Answer:

Explanation:
Hello there!
In this case, since these problems about formulas, firstly require the determination of the empirical formula, assuming that the given percentages are masses, we can calculate the moles and mole ratio of oxygen to iron as shown below:

In such a way, by rounding to the first whole number we multiply by 8 and divide by 5 to obtain:

Whose molar mass is 159.69 g/mol and the mole ratio of the molecular to the empirical formula is:
479.1/159.69=3
Therefore, the molecular formulais:

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Answer:
160.3g
Explanation:
We know the equation:
No of moles = mass ÷ Mass of element
We need to find the mass, so make mass the subject of the formula.
Mass = No. of moles × mass of element
Mass = 5 × 32.06
Mass = 160.3g
Answer:
Refer to the period table. Use the atomic mass for calculation. Multiply the atomic mass with the number of atoms. For example, Al2(SO4)3. (27 × 2) + (32 x 3) + (16 x 12) = molecular mass