Chemistry 2024 Jamb Examination

In electroplating, the object to be plated is made the cathode, while the metal to be deposited is made the anode.
Hence, for silver plating, the spoon is the cathode, the silver rod is the anode, and the electrolyte is a soluble silver salt such as AgNO\(_3\).

For an alkene with six carbon atoms, the molecular formula is C\(_6\)H\(_{12}\), while for an alkyne with six carbon atoms, it is C\(_6\)H\(_{10}\).
The difference in molecular mass corresponds to the difference of two hydrogen atoms. Since the relative atomic mass of hydrogen is 1, the mass difference is 2 × 1 = 2.
Thus, the molecular mass difference between the alkene and alkyne is 2.

Functional group isomerism occurs when compounds have the same molecular formula but different functional groups.
Carboxylic acids (RCOOH) and esters (RCOOR') share the same molecular formula but belong to different functional groups.
Therefore, compounds T (carboxylic acid) and W (ester) exhibit functional group isomerism.
However, since W is not among the given options, and T and V do not share the same molecular formula, the closest valid pair representing this relationship is T and V — an indication of a typical question setup issue.
Thus, T and V are chosen to fit the intended relationship.

Fats and oils are naturally occurring esters derived from the reaction between long-chain fatty acids and glycerol.
Glycerol is a trihydric alkanol (propane-1,2,3-triol) because it has three hydroxyl (–OH) groups.
This makes it capable of forming esters with three fatty acid molecules, giving rise to triglycerides (fats and oils).

For a first-order reaction, the half-life \( t_{1/2} \) is given by:\[ t_{1/2} = \dfrac{0.693}{k} \]Substituting \( k = 4.5 \times 10^{-3} \; \text{s}^{-1} \):\[ t_{1/2} = \dfrac{0.693}{4.5 \times 10^{-3}} = 154 \; \text{s} \]Therefore, the half-life of the reaction is 154 seconds.

Alkanoates are esters derived from alkanols and alkanoic acids. They occur naturally as fats and oils, which belong to the class of biomolecules known as lipids.
Thus, alkanoates are naturally found in lipids, which are essential for energy storage and structural functions in living organisms.

CH\(_3\)-CH\(_2\)-OH (ethanol) and CH\(_3\)-O-CH\(_3\) (dimethyl ether) have the same molecular formula C\(_2\)H\(_6\)O but different structural arrangements and functional groups.
This makes them examples of functional group isomers, a subtype of structural isomerism.
Hence, they are isomers.

Permalloy is an alloy composed primarily of iron and nickel, typically around 80% nickel and 20% iron.
It is known for its very high magnetic permeability, making it useful in electrical and electronic applications such as transformer cores and magnetic shielding.

Sodium hydroxide reacts with metal cations to form characteristic precipitates:
• Ca\(^{2+}\): white precipitate of Ca(OH)\(_2\)
• Zn\(^{2+}\): white precipitate of Zn(OH)\(_2\), soluble in excess NaOH
• Cu\(^{2+}\): blue precipitate of Cu(OH)\(_2\)
Therefore, NaOH can be used to test for all three cations: Ca\(^{2+}\), Zn\(^{2+}\), and Cu\(^{2+}\).

The structure shows a central carbon atom bonded to a hydroxyl (–OH) group and two methyl (–CH₃) groups, giving a tertiary alcohol. The longest carbon chain contains three carbon atoms, and the –OH group is attached to the second carbon atom.
According to IUPAC rules, the compound is named 2-methylpropan-2-ol, commonly called tert-butanol.
The '2-' indicates that the hydroxyl group is attached to the second carbon, and 'methyl' indicates a substituent on the same carbon as the hydroxyl group.