The reaction between an acid and a base to form salt and water is: MCQ with Answer and Explanation

Explanation:
Ethylene glycol (1,2-ethanediol) is the main component of antifreeze, lowering the freezing point of water. Methanol is toxic, ethanol can be used but evaporates, glycerol is viscous. Ethylene glycol is poisonous if ingested. Propylene glycol is a safer alternative.

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:
Cooking of food involves chemical reactions (e.g., denaturation of proteins, caramelization of sugars) that form new substances, making it a chemical change. Dissolving sugar in water is a physical change because no new substance is formed (sugar can be recovered by evaporation). Breaking glass is a physical change (change in size/shape). Melting wax is a physical change (change of state).