Which compound is soluble in water? (1) pbs (3) na2s(2) bas (4) fe2s3

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. 

The correct answer would be 1. precipitation

Because a model would make the investigation easier to understand