Question

Which compound is soluble in water?(1) PbS (3) Na2S(2) BaS (4) Fe2S3

Answer 1

The compound Na2S or Sodium sulfide is soluble in water. This compound is a water-soluble salt that give strong alkaline solutions. When exposed to air or humidity this compound gives-off hydrogen sulfide that smells almost the same as rotten eggs.

This chemical is commonly used in the pulp and paper industry. Sodium sulfide compounds are usually used in chemical photography, textile bleaching, making dyes, and even detergents.

The other 3 compounds are non-soluble in water. Their compositions are mostly metal in nature and require other process to transform them into different compound forms. 

Answer 2

Answer;

(3) Na2S

Explanation;

• All sodium salts are soluble in water. Therefore, sodium sulfide will be soluble in water.  
• All sodium, potassium, and ammonium salts are soluble in water. The chlorides, bromides, and iodides of all metals except lead, silver, and mercury are also soluble in water.
• The sulfides of all metals except barium, calcium, magnesium, sodium, potassium, and ammonium are insoluble in water.