About the Empirical Formula
How to find the Empirical Formula
Rounding
Practicing Finding the Formula
100

The empirical formula is the _________ ratios of the atoms in a compound 

What is lowest whole-number ratios?

100

What is your first step in creating the empirical formula if you start with the percent of each element?

You change the percent into grams

100

If you have a number that ends in 0.9 or 0.1 what do you do?

You round to the closest whole number

100

7.00g of carbon and 1.75 of hydrogen

CH3

200

What is the second step in creating the empirical formula?

You convert the grams to moles by dividing

200

If the number ends with a number higher than 0.1 or lower than 0.9, what do you do?

You have to multiply the number until you can get a whole number

200

0.175g or hydrogen, 2.44g of nitrogen, and 8.38g of oxygen

HNO3

300

What is the third step in creating the empirical formula?

You divide the mole answers by the smallest mole value

300

70.9% potassium and 29.1% sulfur

K2S

400

What is the fourth step in creating the empirical formula if the numbers are not whole numbers?

You multiply the numbers until they create whole numbers.

400

55.0% of Ga and 45.0% F

GaF3

500

What is the fifth and final step to creating the empirical formula?

You use the whole numbers you found and write out the formula using the numbers as subscripts. 

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