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JEE Main 2025 (Online) 24th January Evening ShiftNumericalEasy📈 Topic in 24% papers+4
Ques. 1JEE Main 2025, 24 January (Evening Shift)

The observed and normal molar masses of compound MX2 are 65.6 and 164 respectively. The percent degree of ionisation of MX2 is %. (Nearest integer)

Answer

75

Solution

MX2 M2++2X- n=3; i= 16465.6=2.5

i=1+(n-1) 1+2 =2.5 =0.75

Answer: 75

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Ques. 2JEE Main 2025, 23 January (Morning Shift)

CrCl3 xNH3 can exist as a complex. 0.1 molal aqueous solution of this complex shows a depression in freezing point of 0.558 C. Assuming 100% ionisation of this complex and coordination number of Cr is 6, the complex will be (Given Kf = 1.86 K kg mol-1)

  1. [Cr(NH3)5Cl]Cl2
  2. [Cr(NH3)4Cl2]Cl
  3. [Cr(NH3)6]Cl3
  4. [Cr(NH3)3Cl3]
Ques. 3JEE Main 2025, 23 January (Evening Shift)

When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if decrease in vapour pressure is 20 mm of Hg ?

  1. 0.2
  2. 0.4
  3. 0.8
  4. 0.6
Ques. 4JEE Main 2025, 23 January (Evening Shift)

Consider a binary solution of two volatile liquid components 1 and 2. x1 and y1 are the mole fractions of component 1 in liquid and vapour phase, respectively. The slope and intercept of the linear plot of 1x1 vs 1y1 are given respectively as :

  1. P10P20, P10-P20P20
  2. P20P10, P20-P10P10
  3. P20P10, P10-P20P20
  4. P10P20, P20-P10P20
Ques. 5JEE Main 2025, 22 January (Morning Shift)

Arrange the following solutions in order of their increasing boiling points. (i) 10-4 M NaCl (ii) 10-4 M Urea (iii) 10-3 M NaCl (iv) 10-2 M NaCl

  1. (i) < (ii) < (iii) < (iv)
  2. (ii) < (i) < (iii) < (iv)
  3. (iv) < (iii) < (i) < (ii)
  4. (ii) < (i) (iii) < (iv)
Ques. 6JEE Main 2025, 22 January (Evening Shift)

Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is :

  1. 2.79 m
  2. 2 m
  3. 1.79 m
  4. 3 m
Ques. 7JEE Main 2024, 9 April (Morning Shift)

0.05 M CuSO4 when treated with 0.01 M K2Cr2O7 gives green colour solution of Cu2Cr2O7. The two solutions are separated as shown below : [SPM : Semi Permeable Membrane] [figure] Due to osmosis :

  1. Molarity of K2Cr2O7 solution is lowered.
  2. Green colour formation observed on side Y.
  3. Molarity of CuSO4 solution is lowered.
  4. Green colour formation observed on side X.
Ques. 8JEE Main 2024, 9 April (Morning Shift)

Molarity (M) of an aqueous solution containing x g of anhyd. CuSO4 in 500 mL solution at 32 is 2 10-1 M. Its molality will be 10-3 m. (nearest integer). [Given density of the solution = 1.25 g/mL]

Ques. 9JEE Main 2024, 9 April (Evening Shift)

The vapor pressure of pure benzene and methyl benzene at 27 C is given as 80 Torr and 24 Torr, respectively. The mole fraction of methyl benzene in vapor phase, in equilibrium with an equimolar mixture of those two liquids (ideal solution) at the same temperature is 10-2 (nearest integer)

Ques. 10JEE Main 2024, 8 April (Morning Shift)

A solution containing 10 g of an electrolyte AB2 in 100 g of water boils at 100.52°C. The degree of ionization of the electrolyte ( ) is 10-1. (nearest integer) [Given : Molar mass of AB2 = 200 g mol-1, Kb (molal boiling point elevation const. of water) = 0.52 K kg mol-1, boiling point of water = 100°C; AB2 ionises as AB2 A2+ + 2B-]

Ques. 11JEE Main 2024, 8 April (Evening Shift)

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is (Integer answer) (Given : Molar mass in g mol-1 Ethyl alcohol : 46 water : 18)

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