Answer:
CO.
Explanation:
Assuming the given percentages are by mass, we can solve this problem via imagining we have 100 g of the compound, if that were the case we would have:
Now we convert those masses into moles, using the elements' respective molar masses:
- 42.9 g of C ÷ 12 g/mol = 3.57 mol C
- 57.1 g of O ÷ 16 g/mol = 3.58 mol O
As the number of C moles and O moles is roughly the same, the empirical formula for the compound is CO.
