get the number of molecules within Benzoyl Peroxide

Question

This is what I have so far but I don't know how to get the number of molecules within Benzoyl Peroxide?

Benzoyl Peroxide aqueous Base, Acne Treatment Gel contains 10% of benzoyl peroxide (C14H10O4)

Molar mass of benzoyl peroxide is (2x14) + (1x10) + (16x4) = 168 + 10 + 64 = 242 g/mol

Answer 1

Hello, Joana,

There needs to be a value, or information, that would allow the calculation of the total mass of the Benzoyl Peroxide. We have the %, but not the amount. Once we have enough information to know the numer of grams, use the molar mass (g/mole) to find the number of moles (mass/molar mass = moles).

Then multipky the number of moles by Avogadro;s number to find the number of molecules.

Moles x 6.02x10²³ molecules/mole = molecules

Bob

Answer 2

If you assume that the BP is 10% by mass, you can work out an estimate for the mass used for an application and multiply by 10% to get the mass of BP. You can then convert to moles and then, molecules. I don't think the answer is important - just that you have a reasonable plan and know what you are doing.