Mole Conversions

Mole Conversions:
(Converting between Grams and Moles)


* To convert between moles & mass we use molar mass as the conversion factor
* Be sure to cancel the appropriate units!
* Use the chart below to help you with your conversions

Density
* (D = m / v)
(Molar Mass) (Molar Volume)
Mass ------ Moles ------ STP
*
(Avogadro’s #)

Molecules
*
(Subscripts)
*


Atoms

Ex. How many grams are there in 3.0 mol of O2?
* O2 = 2 x 16.0 ~ 36g / mol
* 3.0 mol x 32g / 1mol = 96.0g


Ex. Determine the # of moles of C5H12 that are in 362.8g of the compound.
* 5(12.0) + 12(1.0) = 72g / mol
* 362.8g x 1mol / 72g = 5.039mol


Ex. How many moles of magnesium bromide contain 5.38 x 10^24 formula units?
* 5.38 x 10^24molec x 1mol / 6.02 x 10^23molec = 8.39mol


Ex. Find the mass of 0.89mol of CaCl2.
* 40.1 + 2(35.5) = 111.1g / mol
* 0.89mol x 111.1g / 1mol = 99g


Ex. Find the mass of 0.159mol of SiO2.
* 28.1 + 2(16.0) = 60.1g / mol
* 0.159mol x 60.1g / 1mol = 9.56g