Explanation

• When a chemical cell’s voltage becomes zero, the reaction has reached equilibrium.
• At this point, no net electron flow occurs.
• The rates of forward and reverse reactions become equal.
• Hence, no potential difference is produced.

Last verified on 05-06-2026

Explanation

• Natural rubber consists of polymers of isoprene (C₅H₈).
• Isoprene is a five-carbon unsaturated hydrocarbon.
• Natural rubber is chemically known as cis-1,4-polyisoprene.
• It is obtained from the latex of rubber plants.

Last verified on 05-06-2026

Explanation

• Magnetic susceptibility (χ) is measured using both Gouy balance and Faraday balance.
• These instruments determine the magnetic behavior of substances.
• They are commonly used for paramagnetic and diamagnetic materials.

Last verified on 05-06-2026

Explanation

CH₃Br molecular ion peaks come from bromine isotopes.  

Br has 2 stable isotopes: ⁷⁹Br ≈ 50.7% and ⁸¹Br ≈ 49.3% → basically 1:1 ratio

So CH₃Br gives 2 M⁺ peaks:  

1) ¹²C + 3(¹H) + ⁷⁹Br = 12 + 3 + 79 = m/z 94

2) ¹²C + 3(¹H) + ⁸¹Br = 12 + 3 + 81 = m/z 96

Because the isotopes are ~equal in nature, the two peaks are equal size/height.

Last verified on 05-06-2026

Explanation

• At constant volume, ΔE = q.
• No work is done because volume does not change.
• Therefore, all heat supplied changes the internal energy.
• This follows the First Law of Thermodynamics.

Last verified on 05-06-2026

Explanation

• SF₆ has F–S–F bond angles of 90° and 180°.
• It has an octahedral geometry.
• Six fluorine atoms are arranged symmetrically around sulfur.
• Adjacent F atoms make 90°, opposite F atoms make 180°.

Last verified on 05-06-2026

Explanation

• Fe³⁺ has the greatest magnetic moment among the given ions.
• Magnetic moment depends on the number of unpaired electrons.
• More unpaired electrons mean stronger paramagnetism.
• Fe³⁺ contains 5 unpaired electrons.

Last verified on 05-06-2026

Explanation

• In Na₄[Co(C₂O₄)₃], cobalt has coordination number 6.
• Each oxalate (C₂O₄²⁻) is a bidentate ligand.
• Three oxalate ligands provide 6 coordination sites.
• Oxidation state of Co is +3.

Last verified on 05-06-2026

Explanation

• SO₂ is a polar molecule.
• It has a bent (angular) shape which creates dipole moment.
• The dipole moments do not cancel each other.
• Therefore, it shows a net dipole moment (5.33 × 10⁻³⁰ cm given).

Last verified on 05-06-2026

Explanation

Use Graham’s Law of effusion: rate ∝ 1/√M  

And time ∝ √M since time = 1/rate

t₂ / t₁ = √(M₂ / M₁)

Molar mass: He = 4 g/mol, O₂ = 32 g/mol  

t_He = 5 s

t_O₂ = 5 × √(32 / 4) = 5 × √8 = 5 × 2.828 ≈ 14.1 s.

Last verified on 05-06-2026