Answer:
Mn₁O₂
Explanation:
To find the empirical formula, you need to (1) determine how many grams of each element are within the compound, then (2) convert grams to moles (via the atomic masses of each element), and then (3) determine the mole-to-mole ratio of each element.
(Step 1)
Because the percents add to equal 100%, we can say that each percent is the mass of each element.
63% Mn ----> 63 grams Mn
37% O ----> 37 grams O
(Step 2)
We need to convert each mass to moles using the atomic masses. The atomic masses are a ratio comparing the mass of each element per every 1 mole.
Atomic Mass (Mn): 54.983 g/mol
Atomic Mass (O): 15.998 g/mol
63 grams Mn 1 mole
---------------------- x ------------------------- = 1.15 moles Mn
54.983 grams
37 grams O 1 mole
-------------------- x ------------------------ = 2.31 moles O
15.998 grams
(Step 3)
You can find the mole-to-mole ratio of each element in the compound by dividing the calculated mole values by the smallest mole value. In this case, since 1.15 moles was the smallest value calculated, it should be the divisor. The resulting amounts are the subscripts within the empirical formula.
1.15 moles Mn / 1.15 moles = 1 moles Mn
2.31 moles O / 1.15 moles = 2 moles O
Ratio of MnO = 1:2
This make the empirical formula: Mn₁O₂
