- 1(current)
Q. No.Which one of the following reactions does not belong to "Lassaigne's test"?
| 1. | \(\mathrm{Na}+\mathrm{X} \underset{\Delta}{\longrightarrow}+\mathrm{NaX} \) |
| 2. | \(2 \mathrm{CuO}+\mathrm{C} \xrightarrow[\Delta]{} 2 \mathrm{Cu}+\mathrm{CO}_2 \) |
| 3. | \(\mathrm{Na}+\mathrm{C}+\mathrm{N} \xrightarrow[\Delta]{} \mathrm{NaCN} \) |
| 4. | \(2 \mathrm{Na}+\mathrm{S} \xrightarrow[\Delta]{} \mathrm{Na}_2 \mathrm{~S}\) |
Subtopic: Â Qualitative Analysis of Organic Compounds |
 69%
Level 2: 60%+
NEET - 2025
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Please attempt this question first.
On heating, some solid substances change from solid to vapour state without passing through liquid state. The technique used for the purification of such solid substances based on the above principle is known as:
| 1. | Sublimation | 2. | Distillation |
| 3. | Chromatography | 4. | Crystallization |
Subtopic: Â Qualitative Analysis of Organic Compounds |
 82%
Level 1: 80%+
NEET - 2024
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The method used for quantitative estimation of halogens is:
1. Dumas method
2. Carius method
3. Kjeldahl's method
4. Combustion method
1. Dumas method
2. Carius method
3. Kjeldahl's method
4. Combustion method
Subtopic: Â Qualitative Analysis of Organic Compounds |
 72%
Level 2: 60%+
NEET - 2024
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The technique used to purify liquids having high boiling points and getting decomposed at or below their boiling points is:
1. Fractional distillation
2. Steam distillation
3. Simple distillation
4. Distillation under reduced pressure
1. Fractional distillation
2. Steam distillation
3. Simple distillation
4. Distillation under reduced pressure
Subtopic: Â Qualitative Analysis of Organic Compounds |
 62%
Level 2: 60%+
NEET - 2024
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Subtopic: Â Qualitative Analysis of Organic Compounds |
 75%
Level 2: 60%+
NEET - 2024
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A steam volatile organic compound which is immiscible with water has a boiling point of \(250^\circ \text{C}\). During steam distillation, a mixture of this organic compound and water will boil:
1. Above \(100^\circ \text{C}\) but below \(250^\circ \text{C}\).
2. Above \(250^\circ \text{C}\).
3. At \(250^\circ \text{C}\).
4. Close to but below \(100^\circ \text{C}\).
1. Above \(100^\circ \text{C}\) but below \(250^\circ \text{C}\).
2. Above \(250^\circ \text{C}\).
3. At \(250^\circ \text{C}\).
4. Close to but below \(100^\circ \text{C}\).
Subtopic: Â Qualitative Analysis of Organic Compounds |
Level 3: 35%-60%
NEET - 2024
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In Lassaigne's extract of an organic compound, both nitrogen and sulphur are present, which gives blood red colour with \(\text{Fe}^{3+}\) due to the formation of:
1. \([\mathrm{Fe}(\mathrm{SCN})]^{2+} \)
2. \(\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3 \cdot \mathrm{xH}_2 \mathrm{O} \)
3. \(\mathrm{NaSCN} \)
4. \(\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NOS}\right]^{4-} \)
1. \([\mathrm{Fe}(\mathrm{SCN})]^{2+} \)
2. \(\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3 \cdot \mathrm{xH}_2 \mathrm{O} \)
3. \(\mathrm{NaSCN} \)
4. \(\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NOS}\right]^{4-} \)
Subtopic: Â Qualitative Analysis of Organic Compounds |
 66%
Level 2: 60%+
NEET - 2023
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- 1(current)
Q. No.
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