Looking at the equation
CuO + 2HCl —> CuCl2 + H2O
For every 2 moles of HCl that react, 1 mole of CuCl2 is made.
As such, can you use this ratio to determine how many moles of CuCl2 will form when 0.50 moles of HCl completely react?
The relative atomic masses of Cu and Cl are 63.5 and 35.5, respectively. So what is the relative mass of CuCl2?
Multiply the moles of CuCl2 by its relative mass and you have your answer.