Acompound contains 69.94 percent iron and 30.06 percent oxygen. what is its molecular formula if the molar mass of the compound is 199.55 grams per mole?

The molecular formula is Fe₂O₃

Explanation:

The molar mass of the compound is 199.55 g/mol; this means that if we have 1 mol of the compound, we'd have 199.55 g, we'd also have:

Now we calculate the moles of each element present in the given masses, using their atomic masses:

Then in 1 mol of the compound, there's 2.50 mol Fe and 3.75 mol O:

We convert the coefficients into integers (Divide them by the lowest number among them and multiply them by two):

the correct answer would be b) volume versus temperature, because they are also directly proportional.