# Which of the following has the largest number of oxygen atoms?

## a) $3.65 \times {10}^{20}$ molecules of ${\text{SO}}_{2}$ b) $3.65 \times {10}^{20}$ molecules of ${\text{SO}}_{3}$ c) ${\text{0.0553 g SO}}_{3}$ d) $5.06 \times {10}^{- 3} {\text{mols SO}}_{3}$

Jul 6, 2017

The biggest amount of oxygen is in $\text{5,06" × 10^"-3}$ mol.

#### Explanation:

Since a mol is $6 , 02 \times {10}^{23}$ molecules, you have $\frac{3 , 65 \times {10}^{20}}{6 , 02 \times {10}^{23}} = 6 , 06 \times {10}^{- 4}$ mol each of $S {O}_{2}$ and $S {O}_{3}$.

Obviously, there are more oxygen atoms in $S {O}_{3}$.

Furthermore, since the MM of $S {O}_{3}$ is 80.1 g/mol you have $\frac{0 , 0553 g}{80.1 \frac{g}{m o l}} = 6 , 90 \times {10}^{- 4} m o l S {O}_{3}$.

Then, the bigger amount of oxygen is in the 0,0553 g of $S {O}_{3}$ where there is a bigger number of moles.

And $\text{5,06" × 10^"-3}$ mol of $S {O}_{3}$ contains even more moles than 0,0553 g of $S {O}_{3}$.