Multiple Choice QuestionsThe degree of unsaturation of C6H6 and butyne-2 respectively are
6 and 3
6 and 2
2 and 6
4 and 2
Among the following alkenes, which one is ,the most stable?
CH2=CH2
CH3-CH=CH2
CH3-CH=CH-CH3
(CH3)2C=C(CH3)2
In acetylene molecule, the two carbon atoms are linked by
one sigma-bond and two pi-bonds
two sigma-bonds and one pi-bond
three sigma-bonds
three pi-bonds
Pick out the alkane which differs from the other members of the group
2,2-dimethyl propane
pentane
2-methyl butane
2,2-dimethyl butane
On treating a mixture of two alkyl halides with sodium metal in dry ether, 2-methyl propane was obtained. The alkyl halides are
2-chloropropane and chloromethane
2-chloropropane and chloroethane
chloromethane and chloroethane
chloromethane and 1-chloropropane
Which one of the following statements about benzyl chloride is incorrect?
It is less reactive than alkyl halides
It can be oxidised to benzaldehyde by boiling with copper nitrate solution
It is a lachrymatory liquid and answers Beilstein's test
It gives a white precipitate with alcoholic silver nitrate
Which cycloalkane has the lowest heat of combustion per CH2 group?
Cyclopropane
Cyclobutane
Cyclopentane
Cyclohexane
D.
Cyclohexane
In cyclopropane the angle strain is maximum. Hence, it is highly strained molecule and consequently most unstable. The angle strain in cyclobutane is less than cyclopropane. Hence, cyclobutane is more stable. This stability mcreases upto 6 membered rings, then decreases from 7 to 11 membered rings and from the 12 membered rings onwards attains the stability of 6 membered ring. Heat of combustion is a method of measuring chemical stability. Hence, cyclohexane has the lowest heat of combustion.
A gas decolourised by KMnO4 solution but gives no precipitate with ammoniacal cuprous chloride is
ethane
methane
ethene
acetylene
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