Hydrocarbons - Online Test

Q1. The non-aromatic compound among the following is

Answer : Option B
Explaination / Solution:

The compound B does not satisfy the (4n+2)pi electron rule and is therefore not an aromatic compound.

Q2. A dibromo derivative of an alkane reacts with sodium metal to form an alicyclic hydrocarbon. The derivative is ______.
Answer : Option D
Explaination / Solution:

1,4 - dibromobutane ( ie. a  dibromoderivative of an alkane , butane)   when reacted withl  in ethereal solution produces alicyclic hydrocarbon, Cyclobutane  as per following reaction.

Therefore , the dibromo-derivative of alkane is identified   as 1 , 4-dibromobutane.


Q3. Which one of these is NOT TRUE for benzene? Explanation: Benzene forms mono substituted product.
Answer : Option C
Explaination / Solution:
No Explaination.


Q4. One mole of a symmetrical alkene on ozonolysis, and subsequent treatment with ( Zn / H2 O ) gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is ---------.?
Answer : Option D
Explaination / Solution:

Ozonolysis of alkenes involves the addition of ozone molecule to alkene to form an unstable ozonide , and then cleavage of the ozonide by  to smaller molecules .  

2- butene is a symmetrical alkene , which on ozonolysis yields two moles of   having molecular mass   of 44 u. as per reaction given   below,

 

 


Q5. n-propyl bromide on treating with alcoholic KOH produces
Answer : Option C
Explaination / Solution:

Elimination reaction takes place.

Q6.

In the following sequence of reactions, the alkene is converted to  compound   


The compound  is --------- ?

Answer : Option A
Explaination / Solution:

The given sequence of conversion  steps  represent Ozonolysis of 2-Butene , which follows the following path ,

1 .   Formation of an unstable intermediate / ozonide

2 . Cleavage   of the  intermediate / ozonide  by  to smaller molecules , giving out the compound   , which is  CH3 CHO  (  Ethanal )  

 

The reaction is well depicted as below ,  

,


Q7. The reagent(s) for the following conversion, is/are

Answer : Option C
Explaination / Solution:

Alcoholic KOH followed by  is used. Both are bases. is better base than alc.KOH.

Q8. Presence of a nitro group in a benzene ring
Answer : Option B
Explaination / Solution:

This is because the Nitro is electron withdrawing group,it pulls the electron density from the ring towards itself thereby decreasing the electron density in the ring and deactivating the ring towards attack by the electrophile.

Q9.
The compound formed as a result of oxidation of ethyl benzene by  is

Answer : Option C
Explaination / Solution:

Alkyl benzene on oxidation with  give benzoic acid.

Q10. The general formula of a cycloalkane is
Answer : Option B
Explaination / Solution:

Cycloalkanes have general formula of