If you have 644 grams of retinol (C20H30O), how many moles of retinol do you have?

• A. 3.00 moles
• B. 0.75 moles
• C. 2.25 moles
• D. 1.50 moles

Answer: (C)

Verified step by step guidance

1. Identify the molecular formula of retinol, which is C20H30O, and use it to calculate its molar mass by summing the atomic masses of all atoms in the formula.
2. Calculate the molar mass using the atomic masses: Carbon (C) = 12.01 g/mol, Hydrogen (H) = 1.008 g/mol, and Oxygen (O) = 16.00 g/mol. Use the formula: \(\text{Molar mass} = (20 \times 12.01) + (30 \times 1.008) + (1 \times 16.00)\).
3. Once the molar mass is found, use the given mass of retinol (644 grams) to find the number of moles by applying the formula: \(\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\).
4. Substitute the values into the formula: \(\text{moles} = \frac{644}{\text{molar mass}}\) to calculate the number of moles of retinol.
5. Interpret the result to determine which of the provided answer choices (3.00, 0.75, 2.25, or 1.50 moles) matches the calculated number of moles.