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Principles Related to Practical Chemistry · Question 42

JEE Main 2025 (Online) 4th April Morning ShiftNumericalEasy📈 Topic in 65% papers+4
1

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)

Answer

20

Solution

Pressure of dry N2:

p1 = 900 - 15 = 885 mm Hg

Volume of N2 at STP (p0 = 760 mm Hg, T0 = 273 K):

V0 = p1 V1 T0p0 T1

= 885 150 273760 300

= 158.95 mL

∵ 22400 mL of N2 at STP weighs 28 g,

% of N = 28 V0 10022400 m

= 28 158.95 10022400 1

= 19.87\% 20\%

Answer: 20

JEE Main 2025 (Online) 4th April Morning Shift

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2

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
3

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
4

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]

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5

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
JEE Main 2025 (Online) 3rd April Evening Shift
6

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\%
JEE Main 2025 (Online) 3rd April Evening Shift
7

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
JEE Main 2025 (Online) 2nd April Morning Shift
8

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
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9

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
JEE Main 2025 (Online) 2nd April Evening Shift
10

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)
JEE Main 2025 (Online) 2nd April Evening Shift
11

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
JEE Main 2025 (Online) 29th January Morning Shift

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