Single Choice

The correct order of heat of combustion for following alkadienes is:

A(c) $$<$$ (b) $$<$$ (a)
B(a) $$<$$ (b) $$<$$ (c)
Correct Answer
C(b) $$<$$ (c) $$<$$ (a)
D(a) $$<$$ (c) $$<$$ (b)

Solution

Heat of combustion $$\propto\dfrac{1}{stability}$$

Trans is more stable than cis.

Both are trans in image $$a$$.
$$\therefore$$ It is most stable.

One cis and one trans in image $$b$$
It is less stable.

Both are cis in image $$c$$
$$\therefore$$ It is least stable.

The order of stability: $$a > b > c$$

The order of heat of combustion: $$ a < b < c$$

Hence, option $$B$$ is correct.

SIMILAR QUESTIONS

Haloalkanes and Haloarenes

The possible structure of (A) is

Haloalkanes and Haloarenes

Write notes on cis-trans isomerism with suitable example.

Haloalkanes and Haloarenes

Write steps to bring about the following transformation in not more than two steps: tert-butyl bromide to isobutyl bromide

Haloalkanes and Haloarenes

Trans-forms are ....... stable than cis-forms.

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