Răspuns:
Al2O3
a) raport atomic Al:O=2:3
B) raport de masa Al:O=54:48=9:8
c) MAl2O3=2x27+3x16=102g/mol
102g Al2O3.....................54gAl...............48gO
100gAAl2O3....................x%Al..................y%O
x=100x54/102=calculeaza
y=100x48/102=calculeaza
d) 102gAl2O3....................48gO
204gAl2O3.........................xgO
x=204x18/102=calculeaza
e) 102g Al2O3..................54gAl
zgAl2O3.............................81gAl
z=102x81/54=calculeaza
Explicație: