Question

..Calculați compoziția procentuală : 1)Clorura de calciu
2) Oxid de aluminiu
3)Apa

Answer 1

CaCl2
MCaCl2=ACa+2×ACl=40+2×35,5=111g
111gCaCl2.............40gCa.......71gCl
100gCaCl2.............xgCa..........ygCl
x=100×40/111=calculeaza
y=100×71/111=calculeaza
Al2O3
MAl2O3=2×AAl+3×AO=2×27+3×16=54+48=102g
102gAl2O3........2×27gAl........3×16gO
100gAl2O3.......xgAl.................ygO
x=100×2×27/102=calculeaza
y=100×3×16/102=calculeaza
H2O
MH2O=2×AH+AO=2×1+16=18g
18gH2O......2gH......16gO
100gH2O....xgH........ygO
x=100×2/18=calculeaza
y=100×16/18=calculeaza