Molar Mass

What is Molar Mass? 

Molar mass is the mass (in grams) of 1 mole of a substance. 

How do you find Molar Mass? 

This number can be determined from the atomic mass given on the periodic table as shown below:

 

As you can see, there a0re four significant digits given in the atomic mass and in some instances even more. For our application and purposes, we will only use one digit past the decimal point for the atomic mass. Molar mass is expressed as g/mol, therefore the element above can be said to have a molar mass of 58.93 g/mol.  

• Hydrogen = 1.0 g/mol  
• Zinc = 65.4 g/mol 

How do you find Molar Mass of Compounds? 

To determine the molar mass of compounds, simply add the mass of all the atoms together: 

• Water (H2O) = 2(1.0) + 16.0 = 18.0 g/mol  
• Aluminum Chloride (AlCl3) = 27.0 + 3(35.0) = 133.5 g/mol  

The following video should clarify any confusions. Underneath that thick southern accent are some fine examples:

-Simon Sierra