640g x y
2 Cu +O2=2CuO MCuO=64+16=80
2.64 32 2.80
x=640.32:2.64=160gO2 1mol O2---------32 gO2
a moli-----------160g
a=160.1:32=5 moli O2
800 b
CuO+2HCl=CuCl2 +H2O
80 2.36,5
y=640.2.80:2.64=800g CuO
b=800.2.36,5:80=730 g HCl acesta este md solutiei
c=md.100:ms ms=md.100:c
ms=730.100:36,5=2000 g sol. HCl