HARD
11th CBSE
IMPORTANT
Earn 100

Which of the following compounds will not exist as resonance hybrid. Give reason for your answer:
(i) (ii) (iii)

Important Questions on Organic Chemistry – Some Basic Principles and Techniques
HARD
11th CBSE
IMPORTANT
Which of the following compound will not exist as resonance hybrid. Give reason for your answer:

MEDIUM
11th CBSE
IMPORTANT
Why does act as an electrophile?

HARD
11th CBSE
IMPORTANT
Resonance structures of propenal are given below. Which of these resonating structure is more stable? Give reason for your answer.

HARD
11th CBSE
IMPORTANT
By mistake, an alcohol (boiling point ) was mixed with a hydrocarbon (boiling point ). Suggest a suitable method to separate the two compounds. Explain the reason for your choice.

HARD
11th CBSE
IMPORTANT
Which of the two structures and given below is more stabilised by resonance? Explain.
and

MEDIUM
11th CBSE
IMPORTANT
Match the type of mixture of compounds in Column I with the technique of separation/purification given in Column II.
Column I | Column II |
(i) Two solids which have different solubilities in a solvent and which do not undergo reaction when dissolved in it. | (a) Steam distillation |
(ii) Liquid that decomposes at its boiling point |
(b) Fractional distillation |
(iii) Steam volatile liquid |
(c) Simple distillation |
(iv) Two liquids which have boiling points close to each other |
(d) Distillation under reduced pressure |
(v) Two liquids with large difference in boiling points. | (e) Crystallization |

HARD
11th CBSE
IMPORTANT
Match the terms mentioned in Column I with the terms in Column II.
Column I | Column II | ||
(i) | Carbocation | (a) | Cyclohexane and -hexene |
(ii) | Nucleophile | (b) | Conjugation of electrons of bond with empty -orbital present at adjacent positively charged carbon. |
(iii) | Hyperconjugation | (c) | hybridised carbon with the empty orbital |
(iv) | Isomers | (d) | Ethyne |
(v) | hybridisation | (e) | Species that can revive a pair of electrons |
(vi) | Electrophile | (f) | Species that can supply a pair of electrons |

MEDIUM
11th CBSE
IMPORTANT
Match Column I with Column II.
Column I | Column II | ||
(i) | Dumas method | (a) | |
(ii) | Kjeldahl's method | (b) | Silica gel |
(iii) | Carius method | (c) | Nitrogen gas |
(iv) | Chromatography | (d) | Free radicals |
(v) | Homolysis | (e) | Ammonium sulphate |
