Explanation

• Atoms are made of protons, neutrons, and electrons.
• Protons and neutrons are heavy particles located in the nucleus.
• Electrons are very light compared to protons.
• Electron mass is almost negligible in atomic calculations.
• That is why electron is considered the lightest fundamental particle in this context.

Last verified on 22-05-2026

Explanation

• Transition metal compounds show color due to electronic transitions.
• In copper compounds (especially Cu²⁺), d-orbitals are partially filled.
• Electrons absorb specific wavelengths of light and get excited between d-orbitals.
• The remaining reflected/transmitted light appears blue.
• This phenomenon is called d–d transition.

Last verified on 20-05-2026

Explanation

• Ozonolysis breaks the double bond of alkenes using ozone (O₃).
• Propene has structure: CH₃–CH=CH₂.
• Double bond cleavage forms two carbonyl compounds.
• One side gives ethanal (CH₃CHO) and the other gives methanal (HCHO).
• Therefore, these are the final products after ozonolysis.

Last verified on 20-05-2026

Explanation

• Alkyl benzene undergoes side-chain oxidation to form benzoic acid.
• A strong oxidizing agent is required for this conversion.
• Potassium permanganate (KMnO₄) in acidic medium is commonly used.
• It converts the alkyl side chain completely into –COOH group.
• Example: Toluene → Benzoic acid.

Last verified on 20-05-2026

Explanation

• Gabriel phthalimide synthesis is a method to prepare amines.
• It involves alkylation of phthalimide followed by hydrolysis.
• This method specifically gives only primary amines.
• It avoids formation of secondary and tertiary amines.
• Therefore, it is a selective and controlled preparation method.

Last verified on 20-05-2026

Explanation

• Rate law shows how reaction rate depends on reactant concentrations.
• If rate does NOT change when B changes, then B has no effect on rate.
• This means the order of reaction with respect to B is zero.
• So B appears with exponent 0 in the rate law.
• Therefore, rate depends only on A.

Last verified on 20-05-2026

Explanation

• Nitrobenzene (C₆H₅NO₂) is reduced to aniline (C₆H₅NH₂).
• Reduction requires removal of oxygen and addition of hydrogen.
• Common lab method uses metals in acidic medium.
• Iron (Fe) with hydrochloric acid (HCl) is widely used (Béchamp reduction).
• It efficiently converts nitro group (–NO₂) to amino group (–NH₂).

Last verified on 20-05-2026

Explanation

• Spontaneity of any reaction depends on Gibbs free energy (ΔG).
• Endothermic reaction absorbs heat, but can still be spontaneous.
• The key condition for spontaneity is that free energy must decrease.
• This happens when system moves to a more stable state.
• So ΔG must be negative.

Last verified on 20-05-2026

Explanation

• Quantum numbers must follow fixed rules.
• For a given principal quantum number n, azimuthal quantum number l = 0 to (n−1).
• If n = 3, possible l values are 0, 1, 2 only.
• So l = 3 is not allowed for n = 3.
• Therefore that set is invalid.

Last verified on 20-05-2026

Explanation

For l=2, it represents the d-subshell.

A d-subshell has 5 orbitals, and each orbital can hold 2 electrons.

So total electrons = 5 × 2 = 10.

Last verified on 20-05-2026