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.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true and (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (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:

1. Basic oxide
2. Amphoteric oxide
3. Acidic oxide
4. Neutral oxide

A salt solution which gives a reddish-brown precipitate with NaOH and a white precipitate with BaCl₂ solution is:

1. CuSO₄
2. Ca(NO₃)₂
3. Fe₂(SO₄)₃
4. FeCl₃

An alkane with molecular mass 44 is:

1. CH₄
2. C₃H₈
3. C₄H₁₀
4. C₂H₆