# What is the molar mass of lactic acid, #C_3H_6O_3#?

##### 1 Answer

90.08 g/mol

#### Explanation:

Before we begin here's a tip:

**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 C, H, O

C has an atomic weight of 12.01 g/mol

H has an atomic weight of 1.008 g/mol

O has an atomic wight of 16.00 g/mol

Based on the chemical formula, we have 3 atoms of carbon so you would multiply the atomic weight of C by 3 to obtain 36.03 g/mol.

You do the same for hydrogen, we have 6 atoms of H so you multiply the atomic weight of H by 6 to get 6.048 g/mol

Lastly, for O you would multiply 16.00g/mol by 3 to obtain 48.00 g/mol

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

**48.00 g/mol + 6.048 g/mol + 36.03 g/mol** = **90.08 g/mol**