An average cup of coffee contains about 125 mg of caffeine, #C_8H_10N_4O_2#. How many moles of caffeine are in a cup, and how many molecules of caffeine?

1 Answer
anor277
Nov 22, 2015

Enough caffeine to keep you up at night?

Explanation:

The molecular mass of caffeine is #194.19# #g*mol^-1#.

Moles of caffeine in a cup #=# #(125xx10^-3g)/(194.19*g*mol^-1# #=# #??# #mol#.

The above calculation gives an answer in moles. This is simply a number, i.e. #N_A*mol*xx(125xx10^-3g)/(194.19*g*mol^-1# #=# #??#

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