Faraday's second law: When same charge is passed, masses deposited are proportional to: MCQ with Answer and Explanation

Explanation:
CH₄ + 2O₂ → CO₂ + 2H₂O + heat. Complete combustion of any hydrocarbon with sufficient oxygen always produces carbon dioxide and water. Incomplete combustion due to limited oxygen produces carbon monoxide (CO) and/or soot (carbon particles). Methane is the main component of natural gas and biogas. CO is a poisonous gas. The combustion of alkanes is highly exothermic.

Explanation:
Sodium and potassium are highly reactive alkali metals that react vigorously with oxygen and moisture in the air, potentially catching fire. To prevent accidental fires, they are stored immersed in kerosene oil. Magnesium and calcium do not require such extreme storage conditions.

Explanation:
Diamond has a three-dimensional network of strong covalent bonds between carbon atoms (sp³ hybridization). This giant covalent structure gives diamond its extreme hardness, high melting point, and electrical insulating property. Graphite also has covalent bonds within layers but conducts due to delocalized electrons. Ionic bonds are in NaCl, metallic bonds in metals, hydrogen bonds in water.