Principles Related to Practical Chemistry

Complete combustion of X g of an organic compound gave 0.25 g of CO2 and 0.12 g of H2O. If the % of carbon is 25% and of hydrogen is 4.89%, then X = 10-3 g. (Nearest integer) (Molar mass of C, H and O are 12, 1 and 16 g mol-1 respectively.)

1. 273
2. 27
3. 2730
4. 227

A student has been given 0.314 g of an organic compound and asked to estimate sulphur. During the experiment, the student has obtained 0.4813 g of barium sulphate. The percentage of sulphur present in the compound is . (Given molar mass in g mol-1 S : 32, BaSO4 : 233)

1. 63.15%
2. 21.05%
3. 48.24%
4. 42.10%

In Carius method 0.2425 g of an organic compound gave 0.5253 g silver chloride. The percentage of chlorine in the organic compound is

1. 87.65%
2. 53.58%
3. 37.57%
4. 34.79%

When 1 g of compound (X) is subjected to Kjeldahl's method for estimation of nitrogen, 15 mL 1 M H2SO4 was neutralized by ammonia evolved. The percentage of nitrogen in compound (X) is :

1. 0.21
2. 21
3. 42
4. 0.42

In Carius method, 0.75 g of an organic compound gave 1.2 g of barium sulphate, find percentage of sulphur (molar mass 32 g mol-1). Molar mass of barium sulphate is 233 g mol-1.

1. 4.55%
2. 16.48%
3. 10.30%
4. 21.97%

By usual analysis, 1.00 g of compound (X) gave 1.79 g of magnesium pyrophosphate. The percentage of phosphorus in compound (X) is : (nearest integer) (Given, molar mass in g mol-1: O = 16, Mg = 24, P = 31)

1. 40
2. 30
3. 20
4. 50

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g H2O and 0.307 g CO2. The percentages of hydrogen and oxygen in the given organic compound respectively are:

1. 7.55, 43.85
2. 6.72, 53.41
3. 6.72, 39.87
4. 53.41, 39.6

In Dumas' method for estimation of nitrogen 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound is (Given : Aqueous tension at 300 K = 15 mm Hg)

1. 15.71\%
2. 17.46\%
3. 7.85\%
4. 20.95\%

In Dumas' method for estimation of nitrogen, 0.5 gram of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound (Aqueous tension at 300 K = 15 mm Hg) is %.

1. 20.87
2. 12.57
3. 1.257
4. 18.67

Given below are two statements I and II. In the light of the above statements, choose the correct answer from the options given below

1. Statement I is true but Statement II is false
2. Statement I is false but Statement II is true
3. Both Statement I and Statement II are true
4. Both Statement I and Statement II are false

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

In Kjeldahl's method for estimation of nitrogen, CuSO4 acts as :

1. catalytic agent
2. hydrolysis agent
3. reducing agent
4. oxidising agent