# If a cup of your favorite coffee contains 256 mg of caffeine, how many mL of the energy drink will provide the same amount of caffeine? ?

As you are studying for finals, you calculate the concentration of caffeine in an energy drink and discover that it is 0.04529 M in caffeine. The molecular formula of caffeine is C8H10N4O2.

### 6 Answers

- Roger the MoleLv 710 months agoFavorite Answer
(256 x 10^-3 g C8H10N4O2) / (194.1906 g C8H10N4O2/mol) / (0.04529 mol/L) =

0.0291 L = 29.1 mL

- JimLv 710 months ago
Always start with your "given" and multiply by (1) to convert:

0.256 C8H10N4O2 * (1mol/194.19 g C8H10N4O2) * (1L/0.04529 mol) =g top and bottom cancel, as does moles, leaving Liters0.0291 L = 29.1 mL

- Anonymous10 months ago
Only one way to be sure. Start drinking and keep drinking until you think you're about as hyper as you'd be from your favorite coffee drink.

- Dr WLv 710 months ago
via dimensional analysis

.. 256mg caffeine... 1 mmol caffeine..... 1 mL energy drink

---- ---- ---- ---- --- x ----- ---- ----- ----- x ----- ----- ---- ---- ------ -- = 29.1 mL energy drink

.. .. ... ... 1.... .... ... 194.2 mg caffeine... 0.04529 mmol caffeine

- How do you think about the answers? You can sign in to vote the answer.
- 10 months ago
The moles of caffeine that you need is 0.256/Mw of caffeine which is basically m/Mw.

You have the concentration which is 0.04529 and you have the number of moles that we just calculated... find the volume... which is V=n/c, that will give you the volume in litres.