Hydrogen peroxide is a: MCQ with Answer and Explanation

Explanation:
In a Daniel cell, the anode (where oxidation occurs) is a zinc rod immersed in ZnSO₄ solution. The cathode is a copper rod in CuSO₄ solution. Zinc is more reactive, so it loses electrons (Zn → Zn²⁺ + 2e⁻) and acts as the negative terminal of the cell.

Explanation:
Rate of diffusion is inversely proportional to the square root of molar mass (Graham's law). Lighter gases diffuse faster. Molar masses: NH₃ = 17, N₂ = 28, O₂ = 32, CO₂ = 44 g/mol. Therefore NH₃ has the lowest molar mass and diffuses fastest. This law also explains why the smell of perfume spreads quickly. NH₃ is lighter than air and would rise.

Explanation:
Solder is an alloy primarily used for welding electrical components and pipes. It is traditionally composed of lead (Pb) and tin (Sn), typically in a 60:40 or 50:50 ratio. Brass is copper and zinc, bronze is copper and tin, and duralumin is an alloy of aluminum, copper, magnesium, and manganese.