An electrochemical cell that converts chemical energy into electrical energy is called: MCQ with Answer and Explanation

Explanation:
Nickel (finely divided) catalyzes the addition of hydrogen to unsaturated vegetable oils to form solid vanaspati ghee. It provides surface for reaction. Platinum and palladium also work but are expensive. Iron is used in Haber process. V₂O₅ in Contact process.

Explanation:
Soap solution is basic, pH > 8.3, so it turns phenolphthalein pink. Lemon juice (citric acid) and vinegar (acetic acid) are acidic, pH < 7, phenolphthalein remains colorless. Hydrochloric acid is strongly acidic, colorless. Phenolphthalein indicator is colorless in acidic and neutral, pink in alkaline solutions. It is used in titrations.

Explanation:
Bakelite is a thermosetting plastic, heat resistant and electrical insulator. Polythene and PVC are thermoplastics; they soften on heating. Teflon is non-stick.