How do you find the moles of a compound when no mass is given?

Answer 1

You have to use the molar mass of the element to convert the total amount of grams in the compound to the amount of grams in the element in the compound. After that use the mole ratio by using the amount of molecules in the reactant and divide it by the amount of molecules (moles in this case) to find the amount of mole... You should use the factor label method so that it's easier to plug into your calculator, just multiply or divide straight through. If you wrote it Out correctly all of your units except for moles should have cancelled out along the way...go chem!

Answer 2

Thanks to some jokester I have to do this answer all over again. I hate that about this site. Anyone can but in!

Perhaps you will be given atoms of the compound.

3.42 X 10^22 atoms carbon (1 mole C/6.022 X 10^23)

= 0.057 moles Carbon

-----------------------------or, you will be given,

Molarity and Liters of solution

Molarity = moles of solute/Liters of solution

Moles of solution = Molarity * Liters of solution

-------------------------------------------------------------there are two ways without mass of element/compound

If that is not what you meant put a message on my message board.

Answer 3

Without the mass of the compound, you can't directly determine the number of moles. You would need either the mass or volume of the compound and its molar mass to calculate the number of moles using the formula moles = mass / molar mass or moles = volume / molar volume for gases at STP.