Given 60.0 grams of NaOH and 2.73 grams of NH4Cl, which of the following correctly represents the number of moles of each substance?

• A. NaOH: 2.00 mol, NH4Cl: 0.0730 mol
• B. NaOH: 0.500 mol, NH4Cl: 0.100 mol
• C. NaOH: 1.20 mol, NH4Cl: 0.0300 mol
• D. NaOH: 1.50 mol, NH4Cl: 0.0512 mol

Answer: (D)

Verified step by step guidance

1. Identify the molar masses of each compound. For NaOH, calculate the molar mass by adding the atomic masses of Na (approximately 22.99 g/mol), O (approximately 16.00 g/mol), and H (approximately 1.01 g/mol). For NH4Cl, sum the atomic masses of N (approximately 14.01 g/mol), H (4 × 1.01 g/mol), and Cl (approximately 35.45 g/mol).
2. Use the formula to calculate moles: \(\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\). Apply this formula separately for NaOH and NH4Cl using their given masses and calculated molar masses.
3. For NaOH, divide the given mass (60.0 g) by its molar mass to find the number of moles of NaOH.
4. For NH4Cl, divide the given mass (2.73 g) by its molar mass to find the number of moles of NH4Cl.
5. Compare the calculated moles of each substance to the options provided to confirm which pair matches the calculated values.