Moles to Atom/Molecules Conversion

Objectives: 

•  Know how to convert from moles to number of molecules
•  Know how to determine the number of atoms in a chemical sample

 

Example: How many atoms are there in 1.5 mol of Iron?

•  1.5 mol x (6.02 x 10²³ atoms / 1 mol) = 9.03 x 10²³ atoms

Example: How many water molecules are there in 0.65 mol?

•  0.65 mol x (6.02 x 10²³ molecules / 1 mol) = 3.9 x 10²³ molecules

Example: A cylinder of Helium contains 4.6 x 10³⁰ atoms. How many moles of

              Helium is this ?

•  4.6 x 10³⁰ atoms x (1 mol / 6.02 x 10²³ atoms) = 7.64 x 10⁶ mol

 Example: A sample of Zinc Sulphate contains 5.0 x 10²² atoms of Oxygen. How 

               many moles of Oxygen is this ?

•  5.0 x 10²² atoms x (1 mol / 6.02 x 10²³ atoms ) = 0.083 mol

Example: A glass contains 5.0 mol of Vinegar (CH3COOH). How many molecules 

              are there in the glass?

•  5.0 mol x (6.02 x 10²³ molecules / 1 mol) = 30.1 x 10²³ molecules

-Eva