Isotopes of an element have: MCQ with Answer and Explanation

Explanation:
Sulphuric acid is a key reagent in many processes: to produce HCl from NaCl, HNO₃ from nitre, fertilizers (superphosphate), and in petroleum refining, pickling, etc. It is also used as a dehydrating agent and catalyst. Ammonia is made by Haber process without H₂SO₄. NaOH is made by electrolysis of brine. H₂SO₄ is known as 'king of chemicals'.

Explanation:
The salt bridge (often KCl-agar) allows ion migration to maintain electrical neutrality in half-cells, completing the circuit. It prevents direct mixing of electrolytes.

Explanation:
Hydrogen has about 150 kJ/g (highest). Petrol ~47 kJ/g, coal ~25-35 kJ/g, cow dung cake ~8 kJ/g. Hydrogen produces only water on combustion and is a clean fuel.