The alloy brass is composed of: MCQ with Answer and Explanation

Explanation:
Hydrogenation is the addition of hydrogen to unsaturated compounds (like alkenes or alkynes) in the presence of a catalyst (like Ni, Pd, or Pt) to form saturated compounds (alkanes). For example, ethene + H₂ → ethane. This process is widely used in the food industry to solidify vegetable oils.

Explanation:
Rusting is an electrochemical process requiring both oxygen and water (moisture). The overall reaction: 4Fe + 3O₂ + 2xH₂O → 2Fe₂O₃·xH₂O. In the absence of either, rusting does not occur. Salt accelerates rusting by increasing conductivity. Prevention methods include painting, greasing, galvanization, and cathodic protection. Rust is hydrated iron(III) oxide, a reddish-brown flaky substance, not protective.

Explanation:
A separating funnel allows immiscible liquids to form layers; the denser liquid is drained from the bottom. Fractionating column is for miscible liquids with close boiling points, condenser for distillation, centrifuge for separating fine solids or liquids of different densities by spinning.