Chemistry
Chemistry
Problem
A compound that contains only nitrogen and oxygen is found to be 69.6 % oxygen by mass. Which of the following is the empirical formula of the compound? a) b) c) d)Intuitive explanation
The key is converting mass percentages into a mole ratio. Since the compound is 69.6% oxygen, it's 30.4% nitrogen—use these percentages as if you had 100 g of sample, then divide each mass by its element's molar mass to find moles. The smallest whole-number ratio of moles gives you the empirical formula, which represents the simplest repeating unit of the compound.
Intuitive explanation
The key is converting mass percentages into a mole ratio. Since the compound is 69.6% oxygen, it's 30.4% nitrogen—use these percentages as if you had 100 g of sample, then divide each mass by its element's molar mass to find moles. The smallest whole-number ratio of moles gives you the empirical formula, which represents the simplest repeating unit of the compound.