Question

After calculating the empirical formula of a compound with 70.78% Fe and 22.22% O, what is its name?
A) Iron Oxide.
B) Ferrous Oxide.
C) Oxygen Ferrous.
D) Oxygen Iron.

Answer 1

Answer:

The correct answer is: B) Ferrous Oxide.

Explanation:

The empirical formula of a compound is the simplest whole-number ratio of the atoms of the elements that make up the compound. To calculate the empirical formula, we first need to find the molar mass of each element. The molar mass of iron is 55.845 g/mol and the molar mass of oxygen is 16.00 g/mol.

Next, we need to calculate the mass percent of each element in the compound. To do this, we divide the mass of each element by the total mass of the compound and multiply by 100%. The mass percent of iron is 70.78% and the mass percent of oxygen is 22.22%.

Now that we know the mass percent of each element, we can calculate the empirical formula. To do this, we divide the mass percent of each element by the atomic mass of the element and round to the nearest whole number. The empirical formula of the compound is FeO, which is also known as ferrous oxide.

Answer 2

To determine the empirical formula, you need to find the mole ratios. For the given percentages, the empirical formula is Fe₂O₃, which corresponds to iron(III) oxide. Therefore, the correct option is:

A) Iron Oxide.