The chemical process used for extracting a metal from its ore by dissolving it in a suitable reagent is called:
A. Smelting
B. Calcination
C. Leaching
D. Roasting
Answer: Option C
Solution (By JKExamLibrary)
Leaching is a chemical method of concentration where the powdered ore is treated with a suitable reagent that dissolves the ore but not the impurities. Calcination and roasting are thermal processes, and smelting involves reduction with a chemical reducing agent like carbon at high temperatures.
Explanation:
A lead-acid battery, commonly used in automobiles, consists of lead anodes and lead dioxide cathodes. The electrolyte used is an aqueous solution of sulfuric acid (H2SO4). During discharge, the acid is consumed to form lead sulfate and water, decreasing the density of the electrolyte.
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. VāOā in Contact process.
Explanation:
J.J. Thomson proposed the 'Plum Pudding' model in 1904 after discovering the electron. He envisioned the atom as a sphere of positive charge with negatively charged electrons embedded within it, like plums in a pudding. This was later disproved by Rutherford's gold foil experiment.
No comments yet. Be the first to start the discussion!