Practice paper · Annual

Which of the following contains the maximum number of atoms? (Molar mass of He = 4 g, Na = 23 g, Ca = 40 g)

1. A4 g He
2. B46 g Na
3. C0.40 moles of Ca
4. D12 g He

5 moles of AB₂ weighs 125 g and 10 moles of A₂B₂ weighs 300 g. The molar mass of A and B (in g mol⁻¹ ) respectively are:

1. A10, 5
2. B50, 25
3. C25, 50
4. D5, 10

The electrons, identified by quantum numbers n and l are- (I) n = 4, l = 1, (II) n = 4, l = 0, (III) n = 3, l = 2, (IV) n = 3, l = l the correct order of increasing energy, from the lowest to highest is-

1. A(IV) < (II) < (III) < (I)
2. B(II) < (IV) < (I) < (III)
3. C(I) < (III) < (II) < (IV)
4. D(III) < (I) < (IV) < (II)

Consider the following molecules: (I) CO₂ (II) H₂O (III) BF₃ (IV) NH₃ Out of these, molecule(s) having sp³ hybridization of central atom is/are-

1. AI, II, III, IV
2. BI, II
3. CII, IV
4. DIV only

Which of the following molecule is paramagnetic having bond order two?

1. AC₂
2. BN₂
3. CO₂
4. DF₂

For an isolated system,

1. A∆U = 0, ∆S = 0
2. B∆U = 0, ∆S > 0
3. C∆U > 0, ∆S < 0
4. D∆U < 0, ∆S = 0

The best suitable method (sequence of reactions) to convert benzene into p-Chlorotoluene is:

1. A1. CH₃Cl / anhydrous AlCl₃ 2. CH₄ / H⁺
2. B1. Cl₂ / anhydrous AlCl₃ 2. CH₃Cl / anhydrous AlCl₃
3. C1. CH₃Cl / anhydrous AlCl₃ 2. Cl₂ / anhydrous AlCl₃
4. D1. CH₃Cl / H⁺ 2. conc. HCl

Oxidation state of Cr in Cr₂O₇²⁻ is:

1. A+2
2. B–2
3. C+6
4. D+7