What mass of #"calcium carbonate"# is equivalent to #"Avogadro's number"# pf formula units of #CaCO_3#?

1 Answer
Apr 23, 2017

A mass of #100.09*g# is specified.

Explanation:

#6.022xx10^23# units of ANYTHING, specifies 1 mole of that thing, i.e. #N_A# individual units of that thing...........

And thus in #1*mol# of #CaCO_3#, #N_A# formula units, there are: #N_A# #Ca# atoms; #N_A# #C# atoms; and #3xxN_A# #O# atoms.

Because #N_A# #""^12C# atoms have a mass of #12.00*g#, and #N_A# #""^40Ca# atoms have a mass of #40.00*g#, and #N_A# #""^16O# atoms have a mass of #16.0*g#, if we sum the masses appropriately we get a mass of approx. #100*g#, per molar quantity. Agreed?

From where did I get these molar masses? From where will YOU get the atomic mass if asked this question is asked of you in a test?