JEE Main 2023 · 15 Apr 2023 Shift 1

Which of the following expressions is correct in case of a CsCl unit cell (edge length ‘a’)?

1. Ar_Cs⁺ + r_Cl⁻ = a
2. Br_Cs⁺ + r_Cl⁻ = a/√2
3. Cr_Cs⁺ + r_Cl⁻ = √3/2 a
4. Dr_Cs⁺ + r_Cl⁻ = a/2

Given below are two statements: Statement I : According to Bohr’s model of hydrogen atom, the angular momentum of an electron in a given stationary state is quantised. Statement II : The concept of electron in Bohr’s orbit, violates the Heisenberg uncertainty principle. In the light of the above statements, choose the most appropriate answer from the options given below:

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

Consider the following statements:

1. ANF₃ molecule has a trigonal planar structure.
2. BBond length of N₂ is shorter than O₂.
3. CIsoelectronic molecules or ions have identical bond order.
4. DDipole moment of H₂S is higher than that of water molecule. Choose the correct answer from the options given below:

Which of the following statement(s) is/are correct?

1. AThe pH of 1 × 10⁻⁸ M HCl solution is 8.
2. BThe conjugate base of H₂PO₄⁻ is HPO₄²⁻.
3. CKᵥ increases with increase in temperature.
4. DWhen a solution of a weak monoprotic acid is titrated against a strong base at half neutralisation point, pH = ½ pKₐ. Choose the correct answer from the options given below:

Which one of the following is not an example of calcination?

1. AFe₂O₃ · xH₂O —Δ→ Fe₂O₃ + xH₂O
2. BCaCO₃ —Δ→ CaO + CO₂
3. CCaCO₃ · MgCO₃ —Δ→ CaO + MgO + 2CO₂
4. D2PbS + 3O₂ —Δ→ 2PbO + 2SO₂

During water-gas shift reaction

1. Acarbon is oxidized to carbon monoxide.
2. Bcarbon monoxide is oxidized to carbon dioxide.
3. Ccarbon dioxide is reduced to carbon monoxide.
4. Dwater is evaporated in presence of catalyst.

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R: Assertion (A) : BeCl₂ and MgCl₂ produce characteristic flame Reason (R) : The excitation energy is high in BeCl₂ and MgCl₂ In the light of the above statements, choose the correct answer from the options given below :

1. ABoth (A) and (R) are true and (R) is the correct explanation of (A)
2. BBoth (A) and (R) are true but (R) is NOT the correct explanation of (A)
3. C(A) is true but (R) is false
4. D(A) is false but (R) is true

For a good quality cement, the ratio of silica to alumina is found to be

1. A1.5
2. B3
3. C4.5
4. D2