To figure out empirical formulas using mass percentages, you start by changing those percentages into grams.
Let's say you have a compound that is made up of:
You can think of these percentages as grams for a 100-gram sample.
Next, you need to turn the grams into moles. You do this by dividing by the weight of each element (called molar mass):
After you have the moles, you find the simplest ratio. This means you divide each number of moles by the smallest one among them.
Doing this will give you the numbers (called subscripts) that you will use in the empirical formula.
Finally, if any of these numbers aren't whole numbers, you just adjust them to get whole numbers.
Once you get the hang of it, this process is pretty simple!
To figure out empirical formulas using mass percentages, you start by changing those percentages into grams.
Let's say you have a compound that is made up of:
You can think of these percentages as grams for a 100-gram sample.
Next, you need to turn the grams into moles. You do this by dividing by the weight of each element (called molar mass):
After you have the moles, you find the simplest ratio. This means you divide each number of moles by the smallest one among them.
Doing this will give you the numbers (called subscripts) that you will use in the empirical formula.
Finally, if any of these numbers aren't whole numbers, you just adjust them to get whole numbers.
Once you get the hang of it, this process is pretty simple!