# How many atoms are in a mole of barium chloride, BaCl_2?

Feb 11, 2016

Clearly there are $3$ $\text{moles}$ of atoms in one mole of $B a C {l}_{2}$.

#### Explanation:

If I asked how many atoms there were in a dozen formula units of $B a C {l}_{2}$, I think you would quickly answer 3 dozen: 12 barium atoms, and 24 chlorine atoms.

The question specified molar quantities, and the mole is just another number, admittedly a very large number, i.e. ${N}_{A}$ $=$ $6.022 \times {10}^{23}$ $m o {l}^{-} 1$.

So in $1$ mole of $B a C {l}_{2}$, there are $3$ $\times$ ${N}_{A}$ barium and chlorine atoms, where ${N}_{A}$ is Avogadro's number, $6.022 \times {10}^{23}$.

What is the actual mass of this quantity of barium chloride?