Question

In the reaction, h2po4 – + haso4 2– hpo4 2– + h2aso4 – , which two species act as acids?

Answer 1

Acids are substances capable of donating hydrogen ion H⁺. On left h2po4- is acid, because that ion donate one hydogen ion to haso42-, and on the right h2aso4- is acid, because donate one H⁺ to hpo42- (when hpo42- accept one hydrogen ion, he transorms in h2po4-).