Explanation

• AlCl₃ is the catalyst in Friedel–Crafts alkylation.
• It acts as a Lewis acid and generates the electrophile (R⁺).
• This electrophile attacks benzene ring in the reaction.

Last verified on 05-06-2026

Explanation

• Pure water can be obtained from seawater by distillation.
• Distillation separates water from dissolved salts and impurities.
• Seawater is heated to form water vapor.
• The vapor is then cooled and condensed into pure water.
• Therefore, distillation gives clean, salt-free water.

Last verified on 05-06-2026

Explanation

• K₂Cr₂O₇ (potassium dichromate) is an ionic compound, not a coordination complex.
• It contains Cr in an ionic lattice without ligands forming a complex ion.
• Transition metal complexes contain a central metal ion with ligands.
• K₄[Fe(CN)₆], K₃[Fe(CN)₆], and [Ni(H₂O)₆]SO₄ are all coordination (complex) compounds.

Last verified on 05-06-2026

Explanation

Glucose → Gluconic acid is oxidation of the aldehyde group at C-1 to a carboxylic acid.

Glucose: C₆H₁₂O₆, with an aldehyde -CHO at C1  

Gluconic acid: C₆H₁₂O₇, with -COOH at C1

In redox terms: R-CHO → R-COOH  

Carbon oxidation state goes from +1 in aldehyde to +3 in carboxylic acid.  

Change = +2 → loss of 2 e⁻

Reaction: C₆H₁₂O₆ + H₂O → C₆H₁₂O₇ + 2H⁺ + 2e⁻

So 2 electrons are involved in that oxidation.

Last verified on 05-06-2026

Explanation

• Xenon (Xe) is a noble gas and does not form complexes with EDTA.
• EDTA mainly reacts with divalent and trivalent metal ions

Common metal ions titrated by EDTA:

• Ca²⁺
• Mg²⁺
• Fe²⁺ / Fe³⁺
• Cu²⁺
• Ni²⁺

Last verified on 05-06-2026

Explanation

• In voltammetry, diffusion current is measured as a function of scanning potential difference.
• The potential is varied and current response is recorded.
• This method is used in electrochemical analysis.

Last verified on 05-06-2026

Explanation

• A precipitate forms when an insoluble compound is produced in a reaction.
• NaOH reacts with Fe(NO₃)₃ to form insoluble Fe(OH)₃.
• Fe(OH)₃ is a reddish-brown precipitate.
• So this pair produces a precipitate.

Last verified on 05-06-2026

Explanation

• Nickel (Ni) is the most active metal among the given options.
• It can displace lead (Pb) from its salt solution.
• Ag and Cu cannot displace Pb or Ni, showing lower reactivity.
• Therefore, Ni is the most reactive metal here.

Last verified on 05-06-2026

Explanation

• Precision refers to how close repeated measurements are to each other.
• It is related to consistency and reproducibility of data.
• It is NOT about closeness to the true value.
• Difference from true value defines accuracy, not precision.

Last verified on 05-06-2026

Explanation

• Thermoplastics soften on heating and harden on cooling.
• This process is reversible.
• They can be remoulded again and again.

Last verified on 05-06-2026