How many molecules are present in 13.5 g of sulfur dioxide (SO_2)?

• A. 2.84 × 10^{22} molecules
• B. 6.02 × 10^{23} molecules
• C. 1.27 × 10^{23} molecules
• D. 4.52 × 10^{24} molecules

Answer: (C)

Verified step by step guidance

1. Determine the molar mass of sulfur dioxide (SO\_2) by adding the atomic masses of sulfur (S) and oxygen (O). The atomic mass of sulfur is approximately 32.07 g/mol, and oxygen is approximately 16.00 g/mol. Since there are two oxygen atoms, calculate the molar mass as: \$32.07 + 2 \times 16.00$ g/mol.
2. Calculate the number of moles of SO\_2 in 13.5 g using the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\). Substitute the given mass (13.5 g) and the molar mass found in step 1.
3. Use Avogadro's number, which is \$6.022 \times 10^{23}\( molecules per mole, to convert moles of SO\_2 to molecules. The formula is: \)\text{number of molecules} = \text{moles} \times 6.022 \times 10^{23}$.
4. Multiply the number of moles calculated in step 2 by Avogadro's number to find the total number of SO\_2 molecules in 13.5 g.
5. Express the final answer in scientific notation to match the format of the options provided.