Cu2O oxidul cupros Cu are valenta 1 ,O are valenta 2
MCu2O=2.64 +16=144 ACu=64 ,AO=16 A=masa atomica
Raport de atomi : 2Cu:1O
mCu:mO=2.64:16=128:16=8:1 se simplifica rapotrul prin 16
Compozitia proc.
144 gCu2O---------128 g Cu------------16 g O
100g Cu2O------------x-----------------------y
x=100.128:144=88,88 la suta Cu
y=100.16:144=11,11 la suta O
144 gCu2O------------------128 g Cu
400 g-------------------------a
a=400.128:144=355,5 g Cu
144g Cu2O-------------------128 g Cu
bgCu2O--------------------------------320g Cu
b=144.320:128=360 g Cu2O