JEE Main 2025 · 3 Apr 2025 Shift 1

Among 10⁻⁹ g (each) of the following elements, which one will have the highest number of atoms? Element: Pb, Po, Pr and Pt

1. APb
2. BPo
3. CPr
4. DPt

Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?

1. AAn atom can take only certain distinct energies E₁, E₂, E₃, etc. These allowed states of constant energy are called the stationary states of atom.
2. BAn atom in a stationary state does not emit electromagnetic radiation as long as it stays in the same state.
3. CWhen an electron makes a transition from a higher energy stationary state to a lower energy stationary state, then it emits a photon of light.
4. DThe electron in a H atom's stationary state moves in a circle around the nucleus.

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is: (Given : Ebullioscopic constant of water = 0.52 K kg mol⁻¹)

1. A379.2 K
2. B277.3 K
3. C377.3 K
4. D375.3 K

In the following system, PCl₅(g) ⇌ PCl₃(g) + Cl₂(g) at equilibrium, upon addition of xenon gas at constant T & p, the concentration of

1. APCl₃ will increase
2. BCl₂ will decrease
3. CPCl₅ will increase
4. DPCl₅, PCl₃ & Cl₂ remain constant

Correct order of limiting molar conductivity for cations in water at 298 K is :

1. AMg²⁺ > H⁺ > Ca²⁺ > K⁺ > Na⁺
2. BH⁺ > Na⁺ > K⁺ > Ca²⁺ > Mg²⁺
3. CH⁺ > Na⁺ > Ca²⁺ > Mg²⁺ > K⁺
4. DH⁺ > Ca²⁺ > Mg²⁺ > K⁺ > Na⁺

Given below are two statements: Statement I : A catalyst cannot alter the equilibrium constant (Kc) of the reaction, temperature remaining constant. Statement II : A homogenous catalyst can change the equilibrium composition of a system, temperature remaining constant. In the light of the above statements, choose the correct answer from the options given below

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

In a reaction A + B → C, initial concentrations of A and B are related as [A]₀ = 8[B]₀. The half lives of A and B are 10 min and 40 min, respectively. If they start to disappear at the same time, both following first order kinetics, after how much time will the concentration of both the reactants be same?

1. A20 min
2. B40 min
3. C60 min
4. D80 min

Which of the following statements are correct?

1. AThe process of adding an electron to a neutral gaseous atom is always exothermic.
2. BThe process of removing an electron from an isolated gaseous atom is always endothermic.
3. CThe 1st ionization energy of boron is less than that of beryllium.
4. DThe electronegativity of C is 2.5 in CH₄ and CCl₄
5. ELi is the most electropositive among elements of group I. Choose the correct answer from the options given below: