Which polymer is used to make non-stick kitchen utensils? MCQ with Answer and Explanation

Explanation:
2NaHCO₃ (heat) → Na₂CO₃ + CO₂ + H₂O. This is used in baking as CO₂ causes dough to rise. The sodium carbonate formed gives a bitter taste if excess soda is used, hence baking powder (with acid) is preferred.

Explanation:
Aluminium goes from 0 to +3 oxidation state (Al → Al³⁺ + 3e⁻), so it is oxidized. Iron goes from +3 to 0 (Fe³⁺ + 3e⁻ → Fe), reduced. This is a thermite reaction, highly exothermic, used for welding. Al is the reducing agent, Fe₂O₃ is the oxidizing agent. Oxidation is loss of electrons.

Explanation:
Phenolphthalein is colorless in acidic and neutral solutions, turning pink/magenta in basic solutions with pH > about 8.2-10. It is commonly used in acid-base titrations. Methyl orange is red in acidic and yellow in basic. Litmus is purple in neutral, red in acid, blue in base. Natural indicators like turmeric, beetroot also show color changes.