Explanation

Each CN⁻ has −1 charge, so 6 CN⁻ = −6

Overall charge is −4, so Fe = +2

Last verified on 19-05-2026

Explanation

• Dehydration means removal of water (H₂O) from an alcohol.
• Concentrated acid (like H₂SO₄) acts as a dehydrating agent.
• Tertiary alcohols easily form stable carbocations.
• Elimination leads to formation of an alkene.
• Tertiary butanol gives a substituted alkene as product.

Last verified on 19-05-2026

Explanation

• HBr reacts with alkanes/alkenes depending on conditions.
• In typical exam context, propane undergoes substitution (free radical reaction).
• Bromine replaces hydrogen at different positions.
• Secondary carbon is more stable than primary carbon.
• So major product follows stability rule.

Last verified on 19-05-2026

Explanation

• Solubility and rigidity depend on molecular structure and bonding.
• Flexible structures allow better interaction with solvent molecules.
• Increased flexibility generally improves solubility.
• More rigidity reduces molecular movement and solubility.

Last verified on 19-05-2026

Explanation

• Nylon 6,6 is a synthetic polyamide polymer.
• It is formed by condensation polymerization.
• Two monomers react to form long polymer chains.
• Nylon 6,6 is formed by condensation of adipic acid (diacid) and hexamethylenediamine (diamine).
• Each monomer contributes 6 carbon atoms (hence 6,6).
• Water is eliminated during the reaction.

Last verified on 19-05-2026

Explanation

• Polystyrene is a common synthetic polymer used in plastics and packaging.
• It is formed by addition polymerization.
• The repeating unit comes from a specific aromatic monomer.
• This monomer is called styrene (vinyl benzene).
• Hence, polystyrene is derived from styrene.

Last verified on 19-05-2026

Explanation

• Grignard reagents (RMgX) are strong nucleophiles.
• They react with carbon dioxide (CO₂) to form magnesium carboxylate.
• After acidic workup (H₃O⁺), carboxylic acid is produced.
• This is an important method to increase carbon chain length.
• It always forms acids after hydrolysis.

Last verified on 19-05-2026

Explanation

• Reaction spontaneity is determined by Gibbs free energy (ΔG).
• Formula: ΔG = ΔH − TΔS
• If ΔG is positive, reaction is non-spontaneous.
• If ΔG is negative, reaction is spontaneous.
• Here entropy is positive but not enough to overcome enthalpy.

Last verified on 19-05-2026

Explanation

• ΔTb = Kb × m × i = 0.512 × 0.5 × 1 = 0.256°C
• Boiling point = 100 + 0.256 = 100.256°C.

Last verified on 19-05-2026

Explanation

• The triple point is a special thermodynamic condition of a substance.
• At this point, all three phases exist together.
• These phases are solid, liquid, and gas.
• They remain in equilibrium at a specific temperature and pressure.
• It is a fixed and unique point for each substance.

Last verified on 19-05-2026