Chemistry Class-11: Chapter –12. The Organic Chemistry Some Basic Principles and Techniques Part – 5

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Question: 29

Explain, how is the electronegativity of carbon atoms related to their state of hybridisation in an organic compound?

Answer:

Electronegativity increases with increasing ‘s’ character

Question: 30

Show the polarisation of carbon-magnesium bond in the following structure.

Answer:

Since electronegativity of carbon is more than magnesium it will behave as

Question: 31

Compounds with same molecular formula but differing in their structures are said to be structural isomers. What type of structural isomerism is shown by

Answer:

Metamerism

Question: 32

Which of the following selected chains is correct to name the given compound according to IUPAC system.

Answer:

The four carbon chain. Selected chain should have maximum number of functional groups.

Question: 33

In DNA and RNA, nitrogen atom is present in the ring system. Can Kjeldahl method be used for the estimation of nitrogen present in these? Give reasons.

Answer:

DNA and RNA have nitrogen in the heterocyclic rings. Nitrogen present in rings, azo groups and nitro groups cannot be removed as ammonia.

Question: 34

If a liquid compound decomposes at its boiling point, which method (s) can you choose for its purification. It is known that the compound is stable at low pressure, steam volatile and insoluble in water.

Note : Answer the questions 35 to 38 on the basis of information given below: “Stability of carbocations depends upon the electron releasing inductive effect of groups adjacent to positively charged carbon atom involvement of neighbouring groups in Hyperconjugation and resonance.”

Question: 35

Draw the possible resonance structures for:

and predict which of the structures is more stable. Give reason for your answer.

Answer:

Structure II is more stable because every atom has complete octet

Question: 36

Which of the following ions is more stable? Use resonance to explain your answer

Answer:

Structure I is more stable due to resonance. (See resonance structure ‘A’ and ‘B’). No resonance is possible in structure II