Detennine the empirical formula of an oxide of iron which has `69.9%` iron and `30.1%` dioxygen by mass.

Explanation

To determine the empirical formula of an oxide of iron with given percentages of iron and oxygen, we can follow these steps:

### Step 1: Assume a 100 g Sample
Assuming we have a 100 g sample of the oxide, we can directly convert the percentages into grams:
- Mass of Iron (Fe) = 69.9 g
- Mass of Oxygen (O) = 30.1 g

### Step 2: Calculate Moles of Iron and Oxygen
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