Benzoyl peroxide (C14H10O4) is a substance used as an acne medicine. What is the mass in grams of 3.50 x 10-2 mole of benzoyl peroxide?

Answer 1

Hello, John,

We need the molar mass of C₁₄H₁₀O₄. I'll assume you know how this is calculated. Let me know if you have a question. I find the molar mass to be 242 g/mole. It takes 242 grams to provide 6.023x10²³ molecules of the molecule.

We want the number of grams in 3.50x10^-2 moles. Look at the units - we have the conversion factor, molar mass, in g/mole. We have moles, but want grams.

(3.50x10^-2 moles.)*(242 g/mole) = 8.47grams

I always watch for the units to help guide me through these calculations.

Bob