# What is the molar mass of calcium?

Mar 19, 2018

$40 \setminus \text{g/mol}$.

#### Explanation:

On the periodic table, it shows us that calcium has a mass of around $40 \setminus \text{amu}$.

We now need to convert from $\text{amu}$ to $\text{g/mol}$.

We know that the mass of one mole of carbon-12 atoms is $12 \setminus \text{g}$, or,

$1 \setminus \text{mol"*m_(""^12C)=12 \ "g}$, because of the definition of the mole.

And so, we get, m_(""^12C)=12 \ "g/mol".

Meanwhile, one carbon-12 atom has a mass of exactly $12 \setminus \text{amu}$, i.e. m_(""12^C)=12 \ "amu".

So, we have found out that

$12 \setminus \text{g/mol"=12 \ "amu}$

or

$1 \setminus \text{g/mol"=1 \ "amu}$

Now, a calcium atom has a mass of $40 \setminus \text{amu}$.

So, the molar mass of calcium would be $40 \setminus \text{g/mol}$.