What id the mass in grams of 2.00 x 10^23 molecules of F2?

1 Answer
Feb 1, 2018

#"12.62g " F_2#


You have to go from molecules, to moles, to grams
Remember #"1 mole"= 6.02*10^23 " molecules"#
And then to go to grams you multiply moles by the atomic mass from the periodic table for the element, but since it's F2 you'll have to multiply that mass by 2. So:
Atomic mass of #F_2= 38g#. Use dimensional analysis using this conversion factors

#2*10^23 " molecules" * ("1 mol F2")/(6.02*10^23 "molecules") *(38g)/"1 mole F2" = "12.62g " F_2#