The salt produced when copper oxide (CuO) reacts with hydrochloric acid (HCl) is copper(II) chloride (CuCl₂).

Here's the balanced chemical equation for the reaction:

CuO (s) + 2HCl (aq) → CuCl₂ (aq) + H₂O (l)

This reaction is a classic example of a neutralization reaction where a metal oxide reacts with an acid to form a salt and water.