H=O,C_(1)-sp^(2)` hybridised, `C_(2),C_(3)-` sp hybridised.