# What is the molar mass of lithium oxide, #Li_2O#?

##### 2 Answers

#### Explanation:

**atomic weight of element #xx#number of atoms given by subscript #=# molar mass**

First, you want to have your handy dandy periodic table available so you can determine the atomic weight of Li and O:

Li has an atomic weight of 6.94 g/mol

O has an atomic wight of 16.00 g/mol

Based on the chemical formula, we have 2 atoms of Li, so the atomic weight of Li has to be multiplied by 2 to obtain 13.88 g/mol.

You have 1 atom of O, so the atomic mass would just be 16.00 g/mol

Now you want to add the mass of each atom together to obtain the molar mass of the entire compound:

If you refer to your periodic table, the atomic weight is the molar mass of each element.

The molar mass of Lithium is 6.9 g/mol and Oxygen 16.0 g/mol.

Since there are 2 atoms of Lithium - if you look closely in

the molar mass of lithium

Add the molar masses of Lithium and Oxygen together:

13.8 g/mol + 16.0 g/mol therefore the molar mass of Lithium oxide is 29.8 g/mol.