# What is the mass of 0.1*mol of sodium metal?

May 25, 2017

Well, the mass of one mole of sodium is $22.99 \cdot g$........

#### Explanation:

How do I know this? Well, I have got a Periodic Table beside me, and you should have one beside you too.

And so we take the product............

$0.1 \cdot \cancel{m o l} \times 22.99 \cdot g \cdot \cancel{m o {l}^{-} 1} = 2.30 \cdot g \ldots \ldots \ldots .$

This is an example or what is called dimensional analysis. We wanted an answer in $\text{grams}$, and the product gave us an answer with dimensions of $\text{grams}$. This persuades us that we got the order of operations right. It is all too easy to divide when you should multiply, or vice versa.