Răspuns:
1.
100gCaCO3.........85gpur
500gCaCO3........xgpur
x=500×85/100=425g CaCO3 pur
MCaCO3 =40+12+3×16=100g/mol
MCaO=40+16=56g/mol
100g 56g
CaCO3 => CaO + CO2
425g xg
x=425×56/100=calculează .
2.
MH2 =2×1=2g/mol
MNH3 =14+3×1=17g/mol
3×2g 2×17g
N2+ 3H2=> 2NH3
24g xg
x=24×2×17/3×2=calculează