a, CTDC: CxOy
Có: x:y=\(\dfrac{42,8}{12}:\dfrac{57,2}{16}\)
=3,57:3,575
=1:1
=>x=1;y=1
CTHH:CO
b, Ta có CTHC MnxOy
%O = 100 - 48,6 = 51,4 %
x : y = \(\dfrac{48,6}{55}\) : \(\dfrac{51,4}{16}\)
x : y = 0,884 : 3,2125
x : y = 1 : 4
=> CTHC là MnO4