JEE Main 2025 · 7 Apr 2025 Shift 1

At the sea level, the dry air mass percentage composition is given as nitrogen gas: 70.0, oxygen gas: 27.0 and argon gas: 3.0. If total pressure is 1.15 atm, then calculate the ratio of following respectively:

1. (i)
   partial pressure of nitrogen gas to partial pressure of oxygen gas
2. (ii)
   partial pressure of oxygen gas to partial pressure of argon gas (Given: Molar mass of N, O and Ar are 14, 16 and 40 g mol⁻¹ respectively.)

Total enthalpy change for freezing of 1 mol of water at 10°C to ice at −10°C is __________ (Given: ΔfusH = x kJ/mol Cₚ[H₂O(l)] = y J mol⁻¹ K⁻¹ Cₚ[H₂O(s)] = z J mol⁻¹ K⁻¹)

1. A−x − 10y − 10z
2. B−10(100x + y + z)
3. C10(100x + y + z)
4. Dx − 10y − 10z

An aqueous solution of HCl with pH 1.0 is diluted by adding equal volume of water (ignoring dissociation of water). The pH of HCl solution would (Given log 2 = 0.30)

1. Aremain same
2. Breduce to 0.5
3. Cincrease to 2
4. Dincrease to 1.3

Given below are two statements: Statement I: Mohr's salt is composed of only three types of ions-ferrous, ammonium and sulfate. Statement II: If the molar conductance at infinite dilution for ferrous, ammonium and sulfate ions are x₁, x₂ and x₃ S cm² mol⁻¹, respectively then the molar conductance for Mohr's salt solution at infinite dilution would be given by x₁ + x₂ + 2x₃ In the light of the given statements, choose the correct answer from the options given below:

1. ABoth Statements I and Statement II are true
2. BBoth Statements I and Statement II are false
3. CStatement I is true but Statement II are false
4. DStatement I is false but Statement II is true

The number of valence electrons present in the metal among Cr, Co, Fe and Ni which has the lowest enthalpy of atomisation is

1. A8
2. B9
3. C6
4. D10

The group 14 elements A and B have the first ionisation enthalpy values of 708 and 715 kJ mol⁻¹ respectively. The above values are lowest among their group members. The nature of their ions A²⁺ and B⁴⁺ respectively is

1. Areducing and oxidising
2. Boxidising and reducing
3. Cboth reducing
4. Dboth oxidising

The first transition series metal ‘M’ has the highest enthalpy of atomisation in its series. One of its aquated ion (Mⁿ⁺) exists in green colour. The nature of the oxide formed by the above Mⁿ⁺ ion is:

1. Abasic
2. Bacidic
3. Camphoteric
4. Dneutral

An octahedral complex having molecular composition Co.5NH₃.Cl.SO₄ has two isomers A and B. The solution of A gives a white precipitate with AgNO₃ solution and the solution of B gives white precipitate with BaCl₂ solution. The type of isomerism exhibited by the complex is,

1. ALinkage isomerism
2. BCo-ordinate isomerism
3. CIonisation isomerism
4. DGeometrical isomerism