Question

How many moles of ethanol, C2H5OH, are in a sample which weighs 39.2 g? (Hint: your answer needs to be less than the 1 mole b/c you're asked about the mole equivalent of 39.2g, which is less than 1 mole of ethanol)

Answer 1

Answer:

Explanation:

To find how many moles are in the sample, you first must calculate how much one mole of C2H5OH weighs.

2(mass of C) + 5(mass of H) + (mass of O) + (mass of H)

= 2(12.01) + 5(1.008) + (16.00) + (1.008) = 46.068 g/mol

So, now that we know what 1 mole weighs, we can simply divide the weight of the sample by the weight of a mole of ethanol to get our answer.

39.2 / 46.068 = approximately 0.851 mol of ethanol