Răspuns:
M,CaO=56g/mol
A,Ca= 40g/mol
2mol 1mol 1mol sau, in grame
2Ca + O2------> 2CaO
2x40g......1mol.......2x56g
10g.............x................y
x= 10./80mol=...................calculeaza !!
y= 20x56/80g=................calculeaza !!
Explicație: