What is the mass and number of moles of #2.408*10^21# molecules of ammonia?

1 Answer
Sep 15, 2016

Answer:

#6.022xx10^23# ammonia molecules have a mass of #17.03*g#. And so.........

Explanation:

#(2.408xx10^21)/(6.022xx10^23*mol^-1)xx17.03*g*mol^-1# #~=# #7.0xx10^-2*g# of ammonia.

As you are no doubt aware, the number #6.022xx10^23# is #"Avogadro's number, "N_A#, which is the link between the micro world of atoms and molecules to the macro world of grams and kilograms. #N_A# ammonia molecules have a mass of #17.03*g#.

To belabour the point, #"Avogadro's number, "N_A# ammonia molecules, which is equivalent to #3xxN_A# hydrogen atoms, and #1xxN_A# nitrogen atoms, has a mass of #17.03*g#. Capisce?