# What is the total number of atoms contained in 2.00 moles of nickel?

May 25, 2017

$2 \times {N}_{A}$, where ${N}_{A} = \text{the avocado number........}$

#### Explanation:

${N}_{A} = \text{Avogadro's number}$, where ${N}_{A} = 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$. This is simply a number like 10, or 12, or 100, or 1000. The reason we use ${N}_{A}$ is that ${N}_{A}$ ""^1H atoms has a mass of $1 \cdot g$ precisely. ${N}_{A}$ is thus the numerical link between the sub-micro world of atoms and molecules to the macro world of grams and kilograms.

With our Periodic Table (beside you if you are doing your chemistry homework!) we find that the molar mass (i.e. the mass of ${N}_{A}$ nickel atoms) is $58.7 \cdot g \cdot m o {l}^{-} 1$.

And so to find the mass, we calculate the product:

$\text{Mass} = 2 \cdot m o l \times 58.7 \cdot g \cdot m o {l}^{-} 1 = 117.4 \cdot g$...........