# How does the pH of acid change when a carbonate is added?

Carbonates will (partly) neutralize the acid, so $p H$ goes up.
$2 {H}_{3} {O}^{+} \left(a q\right) + C {O}_{3}^{2 -} \left(a q\right) \to 3 {H}_{2} O \left(l\right) + C {O}_{2} \left(g\right)$
or: $2 {H}^{+} \left(a q\right) + C {O}_{3}^{2 -} \left(a q\right) \to {H}_{2} O \left(l\right) + C {O}_{2} \left(g\right)$