The rotten-egg odor sometimes noticed in acidic wastewater treatment is due to…
CHEMISTRY · Multi-part · AP · Chemistry · Chemical Reactions · Chemical Reactions
Problem
The rotten-egg odor sometimes noticed in acidic wastewater treatment is due to gaseous hydrogen sulfide produced according to the net ionic equation
S2−(aq)+2H+(aq)→H2S(g).
A chemist has access to the following reagents:
• sodium sulfide solution
• 6.0 M hydrochloric acid
• 6.0 M nitric acid
• sodium nitrate solution
Answer all parts below.
(a) Choose reagents from the list that will generate the reaction represented by the net ionic equation when mixed. Write a balanced molecular equation for the reaction, including physical states.
(b) Write the complete ionic equation for the reaction in part (a) and identify the spectator ions.
(c) Hydrogen sulfide escapes from solution as a gas. Explain how this physical change drives the reaction to completion, even though one of the products is a weak electrolyte.
(d) Replace hydrochloric acid with nitric acid in the reaction and predict whether the net ionic equation will remain the same. Write the new molecular equation and justify any difference in the identity of spectator ions.