# What is the number of grams in 7.19 moles of BaSO_4?

Apr 25, 2016

7.19 moles $\times$ molar mass of $B a S {O}_{4}$

#### Explanation:

Assume:
n = number of moles
m = mass of substance
M = molar mass

7.19 moles has been provided for you

Your next step is to find the molar mass (M) of $B a S {O}_{4}$.
Unsure what is molar mass? Molar mass is equivalent to the atomic weight on the periodic table.

Your first step in finding molar mass is to find out what elements are present in $B a S {O}_{4}$. As you can see: Barium, Sulfur and Oxygen are present.

If you refer to your periodic table, the molar mass of Barium is 137 g/mol, Sulfur 32.1 g/mol, and Oxygen 16.0 g/mol.

Since there are 4 oxygens present, you need to times the molar mass of oxygen (O) by 4.

Therefore the molar mass of $B a S {O}_{4}$ is
[$1 \times 137 + 1 \times 32.1 + 4 \times 16.0$] = 233.1 g/mol

You've now found the molar mass.

Since you found the number of moles and molar mass, your final step is to find the mass of $B a S {O}_{4}$.

The mass of $B a S {O}_{4}$ is:
$m = M \times n$
[233.1 g/mol $\times$ 7.19 moles] = 1676 grams. This final answer is rounded to nearest whole number.