The acid - base equation between H2PO3^- and HS^- is H2PO3^- + HS^- ⇄S^- + H3PO3.
What is an acid?
An acid is a substance that can donate hydrogen ions while a base is a substance that can accept hydrogen ion. This is the acid base definition according to Brownstead - Lowry.
To show the acid - base relationship between H2PO3^- and HS^-, we have the equation;
H2PO3^- + HS^- ⇄S^- + H3PO3
Learn more about acids and bases: https://brainly.com/question/10282816
