## Chemistry Tutorial

#### Intro

Avogadro’s number (6.02×10^23) is defined as the number of molecules, atoms, compounds, etc. per mole of a substance. Elementary particles like atoms and molecules are tiny. It is much easier to say there is 1 mole of a substance than 602,000,000,000,000,000,000,000 atoms in a certain substance.
The molar mass of a substance is the number of grams in a single mole. These numbers can be found on the periodic table and are expressed in g/mol.
In this problem, we are going to convert from moles to grams.

#### Sample Problem

How many grams are in 5 moles of table salt (NaCl)?

#### Solution

To convert from moles to grams, first we need to find the molar mass of NaCl.
From the periodic table, we can find that the molecular mass of sodium is 22.99 g/mol and the molecular mass of chlorine is 35.45 g/mol. By adding these two numbers together, we determine the molecular mass of sodium chloride, 55.84 g/mol.

After we have the molecular mass, we can set up or equation. The formula for moles to grams is We plug 5 moles and 55.84 into their respective places in the equation. And then we simply just multiply across! 