Which of the following metals reacts with steam but not with cold water? MCQ with Answer and Explanation

Explanation:
Baking soda is sodium hydrogen carbonate (NaHCO₃). It is used as a leavening agent in baking (produces CO₂ upon heating or with acid), as an antacid, and in fire extinguishers. Sodium carbonate (Na₂CO₃) is washing soda. Calcium carbonate is limestone/marble. Potassium carbonate is potash. Baking powder is a mixture of NaHCO₃ and a weak acid like tartaric acid.

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:
Highly reactive metals (K, Na, Ca, Mg, Al) are extracted by electrolysis of their fused (molten) salts because chemical reducing agents cannot reduce their ores. For sodium, Down's process: electrolysis of molten NaCl with CaCl₂ to lower melting point. Iron is extracted by smelting (blast furnace). Copper and zinc can be extracted by reduction with coke or electrolytic refining of impure metal.