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)

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]

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)

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)

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 the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is 10-1\%. (Molar mass : O = 16, S = 32, Ba = 137 in g mol-1)

Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with K4[Fe(CN)6] is . Cu2+, Fe3+, Ba2+, Ca2+, NH4+, Mg2+, Zn2+

In Carius method of estimation of halogen, 0.25 g of an organic compound gave 0.15 g of silver bromide (AgBr). The percentage of Bromine in the organic compound is 10-1\% (Nearest integer). (Given : Molar mass of Ag is 108 and Br is 80 g mol-1)

During " S " estimation, 160 mg of an organic compound gives 466 mg of barium sulphate. The percentage of Sulphur in the given compound is %. (Given molar mass in g mol-1 of Ba : 137, S : 32, O : 16)

In Carius method for estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl. The percentage composition of chlorine in the compound is %. (Given : molar mass in g mol-1 of Ag:108, Cl:35.5)

[figure] In the given TLC, the distance of spot A & B are 5 cm & 7 cm, from the bottom of TLC plate, respectively. Rf value of B is x 10-1 times more than A. The value of x is .

Consider the following test for a group-IV cation. M2+ + H2S A (Black precipitate) + byproduct A + aqua regia B + NOCl + S + H2O B + KNO2 + CH3COOH C + byproduct The spin-only magnetic moment value of the metal complex C is BM (Nearest integer)

Consider the following reactions NiS + HNO3 + HCl A + NO + S + H2O [figure] The number of protons that do not involve in hydrogen bonding in the product B is .

[figure] In a borax bead test under hot condition, a metal salt (one from the given) is heated at point B of the flame, resulted in green colour salt bead. The spin-only magnetic moment value of the salt is BM (Nearest integer) [Given atomic number of Cu = 29, Ni = 28, Mn = 25, Fe = 26]

Using the given figure, the ratio of Rf values of sample A and sample C is x 10-2. Value of x is . [figure]

The number of white coloured salts, among the following is (a) SrSO4 (b) Mg(NH4)PO4 (c) BaCrO4 (d) Mn(OH)2 (e) PbSO4 (f) PbCrO4 (g) AgBr (h) PbI2 (i) CaC2O4 (j) [Fe(OH)2(CH3COO)]

Following Kjeldahl's method, 1 g of organic compound released ammonia, that neutralised 10 mL of 2 M H2SO4. The percentage of nitrogen in the compound is %.

Molar mass of the salt from NaBr, NaNO3, KI and CaF2 which does not evolve coloured vapours on heating with concentrated H2SO4 is g mol-1. (Molar mass in g mol-1 : Na : 23, N : 14, K : 39, O : 16, Br : 80, I : 127, F : 19, Ca : 40)

On a thin layer chromatographic plate, an organic compound moved by 3.5 cm, while the solvent moved by 5 cm. The retardation factor of the organic compound is 10-1.

Number of metal ions characterized by flame test among the following is . Sr2+, Ba2+, Ca2+, Cu2+, Zn2+, Co2+, Fe2+

The oxidation number of iron in the compound formed during brown ring test for NO3- ion is .