In the following questions a statement of Assertion (A) followed by a statement of
Reason (R) is given. Choose the correct option out of the choices given below each question.
Assertion (A): All the carbon atoms in H2C = C = CH2 are sp2 hybridised
Reason (R): In this molecule all the carbon atoms are attached to each other by double bonds.
(i) Both A and R are correct and R is the correct explanation of A.
(ii) Both A and R are correct but R is not the correct explanation of A.
(iii) Both A and R are not correct.
(iv) A is not correct but R is correct.
In H2C = C = CH2 , both the terminal carbon atoms are sp2 hybridised, whereas the carbon atom present in the centre of the molecule is forming only two sigma bonds, as the sigma bond is used for calculating the hybridisation. Hence the hybridisation of the central carbon is sp.
So, the assertion is wrong.
Now, considering the Reason, In this molecule all the carbon atoms are attached to each other by double bonds, is true. Hence option (iv) is correct.