m,impur=2g
p=80%
p/100= m,p/m,i----> m,p=1,6g Ca
Ca+1/2O2--->CaO
CaO+ H2O---> Ca(OH)2
1 mol var stins se obtine din 1 mol Ca
(40gCa+2gH+2x16gO)..................................40g
x.........................................................................1,6
calculeaza !!!!!!