Question

part 3 of 3
find the mass of 23 molecules so₂.
answer in units of g. answer in units of g.

1. 5.1013 × 10⁻²¹
2. 3.93225 × 10⁻²¹
3. 4.35736 × 10⁻²¹
4. 1.48788 × 10⁻²¹
5. 3.71969 × 10⁻²¹
6. 4.99502 × 10⁻²¹
7. 3.40086 × 10⁻²¹
8. 2.44437 × 10⁻²¹
9. 1.91299 × 10⁻²¹
10. 3.61342 × 10⁻²¹

Explanation:

Step1: Calculate molar mass of $SO_2$

Sulfur (S) has molar mass ~32.07 g/mol, oxygen (O) ~16.00 g/mol. For $SO_2$, molar mass $M = 32.07 + 2\times16.00 = 64.07$ g/mol.

Step2: Use Avogadro's number to find moles

Avogadro's number $N_A = 6.022\times10^{23}$ molecules/mol. Moles $n = \frac{\text{number of molecules}}{N_A} = \frac{23}{6.022\times10^{23}}$.

Step3: Calculate mass using $m = n\times M$

Substitute $n$ and $M$: $m = \frac{23}{6.022\times10^{23}} \times 64.07$. Calculate: $\frac{23\times64.07}{6.022\times10^{23}} \approx \frac{1473.61}{6.022\times10^{23}} \approx 2.447\times10^{-21}$ g (closest to option 8: $2.44437\times10^{-21}$).

Answer:

1. $2.44437 \times 10^{-21}$