What is the mass of #4.50 * 10^22# atoms of gold, #Au#?

1 Answer
May 4, 2016

Answer:

#(4.50xx10^22" gold atoms")/(6.022xx10^23" gold atoms per mole")xx196.97*g*mol^-1# #=# #??# #g#

Explanation:

One mole of gold has a mass of #196.97*g*mol^-1#. By definition there are #"Avogadro's number"# of gold atoms that constitute this mass, i.e. #N_A=6.022xx10^23#.

So we take the quotient to get an answer in moles, and mulitply this by the molar mass to get the mass:

#(4.50xx10^22" gold atoms")/(6.022xx10^23" gold atoms per mole")xx196.97*g*mol^-1# #=# #??# #g#