How many formula units are present in 3.6 grams of NaCl?

• A. 3.7 × 10^{22}
• B. 1.2 × 10^{21}
• C. 6.0 × 10^{23}
• D. 2.1 × 10^{24}

Answer: (A)

Verified step by step guidance

1. Determine the molar mass of NaCl by adding the atomic masses of sodium (Na) and chlorine (Cl). Use the periodic table values: approximately 22.99 g/mol for Na and 35.45 g/mol for Cl. So, calculate the molar mass as \(\text{Molar mass of NaCl} = 22.99 + 35.45\) g/mol.
2. Calculate the number of moles of NaCl in 3.6 grams using the formula \(n = \frac{\text{mass}}{\text{molar mass}}\). Substitute the given mass and the molar mass you found in step 1: \(n = \frac{3.6}{\text{molar mass of NaCl}}\) moles.
3. Recall that one mole of any substance contains Avogadro's number of formula units, which is \$6.022 \times 10^{23}$ formula units/mole.
4. Calculate the total number of formula units by multiplying the number of moles by Avogadro's number: \(\text{formula units} = n \times 6.022 \times 10^{23}\).
5. Express your answer in scientific notation to match the format of the options provided.