Which gas is produced at the cathode during the electrolysis of acidified water? MCQ with Answer and Explanation

Explanation:
The thermite reaction involves aluminum powder reacting with iron(III) oxide to produce molten iron and aluminum oxide (2Al + Fe₂O₃ → Al₂O₃ + 2Fe). It is highly exothermic and is used for welding railway tracks and repairing metal structures in the field.

Explanation:
Copper is placed below hydrogen in the reactivity series, meaning it cannot displace hydrogen from dilute acids. Therefore, it does not react with dilute HCl. Mg, Fe, and Zn are above hydrogen in the series and react to release H₂ gas, forming their respective chlorides.

Explanation:
Fractional distillation is specifically designed to separate miscible liquids whose boiling points differ by less than 25 K. It uses a fractionating column which provides surfaces for repeated evaporation and condensation, enriching the vapor with the more volatile component before it reaches the condenser.