How many moles of CuSO_4 · 5H_2O are present in a 3.10 g sample?

• A. 0.0620 mol
• B. 0.0124 mol
• C. 0.155 mol
• D. 0.0194 mol

Answer: (B)

Verified step by step guidance

1. Identify the compound given: copper(II) sulfate pentahydrate, CuSO_4 \cdot 5H_2O.
2. Calculate the molar mass of CuSO_4 \cdot 5H_2O by summing the atomic masses of all atoms in the formula: Cu, S, 4 O, and 5 H_2O molecules.
3. Use the formula for moles: \(\text{moles} = \frac{\text{mass of sample (g)}}{\text{molar mass (g/mol)}}\).
4. Substitute the given mass (3.10 g) and the calculated molar mass into the formula to find the number of moles.
5. Perform the division to find the moles of CuSO_4 \cdot 5H_2O in the sample.