The purification method based on the difference in solubilities of the compound and the impurities in a solvent is -
1. Crystallisation
2. Distillation
3. Chromatography
4. Isolation
1. Crystallisation
2. Distillation
3. Chromatography
4. Isolation
The 3° carbon atom in the given structure is :
\(\mathrm{H}_3 \mathrm{C}-\mathrm{CH}_2-\mathrm{CH}\left(\mathrm{CH}_3\right)-\mathrm{CH}_2-\mathrm{CH}_3\\ ~~a~~~~~~~~~~~b~~~~~~~~~~~~~c~~~~~~~~~~~~~~~~~~~d~~~~~~~~~~~e\)
1. a
2. b
3. c
4. e
In which of the following compounds, the carbon marked with an asterisk is most electronegative?
1.
2.
3.
4.
The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapor in the vapor phase. A suitable method for the extraction of these oils from the flowers is
| 1. | Distillation | 2. | Crystallisation |
| 3. | Distillation under pressure | 4. | Steam distillation |
The correct order of decreasing stability of the following carbocations is:
| I | \( \begin{aligned} &~~~~~~~~~~~~\oplus\\ & CH_3 - CH-CH_3 \end{aligned}\) |
| II | \( \begin{aligned} &~~~~~~~~~~~~\oplus\\ & CH_3 - CH-OCH_3\end{aligned}\) |
| III | \( \begin{aligned} & ~~~~~~~~~~~~\oplus\\ &CH_3 - CH-CH_2- OCH_3\end{aligned}\) |
| 1. | II > I > III | 2. | I > II > III |
| 3. | II < I < III | 4. | I < II < III |
Match the terms mentioned in Column-I with the terms in Column-II.
| Column-I (Term) | Column-II (Definition) | ||
| A. | Carbocation | (i) | Species that can receive a pair of electrons. |
| B. | Nucleophile | (ii) | Conjunction of electrons of \(C-H ~\sigma-\) bond with the empty p-orbital present in adjacent positively charged carbon. |
| C. | Hyperconjugation | (iii) | sp2 hybridised carbon with empty p-orbital. |
| D. | Electrophile | (iv) | Species that can donate a pair of electrons. |
| Options: | A | B | C | D |
| 1. | (iii) | (iv) | (ii) | (i) |
| 2. | (i) | (ii) | (iii) | (iv) |
| 3. | (i) | (iv) | (iii) | (ii) |
| 4. | (iv) | (i) | (iii) | (ii) |
Match Column I with Column II.
| Column I | Column II | ||
| A. | Dumas method | 1. | AgNO3 |
| B. | Kjeldahl’s method | 2. | Silica gel |
| C. | Carius method | 3. | Nitrogen gel |
| D. | Chromatography | 4. | Ammonium sulphate |
Choose the correct answer from the options given below:
| A | B | C | D | |
| 1. | 3 | 4 | 1 | 2 |
| 2. | 1 | 2 | 3 | 4 |
| 3. | 1 | 4 | 3 | 2 |
| 4. | 4 | 1 | 3 | 2 |
| Assertion (A): | Simple distillation can help in separating a mixture of propan-1-ol (boiling point 97°C ) and propanone (boiling point 56°C ). |
| Reason (R): | Liquids with a difference of more than 20°C in their boiling points can be separated by simple distillation. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
| 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. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
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