Copper bromide and sodium sulfate react to form copper sulfate and sodium bromide. The reaction can be represented by the following equation:

CuBr2 + Na2SO4 → CuSO4 + 2NaBr

This reaction is a double displacement reaction, in which the positive and negative ions of the two compounds switch places. The copper ions in copper bromide combine with the sulfate ions in sodium sulfate to form copper sulfate, while the sodium ions in sodium sulfate combine with the bromide ions in copper bromide to form sodium bromide.