WAEC - Chemistry (2019 - No. 27)
What is the characteristic of the gas liberated when dilute hydrochloric acid is added to Iron(ii)sulphide?
turns lime water milky
decolorizes bromine water
gives a pop sound
turns lead(ii)ethanoate paper black
Paliwanag
- Iron sulfide reacts with hydrochloric acid, releasing hydrogen sulfide: FeS + 2HCl → FeCl\(_2\) + H\(_2\)S.
- Hydrogen sulfide reacts with lead acetate to form lead sulfide and thus produces a coloration on the paper which will vary from yellow to black, depending upon the amount of hydrogen sulfide present.