How many molecules are present in 3.6 grams of NaCl?

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

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. The molar mass of NaCl is calculated 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 \(n = \frac{\text{mass}}{\text{molar mass}}\), where \(n\) is the number of moles, the mass is 3.6 g, and the molar mass is from step 1.
3. Use Avogadro's number, which is \$6.022 \times 10^{23}\( molecules per mole, to convert moles of NaCl to molecules. The formula is \)\text{Number of molecules} = n \times 6.022 \times 10^{23}$.
4. Substitute the value of \(n\) from step 2 into the equation from step 3 to find the total number of NaCl molecules in 3.6 grams.
5. Express the final answer in scientific notation to match the format of the given options.