Răspuns:
100g CuCO3................80g CuCO3 pur
150g CuCO3..................xg CuCO3 pur
x=150x80/100=120g CuCO3 pur
MCuCO3=64x32,3x16=124g/mol
MCuO=64+16=80g/mol
124g...............80g
CuCO 3 → CuO + CO2↑
120g.............yg
y=120x80/124=calculeaza
Explicație: