The colour of the solution that gets formed by mixing sodium nitroprusside to an alkaline solution of sulfide ions, is-

In Kjeldahl's method, the nitrogen present is estimated as-

1. N₂ 

2. NH₃

3. NO₂ 

4 None of the above

In Duma’s method for estimation of nitrogen, 0.25g of an organic compound gave 40 mL

of nitrogen collected at 300 K temperature and 725 mm pressure. If the aqueous tension

at 300 K is 25 mm, the percentage of nitrogen in the compound is

1. 17.36

2. 18.20..

3. 16.76

4. 15.76

In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralised 10 mL of 1 M H₂SO₄. The percentage of nitrogen in the soil is

1. 37.33             2. 45.33

3. 35.33             4. 43.33

The Lassaigne's extract is boiled with a concentration HNO₃ while testing for halogens. By doing so it:

1. Helps in the precipitation of AgCl.

2. Increases the solubility product of AgCl.

3. Increases the concentration of NO₃^- ions.

4. Decomposes Na₂S and NaCN, if formed.

Ether and benzene can be separated by :-

(1) Filtration

(2) Distillation

(3) Crystallization

(4) Sublimation

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 nitrogen in the organic compound (Aqueous tension at 14 º C =12 mm) is-

1. 30.9%

2. 10%

3. 40%

4. 21.9 %

0.6 g of an organic compound was Kjeldahlised and NH₃ evolved was absorbed into 50 mL of semi-normal solution of H₂SO₄. The residual acid solution was diluted with distilled water and the volume made up to 150 mL. 20 mL of this diluted solution required 35 mL of N/20 NaOH solution for complete neutralization.

1. 24.2% 

2. 32.4%

3.27.6 %

4. 20.8%

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

0.3780 grams of an organic chloro compound gave 0.5740 grams of silver chloride in Carius estimation. % of chlorine present in the compound is -