- 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: Qualitative Analysis of Organic Compounds |
76%
From NCERT
NEET - 2025
Please attempt this question first.
Hints
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: Qualitative Analysis of Organic Compounds |
82%
From NCERT
NEET - 2024
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
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: Qualitative Analysis of Organic Compounds |
73%
From NCERT
NEET - 2024
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
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: Qualitative Analysis of Organic Compounds |
62%
From NCERT
NEET - 2024
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Subtopic: Qualitative Analysis of Organic Compounds |
75%
From NCERT
NEET - 2024
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
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: Qualitative Analysis of Organic Compounds |
From NCERT
NEET - 2024
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
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: Qualitative Analysis of Organic Compounds |
66%
From NCERT
NEET - 2023
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
The most suitable method used for the separation of 1:1 mixture of ortho and para-nitrophenols is:
| 1. | Chromatography | 2. | Crystallization |
| 3. | Steam distillation | 4. | Sublimation |
Subtopic: Qualitative Analysis of Organic Compounds |
80%
From NCERT
NEET - 2017
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
In Kjeldahl’s method for estimation of nitrogen present in the soil sample, ammonia evolved from 0.75g of sample neutralized 10ml of 1M H2SO4. The percentage of nitrogen in the soil is:
| 1. | 37.33 | 2. | 45.85 |
| 3. | 25.75 | 4. | 43.13 |
Subtopic: Qualitative Analysis of Organic Compounds |
72%
From NCERT
AIPMT - 2014
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
Links
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
The Lassaigne’s extract is boiled with conc. while testing for halogens, because it:
1. Helps in the precipitation of
2. Increases the solubility product of
3. Increases the concentration of ions
4. Decomposes and , if formed
Subtopic: Qualitative Analysis of Organic Compounds | Quantitative Analysis of Organic Compounds |
72%
From NCERT
AIPMT - 2011
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
Links
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
- 1(current)
Q. No.
© 2025 GoodEd Technologies Pvt. Ltd.