The balanced chemical equation for the reaction between a weak acid (H₂S) and a strong base (KOH) is:
H₂S(aq) + KOH(aq) → KHS(aq) + H₂O(l)
In this reaction, the potassium ion (K⁺) from the base combines with the hydrogen sulfide ion (HS⁻) from the acid to form potassium hydrosulfide (KHS). The hydroxide ion (OH⁻) from the base combines with a hydrogen ion (H⁺) from the water molecule to form a water molecule (H₂O).