Răspuns:
1 NaOH
MNaOH=23+16+1=40g/mol
40gNaOH.................23gNa...............16gO................1gH
100gNaOH...................xgNa..............ygO........ .......zgH
x= 100×23/40= calculeaza
y=100×16/40= calculeaza
z= 100×1/40= calculeaza
2. CaCO3
MCaCO3=40+12+3×16=100g/mol
100g MgCO3...................40gCa.............12gC..................48gO
100gMgCO3...................xgCa..................ygC..................zgO
x=100×40/100= calculeaza
y=100×12/100= calculeaza
z=100×48/100= calculeaza
Explicație: