In an estimation of sulphur by the carius method, 0.2175 g of the substance gave 0.5825 g of BaSO₄ . The percentage composition of S in the compound is-

1. 66%

2. 20%

3. 37%

4.82%

0.284 g of an organic substance gave 0.287 g AgCl in a carius method for the estimation of halogen. The percentage of Cl in the compound is-

1. 5%

2. 18%

3. 25%

4. 33%

0.24 g of an organic compound containing phosphorous gave 0.66 g of Mg₂P₂O₇ by the usual analysis. The percentage of phosphorous in the compound is:

1. 77%

2. 72%

3. 87%

4. 60 %

0.1688 g organic compound when analyzed by the Dumas method yields 31.7 mL of moist nitrogen measured at 14º C and 758 mm mercury pressure. The % of the nitrogen in the organic compound (Aqueous tension at 14 º C =12 mm) is:

1. 30.9%

2. 10%

3. 40%

4. 21.9 %

The latest technique for isolation, purification and separation of organic compounds is -

The method that can be used to separate two compounds with different solubilities in a solvent is-
1. Distillation
2. Isolation
3. Fractional crystallization
4. Filtration

Find the elements that can be detected by Lassaigne's test

1. Nitrogen, Sulphur, Halogens

2. Nitrogen, Cyanides, Sulphur

3. Sodium, Sulphur, Halogens, Phosphorus

4. Nitrogen, Sulphur, Halogens, Phosphorus

Halogen in an organic compound that can be detected by -

Nitric acid is added to sodium extract before adding silver nitrate for testing halogens because:

1. Nitric acid reduces sulphide

2. Nitric acid decomposes NaCN and Na₂S

3. Nitric acid oxidises the organic compound

4. Nitric acid acts as a dehydrating agent

Metallic sodium is fused with organic compounds for testing nitrogen, sulphur, and halogens. The correct reason behind this is: