Principles Related to Practical Chemistry

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

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

Match the LIST-I with LIST-II Choose the correct answer from the options given below:

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

When a salt is treated with sodium hydroxide solution it gives gas X. On passing gas X through reagent Y a brown coloured precipitate is formed. X and Y respectively, are

1. X = NH3 and Y = HgO
2. X = NH4Cl and Y = KOH
3. X = NH3 and Y = K2HgI4 + KOH
4. X = HCl and Y = NH4Cl

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)

A mixture of 1 g each of chlorobenzene, aniline, and benzoic acid is dissolved in 50 mL ethyl acetate and placed in a separating funnel. 5 M NaOH (30 mL) was added in the same funnel. The funnel was shaken vigorously and then kept aside. The ethyl acetate layer in the funnel contains :

1. chlorobenzene and aniline
2. benzoic acid and aniline
3. benzoic acid
4. benzoic acid and chlorobenzene

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)

Match List-I with List-II Choose the correct answer from the options given below :

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

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]

Compounds that should not be used as primary standards in titrimetric analysis are : Choose the most appropriate answer from the options given below:

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

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\%

Choose the correct tests with respective observations. Choose the correct answer from the options given below :

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

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

Formation of Na4[Fe(CN)5NOS], a purple coloured complex formed by addition of sodium nitroprusside in sodium carbonate extract of salt indicates the presence of:

1. Sulphide ion
2. Sulphite ion
3. Sulphate ion
4. Sodium ion

Match List-I with List-II. Choose the correct answer from the options given below:

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

The steam volatile compounds among the following are : Choose the correct answer from the options given below :

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

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

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

The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is

1. Cr3+
2. Ti3+
3. Ni2+
4. Mn2+

The purification method based on the following physical transformation is : (X)Solid Heat (X)Vapour Cool (X)Solid

1. Extraction
2. Crystallization
3. Distillation
4. Sublimation

Identify the inorganic sulphides that are yellow in colour : Choose the correct answer from the options given below :

1. (D) and (E) only
2. (A) and (B) only
3. (A), (D) and (E) only
4. (A) and (C) only