To determine the strength of acids based on their molecular composition, we can consider their behavior in water (their ability to donate protons, H⁺).
- HCl (hydrochloric acid) is a strong acid that dissociates completely in water, making it the strongest among the three.
- H2S (hydrosulfuric acid) is a weak acid compared to HCl but is still stronger than PH3.
- PH3 (phosphine) does not act as an acid in water, making it the weakest of the three.
Therefore, the correct order from strongest to weakest acid is:
HCl, H2S, PH3
So the correct response is: HCl, H2S, PH3