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Principles Related to Practical Chemistry · Question 36

JEE Main 2025 (Online) 8th April Evening ShiftMCQEasy📈 Topic in 65% papers+4−1
1

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

Answer

(2) 6.72, 53.41

Solution

Percentage of hydrogen:

\%H = 218 0.1270.210 100

= 6.72

Percentage of carbon:

\%C = 1244 0.3070.210 100

= 39.87

Percentage of oxygen (by difference):

\%O = 100 - (6.72 + 39.87)

= 53.41

H = 6.72 % and O = 53.41 %

Answer: (2)

JEE Main 2025 (Online) 8th April Evening Shift

Keep practising — Principles Related to Practical Chemistry

2

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
JEE Main 2025 (Online) 8th April Evening Shift
3

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
JEE Main 2025 (Online) 7th April Morning Shift
4

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)

JEE Main 2025 (Online) 7th April Morning Shift
5

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
JEE Main 2025 (Online) 7th April Evening Shift
6

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)

JEE Main 2025 (Online) 7th April Evening Shift
7

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)

JEE Main 2025 (Online) 4th April Morning Shift
8

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)
JEE Main 2025 (Online) 4th April Evening Shift
9

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)

JEE Main 2025 (Online) 3rd April Morning Shift
10

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]

JEE Main 2025 (Online) 3rd April Morning Shift
11

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
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