Principles Related to Practical Chemistry

In an estimation of sulphur by Carius method 0.2 g of the substance gave 0.6 g of BaSO4. The percentage of sulphur in the substance is %. (Given molar mass in g mol-1 S : 32, BaSO4 : 233)

2.0 g of a bromo hydrocarbon (X) was subjected to Carius analysis, gave 3.36 g of AgBr. The percentage of carbon in the compound (X) is 26.7%. Total number of carbon atoms in the empirical formula for compound (X) is . (Given molar mass in g mol-1 H : 1, C : 12, Br : 80, Ag : 108)

In sulphur estimation, 2.0 10-3 mol of an organic compound (X) (molar mass 76 g mol-1) gave 0.4813 g of barium sulphate (molar mass 233 g mol-1). The percentage of sulphur in the compound (X) is 10-1 % (Nearest integer)

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

0.53 g of an organic compound (x) when heated with excess of nitric acid (concentrated) and then with silver nitrate gave 0.75 g of silver bromide precipitate. 1.0 g of (x) gave 1.32 g of CO2 gas on combustion. The percentage of hydrogen in the compound (x) is %. [Nearest Integer] [Given: Molar mass in g mol-1 H : 1, C : 12, Br : 80, Ag : 108, O : 16; Compound (x) : CxHyBrz]

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 Dumas method for estimation of nitrogen, 0.50 g of an organic compound gave 70 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the organic compound is %. (Aqueous tension at 300 K is 15 mm).

0.25 g of an organic compound "A" containing carbon, hydrogen and oxygen was analysed using the combustion method. There was an increase in mass of CaCl2 tube and potash tube at the end of the experiment. The amount was found to be 0.15 g and 0.1837 g, respectively. The percentage of oxygen in compound A is %. (Nearest integer) (Given: molar mass in g mol-1 H : 1, C : 12, O : 16)

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%

Sodium fusion extract of an organic compound (Y) with CHCl3 and chlorine water gives violet color to the CHCl3 layer. 0.15 g of (Y) gave 0.12 g of the silver halide precipitate in Carius method. Percentage of halogen in the compound (Y) is . (Nearest integer) (Given : molar mass g mol-1 C : 12, H : 1, Cl : 35.5, Br : 80, I : 127)

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

An organic compound weighing 500 mg, produced 220 mg of CO2, on complete combustion. The percentage composition of carbon in the compound is %. (nearest integer) (Given molar mass in g mol-1 of C : 12, O : 16)

In Dumas' method 292 mg of an organic compound released 50 mL of nitrogen gas (N2) at 300 K temperature and 715 mm Hg pressure. The percentage composition of 'N' in the organic compound is % (Nearest integer) (Aqueous tension at 300 K = 15 mm Hg)

In Dumas' method for estimation of nitrogen 1 g of an organic compound gave 150 mL of nitrogen collected at 300 K temperature and 900 mm Hg pressure. The percentage composition of nitrogen in the compound is % (nearest integer) (Aqueous tension at 300 K = 15 mm Hg)

During estimation of nitrogen by Dumas' method of compound X (0.42 g) [figure] mL of N2 gas will be liberated at STP. (nearest integer) (Given molar mass in g mol-1 : C : 12, H : 1, N : 14)

0.5 g of an organic compound on combustion gave 1.46 g of CO2 and 0.9 g of H2O. The percentage of carbon in the compound is . (Nearest integer) [Given : Molar mass (in g mol-1) C : 12, H : 1, O : 16]

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