* Iron II sulfide (FeS) is a salt. Salts can be acidic, basic, or neutral.

* Blue litmus paper turns red in acidic solutions.

* Blue litmus paper turns blue in basic solutions.

* Blue litmus paper remains blue in neutral solutions.

To determine if FeS is acidic, basic, or neutral, we need to consider its hydrolysis reaction.

Hydrolysis of FeS:

FeS dissolves in water to a small extent, forming Fe²⁺ and S²⁻ ions. These ions react with water:

* Fe²⁺ is a weakly acidic cation, so it reacts with water to form H⁺ ions, making the solution slightly acidic.

* S²⁻ is a strongly basic anion, so it reacts with water to form OH⁻ ions, making the solution strongly basic.

Overall Effect:

Since S²⁻ is a stronger base than Fe²⁺ is an acid, the overall solution will be basic.

Therefore, blue litmus paper will turn blue in the presence of iron II sulfide (FeS).