Chemistry
Assertion (A): Hydraulic washing is a method to separate impurities from the ore.
Reason (R): In Hydraulic washing, denser particles float and lighter particles settle down.
- Both (A) and (R) are true and (R) is the correct explanation of (A).
- Both (A) and (R) are true and (R) is not the correct explanation of (A).
- (A) is true but (R) is false.
- (A) is false but (R) is true.
Answer
(A) is true but (R) is false.
Reason — Hydraulic washing (gravity separation) is a method to separate impurities (gangue) from the ore. Hence, the assertion (A) is true.
During the hydraulic washing, denser particles settle at the bottom whereas lighter particles float on the surface. Hence, the reason (R) is false.
Related Questions
A white precipitate is formed when dilute hydrochloric acid reacts with ‘X’. The white precipitate is soluble in excess of NH4OH and insoluble in dilute HNO3. Identify ‘X’.
- AgNO3
- NH4Cl
- AgCl
- CaCl2
Assertion (A): In a solution containing equal concentration of Cu2+ ions and Ca2+ ions, Cu2+ ions will be discharged in preference to Ca2+ ions.
Reason (R): Ca2+ ions are placed above Cu2+ ions in the electrochemical series.
- Both (A) and (R) are true, and (R) is the correct explanation of (A).
- Both (A) and (R) are true, and (R) is not the correct explanation of (A).
- (A) is true but (R) is false.
- (A) is false but (R) is true.
The oxide which reacts with both dilute hydrochloric acid and sodium hydroxide solution to form salt and water is:
- Basic oxide
- Amphoteric oxide
- Acidic oxide
- Neutral oxide
Which of the following will occupy the volume 2.8 litres at S.T.P.?
(Atomic weight: C = 12, O = 16, Cl = 35.5, S = 32)- 2 moles of carbon dioxide
- 7.1 g of chlorine
- 8 g of sulphur dioxide
- 56 g of carbon monoxide