Mole Calculations (Page 2 of 4) in pdf

Mole Calculations Page 2

Step 5: Create a relationship between the starting point and the

first stop. For some problems, the first stop will be the final

destination.

In this case your first stop is at moles; therefore, you want to create a relationship

between grams of Oxygen and moles of Oxygen. Whenever you create a relationship

between grams and moles, it is necessary to use your periodic table to determine the molar

mass. If this were a molecule (i.e. – H

O) it would be necessary for you to use your

periodic table to calculate its molar mass.

37 grams of Oxygen x

mole of Oxygen

16 grams of Oxygen

Step 6: Create a relationship between the first stop and the

final destination.

In this case it is necessary to create a relationship between moles of Oxygen and

atoms of Oxygen. Whenever you create a relationship between moles and atoms

(molecules, particles, etc.) it is necessary to use 1 mole = 6.02 X 10

37 grams of Oxygen x 1 mole of Oxygen x 6.02x10²³ atoms of Oxygen

16 grams of Oxygen

1 mole of Oxygen

Step 7: Cancel all possible units. This should leave only the units

that represent the final destination.

37 grams of Oxygen x 1 mole of Oxygen x 6.02x10

atoms of Oxygen

16 grams of Oxygen

1 mole of Oxygen

Step 8: Multiply all numbers on the top. Multiply all numbers on

the bottom. Divide the product of the top by the product of the

bottom.

(37))(1)(6.02x10

atoms of Oxygen) = 2.23x10

atoms of Oxygen = 1.39x10

atoms of Oxygen

(1)(16)(1)

Mole Calculations Page 2