Question

Study the following observation and name the anion present in the reaction:

When few drops of dilute sulphuric acid is added to Salt 'R' and heated, a colourless gas is released which turns moist lead acetate paper silvery black.

Answer 1

The observation indicates that the gas released reacts with lead acetate paper, turning it silvery black. This suggests the presence of hydrogen sulfide (H₂S) gas, which reacts with lead acetate to form lead sulfide (PbS), a black precipitate.

Sulphide (S^2-)