# How many molecules are in 2.00 moles of NO_2?

Dec 29, 2016

$1.20 \times {10}^{24} \text{molecules}$ of $N {O}_{2}$

#### Explanation:

We are going to use dimensional analysis (method that allows you to convert from one unit of measurement to another by cancelling out unwanted units) and the relationship below:

For questions like this I use the following technique:

$\text{Quantity Given" xx "Conversion Factor" = "Quantity Sought}$

color(indigo)("Quantity Given:" 2.00 moles

color(coral)("Conversion Factor:" $6.02 \times {10}^{23}$

color(orange)("Quantity Sought:" molecules

Let's plug in our values:

2.00cancel"mol"xx(6.02xx10^23"molecules")/(1cancel"mol") = $1.20 \times {10}^{24} \text{molecules}$