Chemistry Class-11: Chapter –12. The Organic Chemistry Some Basic Principles and Techniques Part – 8
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Question: 48
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.
Answer:
Simple distillation can be used because the two compounds have a difference of more than in their boiling points and both the liquids can be distilled without any decomposition.
Question: 49
Which of the two structures (A) and (B) given below is more stabilized by resonance? Explain.
Answer:
Resonating structures are as follows:
(A)
Mechanism
(B)
Mechanism
Mechanism
Structure ‘B’ is more stabilized as it does not involve charge separation.
IV. Matching Type
In the following questions more than one correlation is possible between options of Column I and Column II. Make as many correlations as you can.
Question: 50
Match the type of mixture of compounds in Column I with the technique of separation/purification given in Column II.
Column I | Column I | ||
(i) | Two solids which have different solubility’s 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 |
Answer:
(i) → (e) (ii) → (d) (iii) → (a) (iv) → (b) (v) → (c)
Question: 51
Match the terms mentioned in Column I with the terms in Column II
Column I | Column I | ||
(i) | Carbocation | a | Cyclohexane and 1- hexane |
(ii) | Nucleophile | b | Conjugation of electrons of bond with empty p-orbital present at adjacent positively charged carbon. |
(iii) | Hyperconjugation | c | hybridised carbon with empty p-orbital |
(iv) | Isomers | d | Ethyne |
(v) | hybridisation | e | Species that can receive a pair of electrons |
(vi) | Electrophile | Species that can supply a pair of electrons | |
Answer:
(i) → (c) (ii) → (f ) (iii) → (b) (iv) → (a) (v) → (d) (vi) → (e)
Question: 52
Match Column I with Column II.
Column I | Column I | ||
(i) | Dumas method | a | |
(ii) | Kjeldahl method | b | Silica gel |
(iii) | Carious method | c | Nitrogen gas |
(iv) | Chromatography | d | Free radicals |
(v) | Hemolysis | e | Ammonium sulphate |
Answer:
(i) → (c) (ii) → (e) (iii) → (a) (iv) → (b) (v) → (d)
Question: 53
Match the intermediates given in Column I with their probable structure in Column II.
Column I | Column I | ||
(i) | Free radical | a | Trigonal planar |
(ii) | Carbocation | b | Pyramidal |
(iii) | Carbanion | c | Linear |
Answer:
(i) → (a), (ii) → (a) (iii) → (b)
Question: 54
Column I | Column I | ||
(i) |  Compound to Match | a | |
(ii) | b | Stable due to resonance | |
(iii) | c | Destabilized due to inductive effect | |
(iv) | Stabilized by hyperconjugation | d | A secondary carbocation |
Answer:
(i) → (a), (b), (d) (ii) → (b) (iii) → (b) (iv) → (c), (d)