Urea is produced by the reaction of ammonia with: MCQ with Answer and Explanation

Explanation:
A decomposition reaction is one where a single compound breaks down into two or more simpler substances. Heating potassium chlorate (KClO₃) breaks it down into potassium chloride and oxygen gas. A is combination, C is displacement, and D is double displacement.

Explanation:
Using Boyle's law: P₁V₁ = P₂V₂ => 2 atm × 5 L = 1 atm × V₂ => V₂ = 10 L. As pressure decreases, volume increases. The same mass of gas expands. This is a direct application of inverse proportionality. If temperature and amount of gas are constant, doubling pressure halves volume, etc.

Explanation:
KCl (potassium chloride) is an ionic (electrovalent) compound formed by transfer of one electron from K to Cl, giving K⁺ and Cl⁻ ions held by electrostatic attraction. CH₄, CCl₄, CO₂ are covalent compounds with electron sharing. Electrovalent compounds have high melting points, conduct electricity in molten/aqueous state, and are generally soluble in water.