Answer:
this is soloution of example ..
When the substance is said to be an oxide of iron, that means the compound contains elements of Fe and O. Suppose you have 100 g of the sample.
Mass of Fe = 72.36 g
Mass of O = 100 - 72.36 = 27.64 g
The molar mass of Fe is 55.8 g/mol while the molar mass of O is 16 g/mol.
Moles of Fe = 72.36/55.8 = 1.29677
Moles of O = 27.64/16 = 1.7275
Now, divide both amounts by the lower number, which is 1.29677.
Fe: 1.29677/1.29677 = 1
O = 1.7275/1.29677 = 1.333
The answer must be whole numbers. So, let's try multiplying the least number to O that would make it a whole number. That would be 3.
Fe: 1*3 = 3
O: 1.333*3 = 4
<em>Thus, the empirical formula is Fe₃O₄.</em>
In the compound Co2O3, cobalt has an oxidation number of 3, while oxygen's oxidation number is -2.
An oxidation number is a number assigned to an element in chemical combination that represents the number of electrons lost (or gained, if the number is negative) by an atom of that element in the compound.