1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chemistry mol and grams

  1. Sep 3, 2009 #1
    1. The problem statement, all variables and given/known data
    How many grams are there in 6.80 moles of potassium sulfide? How many moles are there in 200g of barium nitride?

    2. Relevant equations

    I just want to see if i got the right answer

    3. The attempt at a solution
    for part A. i got 759g by multiplying 6.80x110.24(molar mass of K2S)

    part B. 0.455 mol by dividing 200?439.99(molar mass of Ba3N2)
  2. jcsd
  3. Sep 4, 2009 #2


    User Avatar

    Staff: Mentor

    6.80*110.24 is not 759 :wink:

    But that's probably a typo.

  4. Sep 6, 2009 #3
    From "Thermodynamics An Engineering Approach" by Cengel and Boles, "Molar mass can be defined as the mass of one mole of a substance in grams, or the mas of one kmol (kilogram-mole) in kilograms." then they go on to say "The mass of a system is equal to the product of it's molar mass M and mole number N."

    You should be able to get it on your own now.

    Last edited: Sep 6, 2009
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook