52
Subjective
Match column I with column II.
| Column I | Column II | ||
|---|---|---|---|
| A. | Dumas method | 1. | AgNO$$_3$$ |
| B. | Kjeldahl's method | 2. | Silica gel |
| C. | Carius method | 3. | Nitrogen gel |
| D. | Chromatography | 4. | Free radicals |
| E. | Homolysis | 5. | Ammonium sulphate |
Explanation
A - 3, B - 5, C - 1, D - 2, E - 4
| Column I | Column II | Explanation | |
|---|---|---|---|
| A. | Dumas method | Nitrogen gel | Used for N containing compounds |
| B. | Kjeldahl's method | Ammonium sulphate | Nitrogen converts to ammonium sulphate |
| C. | Carius method | AgNO$$_3$$ | Compound is heated in presence of AgNO$$_3$$ |
| D. | Chromatography | Silica gel | Adsorbent used is silica gel |
| E. | Homolysis | Free radical | Free radicals are formed by homolytic fission |
53
Subjective
Match the intermediates given in Column I with their probable structure in Column II.
| Column I | Column II | ||
|---|---|---|---|
| A. | Free radical | 1. | Trigonal planar |
| B. | Carbocation | 2. | Pyramidal |
| C. | Carbanion | 3. | Linear |
Explanation
A - 1, B - 1, C - 2
| Column I | Column II | Explanation | |
|---|---|---|---|
| A. | Free radical | Trigonal planar | Free radicals are formed by homolytic fission e.g... ${ }^{\Upsilon} \mathrm{H}_3$ hybridisation $s p^2$ |
| B. | Carbocation | Trigonal planar | Formed by heterolytic fission when carbon is attached to a more electronegative atom |
| C. | Carcanion | Pyramidal | Formed by heterolytic fission when carbon is attached to more electropositive atom e.g.. $\mathrm{CH}_3^{-}$hybridisation $\mathrm{sp}^3$ |
54
Subjective
Match the ions given in Column I with their nature given in Column II.
| Column I | Column II | ||
|---|---|---|---|
| A. |  |
1. | Stable due to resonance |
| B. | $\mathrm{F}_3-\mathrm{C}^{\oplus}$ | 2. | Destablised due to inductive effect |
| C. |  |
3. | Stabilised by hyperconjugation |
| D. | $\mathrm{CH}_3-\stackrel{\oplus}{\mathrm{C}} \mathrm{H}-\mathrm{CH}_3$ | 4. | A secondary carbocation |
Explanation
A - (1, 2), B - (2), C - (2), D - (3, 4)
| Column I | Column II | Explanation | |
|---|---|---|---|
| A. |  |
Stable due to resonance Destabilised due to inductive effect |
|
| B. | $\mathrm{F}_3-\mathrm{C}^{+}$ | Destabilised due to inductive effect | $$-I$$ effect of F creates electron deficiency at carbon $\mathrm{C}^{+}$ |
| C. |  |
Destablised due to inductive effect | + l effect of $\mathrm{CH}_3$ increases electron density at carbon $\mathrm{C}^{-}$ |
| D. | $\mathrm{CH}_3-\stackrel{\oplus}{\mathrm{C}} \mathrm{H}-\mathrm{CH}_3$ | A secondary carbocation stabilised due to hyperconjugation | $\stackrel{+}{\mathrm{C}} \mathrm{H}$ is attached to two carbon. It can also be stabilised by hyperconjugation. |
55
MCQ (Single Correct Answer)
Assertion (A) Simple distillation can help in separating a mixture of propan-1-ol (boiling point $97^{\circ} \mathrm{C}$ ) and propanone (boiling point $56^{\circ} \mathrm{C}$ ).
Reason (R) Liquids with a difference of more than 201 CC in their boiling points can be separated by simple distillation.
A
Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$
B
Both $A$ and $R$ are correct but $R$ is not the correct explanation of $A$
C
Both $A$ and $R$ are not correct
D
A is not correct but $R$ is correct
56
MCQ (Single Correct Answer)
Assertion (A) Energy of resonance hybrid is equal to the average of energies of all canonical forms.
Reason (R) Resonance hybrid cannot be presented by a single structure.
A
Both A and R are correct and R is the correct explanation of A
B
Both $A$ and $R$ are correct but $R$ is not the correct explanation of $A$
C
Both A and R are not correct
D
A is not correct but R is correct