Hydrocarbons - Online Test
Q1. Which of these fuels given below is not a hydrocarbon?
Answer : Option B
Explaination / Solution:
Because hydrocarbons contain both C and H and hence Hydrogen is not a hydrocarbon. .
Q2. Saturated Hydrocarbons contain
Answer : Option C
Explaination / Solution:
saturated hydrocarbons are the compounds in which there is a single bond between the carbon atoms.They are also called alkanes and have the general formula CnH2n+2
Q3. in cycloalkanes carbon atoms form
Answer : Option D
Explaination / Solution:
Cycloalkanes contain single bond between the carbon atoms,they form ring structures and have the general formula CnH2n
Q4. Which of these is not a characteristic of aromatic Hydrocarbons?
Answer : Option B
Explaination / Solution:
aromatic hydrocarbon are not open chained. They are ring structures.they contain one or more benzene rings either fused or isolated in their molecules.
Q5.
The number of chain isomers of are
Answer : Option A
Explaination / Solution:
n-pentane CH3CH2CH2CH2CH3
2-Methylbutane CH3CH(CH3)CH2CH3
2,2-Dimethylpropane CH3CH(CH3)2CH3
Q6. n the Wurtz reaction method of preparation of alkanes, the stoichiometric coefficient of Sodium is
Answer : Option A
Explaination / Solution:
Wurtz reaction is used for the preparation of alkanes from alkyl halides in the presence of sodium and dry ether.For example: CH3Br + 2Na +BrCH3 ---------> CH3CH3 + 2NaBr
Thus two atoms of Na are used.
Q7. The number of possible conformational isomers of ethane is
zero
two
Explanation:
conformational isomers are obtained by rotation about a carbon-carbon single bond.This results in infinite number of momentary arrangements of atoms in space.Hence for ethane infinite number of conformations are possible.
Answer : Option A
Explaination / Solution:
conformational isomers are obtained by rotation about a carbon-carbon single bond.This results in infinite number of momentary arrangements of atoms in space.Hence for ethane infinite number of conformations are possible.
Q8. boiling point of alkanes
Answer : Option B
Explaination / Solution:
As molecular mass increases,the magnitude of van der Waals forces of attraction increases and hence boiling point increases accordingly.
Q9. Halogenation of alkanes is a
Answer : Option A
Explaination / Solution:
Halogenation of alkanes is a substitution reaction because the hydrogen atoms are replaced by halogens in the presence of sunlight to give the corresponding alkyl halides.The reaction follows free radical mechanism.
Q10. General formula for alkenes is
Answer : Option C
Explaination / Solution:
Alkenes are unsaturated hydrocarbons with atleast on double bond between the carbon atoms.Their general formula is CnH2n.
