Principles Related to Practical Chemistry

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)

Match List - I with List - II.

1. A-IV, B-I, C-II, D-III
2. A-III, B-IV, C-I, D-II
3. A-III, B-IV, C-II, D-I
4. A-IV, B-III, C-II, D-I

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

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)

Identify the correct statements : Choose the correct answer from the options given below :

1. D and E Only
2. A, B and E Only
3. A, B, C and E Only
4. A, B and C Only

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

Consider the following reactions. (Hot solution)PbCl2 + K2CrO4 A + 2KCl A + NaOH B + Na2CrO4 PbSO4 + 4CH3COONH4 (NH4)2SO4 + X In the above reactions, A, B and X are respectively.

1. Na2[Pb(OH)2], PbCrO4 and [Pb(NH3)4]SO4
2. Na2[Pb(OH)2], PbCrO4 and (NH4)2[Pb(CH3COO)4]
3. PbCrO4, Na2[Pb(OH)4] and (NH4)2[Pb(CH3COO)4]
4. PbCrO4, Na2[Pb(OH)4] and [Pb(NH3)4]SO4

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%

On heating a mixture of common salt and K2Cr2O7 in equal amount along with concentrated H2SO4 in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas respectively are:

1. Cr2O2Cl2 and +3
2. Cr2O2Cl2 and +6
3. CrO2Cl2 and +6
4. CrO2Cl2 and +5