Question

Dau coroana!.....................
HELP!

Answer 1

CO2
C:O=1:2
mC:mO=12:2*16=12:32=3:8
3 g C +8 g O=11g CO2
3gC...............8g O............11gCO2
x g C..............y g O...........100g CO2
x=100*3/11=27.27% C
y=100*8/11=72.72% O

CaCO3
Ca:C:O=1:1:3
mCa:mC:mO=40:12:3*16=40:12:48=10:3:12
10g Ca+3g C+12g O=25g CaCO3
10g Ca..................3g C...............12g O............25g CaCO3
ag Ca.....................bgC................cgO...............100g CaCO3
a=40% Ca
b=12% C
c=48% O