HARD
11th CBSE
IMPORTANT
Earn 100

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

CH3-S-CH2-CH2-CH3 and 

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Important Questions on Organic Chemistry – Some Basic Principles and Techniques

MEDIUM
11th CBSE
IMPORTANT

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

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HARD
11th CBSE
IMPORTANT
 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.
HARD
11th CBSE
IMPORTANT
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.
HARD
11th CBSE
IMPORTANT
Note: Answer the question 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.”
Draw the possible resonance structures for CH3-O-C+H2 and predict which of the structures is more stable. Give reason for your answer.
HARD
11th CBSE
IMPORTANT

Note : Answer the question 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.”

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

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HARD
11th CBSE
IMPORTANT

Note: Answer the question 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 neighboring groups in hyperconjugation and resonance.”

 The structure of triphenylmethyl cation is given below. This is very stable and some of its salts can be stored for months. Explain the cause of high stability of this cation.

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HARD
11th CBSE
IMPORTANT

Write structures of various carbocations that can be obtained from 2-methylbutane. Arrange these carbocation’s in order of increasing stability.

HARD
11th CBSE
IMPORTANT
Three students, Manish, Ramesh and Rajni were determining the extra elements present in an organic compound given by their teacher. They prepared the Lassaigne’s extract (L.E.) independently by the fusion of the compound with sodium metal. Then they added solid FeSO4 and dilute Sulphur acid to a part of Lassaigne’s extract. Manish and Rajni obtained Prussian blue colour but Ramesh got red colour. Ramesh repeated the test with the same Lassaigne’s extract, but again got red colour only. They were surprised and went to their teacher and told him about their observation. Teacher asked them to think over the reason for this. Can you help them by giving the reason for this observation? Also, write the chemical equations to explain the formation of compounds of different colors.