1
Question
Arrange the following alkanes in decreasing order of their heats of combustion.
(i) CH3−CH3|C|CH3−CH3(Neo−pentane)
(ii) CH3−CH|CH3−CH2−CH3(Iso−pentane)
(iii)CH3−CH2−CH2−CH2−CH3(n−pentane)
Arrange the following alkanes in decreasing order of their heats of combustion.
(i) CH3−CH3|C|CH3−CH3(Neo−pentane)
(ii) CH3−CH|CH3−CH2−CH3(Iso−pentane)
(iii)CH3−CH2−CH2−CH2−CH3(n−pentane)
Open in App
Solution
The correct option is C (iii) > (ii) > (i)
CH3H3C−|C|−CH3 CH3−CH|−CH2−CH3 CH3CH2CH2CH2−CH3 CH3 CH3 Neopentane(i) Iso−pentane(ii) n−pentane(iii)
We know that alkanes that are more branched, have less heat of combustion than a less branch one. Thus here heat of combustion order will be:n−pentane(iii)>isopentane(ii)>Neopentane(i).
Because here Neopentane is more branched than isopentane which is again more branched than n−pentane.
CH3
H3C−|C|−CH3 CH3−CH|−CH2−CH3 CH3CH2CH2CH2−CH3 CH3 CH3
Neopentane(i) Iso−pentane(ii) n−pentane(iii)
We know that alkanes that are more branched, have less heat of combustion than a less branch one. Thus here heat of combustion order will be:
n−pentane(iii)>isopentane(ii)>Neopentane(i).
Because here Neopentane is more branched than isopentane which is again more branched than n−pentane.
Suggest Corrections
0
Similar questions
View More
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program
