density= mass/volume
we need the volume of the metal to find the density, in which case the answer would be 64.2/volume=density
The molar mass of CuCl2 is 134.45 g/mol; therefore, you divide 2.5 g of CuCl2 by 134.45 g of CuCl2 leaving you with 0.019 moles
M=D*V
D=10.5 g/cm³
V=42.5 cm³
m= 10.5 g/cm³ * 42.5 cm³ ≈ 446 g
m≈446 g
Answer is in the image attached hope this helps!