# What equivalence factor should you use to convert from 4.28 x 10^19 molecules of oxygen (O_2) to moles of O_2?

Sep 3, 2016

Divide by $\text{Avogadro's Number} , 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$

#### Explanation:

$1 \cdot \text{mole}$ of stuff specifies $\text{Avogadro's Number} , 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$, i.e. ${N}_{A}$ individual items of stuff.

If I have $4.28 \times {10}^{19}$ dioxygen molecules, I have a molar quantity of $\frac{4.28 \times {10}^{19}}{6.022 \times {10}^{23} \cdot m o {l}^{-} 1}$ $=$ ?? moles of ${O}_{2}$?

Since I know (how?) that $1$ $\text{mole } {O}_{2}$ has a mass of $32.00 \cdot g$, what is the mass of your quantity?