The process of separating ammonium chloride from a mixture of ammonium chloride and salt uses: MCQ with Answer and Explanation

Explanation:
Oxidation is the gain of oxygen or loss of electrons. Here, Carbon (C) gains oxygen to form Carbon dioxide (CO₂), so Carbon is oxidized. Lead oxide (PbO) loses oxygen to form Lead (Pb), so PbO is reduced. This is a classic redox reaction where both processes occur simultaneously.

Explanation:
Biofuels, such as bioethanol and biodiesel, are derived from recent biological materials (biomass) and can be replenished, making them renewable. Biodiesel is specifically produced through transesterification, a chemical reaction where vegetable oils or animal fats react with an alcohol (like methanol) to form fatty acid methyl esters.

Explanation:
A positive catalyst increases reaction rate by lowering activation energy. Decreasing temperature generally slows reactions. Decreasing concentration reduces collision frequency, lowering rate. Larger pieces have less surface area, slower reaction. Other rate-increasing factors: increasing temperature, increasing pressure (for gases), using finely powdered solids, and light for photochemical reactions.