Chemistry Flashcards

Which of the following reagents converts a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Answer: PCC (pyridinium chlorochromate)

PCC (pyridinium chlorochromate) is a mild oxidizing agent that oxidizes primary alcohols to aldehydes and stops there without forming carboxylic acids.

The crystal field splitting energy (Δo) is largest for which of the following ligands?

Answer: CN⁻

CN⁻ is a strong-field ligand at the top of the spectrochemical series, producing the largest crystal field splitting energy Δo.

In electrolysis of dilute H₂SO₄ solution, what is produced at the anode?

Answer: Oxygen gas

At the anode, water is oxidized (2H₂O → O₂ + 4H⁺ + 4e⁻) in dilute H₂SO₄ because O₂ is discharged in preference to SO₄²⁻.

Nylon-6 is produced by the polymerization of:

Answer: Caprolactam

Nylon-6 is produced by the ring-opening polymerization of caprolactam (a cyclic amide with 6 carbon atoms).

Which of the following is the correct IUPAC name for [Co(NH₃)₄Cl₂]Cl?

Answer: Tetraamminedichlorocobalt(III) chloride

In IUPAC nomenclature for coordination compounds, ligands are listed alphabetically (ammine before chloro), followed by the metal and its oxidation state, then the outer sphere ion.

Which of the following statements about entropy is correct?

Answer: Entropy decreases when a gas is dissolved in a liquid

When a gas dissolves in a liquid, the ordered arrangement increases (gas randomness is lost), so entropy decreases.

Which of the following is an example of a Cannizzaro reaction?

Answer: C₆H₅CHO + NaOH → C₆H₅COO⁻ + C₆H₅CH₂OH

Benzaldehyde (no α-hydrogen) undergoes Cannizzaro reaction with NaOH: one molecule is oxidized to benzoate and another is reduced to benzyl alcohol.