How many moles of pyridine (C5H5N) are contained in 3.13 g of pyridine? (Molar mass of C5H5N = 79.10 g/mol)

• A. 0.0396 mol
• B. 0.0250 mol
• C. 0.253 mol
• D. 0.396 mol

Answer: (A)

Verified step by step guidance

1. Identify the given information: mass of pyridine = 3.13 g, molar mass of pyridine (C5H5N) = 79.10 g/mol.
2. Recall the formula to calculate moles from mass and molar mass: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
3. Substitute the given values into the formula: \(\text{moles} = \frac{3.13\ \text{g}}{79.10\ \text{g/mol}}\).
4. Perform the division to find the number of moles (do not calculate the final value here, just set up the expression).
5. Interpret the result as the amount of pyridine in moles contained in the 3.13 g sample.