Moles, compounds and formula


Find the empirical formulae and name each of the following compounds.


1)     A black powder is made of 63.2% Mn and 36.8%O.

2)     A dark red powder has the composition Fe - 70%, O - 30%,

3)     A colourless liquid, contains 52.2%C, 13.0%H and 34.8%O

4)     A white powder is Na 27.4%, H 1.2%, C 14.3% and O 57.1 %.

5)     An oily liquid that can eat away paper contains 2.1%H, 65.4%O and 32.5%S