According to the valence number of copper(2+) and the same value for chlorine (1-) copper (II) chloride has the formula of CuCl2
The molar mass of copper is 0,0635 kg/mole and chlorine gas a molar mass of 0,035 kg/mole the compound will have a molar mass of ( 0,0635+2×0,035 )kg/mole=0,099kg/mole and 0,344 moles are equivalent in mass to 0,344×0,135 kg=0,046 kg
