question 21\n1 point\nyour average cup coffee contains 1.15e2 mg of caffeine, how many moles of caffeine are…

question 21\n1 point\nyour average cup coffee contains 1.15e2 mg of caffeine, how many moles of caffeine are in the cup of coffee? given caffeine is c8h10n4o2 and has a molar mass of 194.0 g/mol.\na 5.93e-1 moles\nb 2.23e1 moles\nc 5.93e-4 moles\nd 2.23e4 moles\ne none of the above

question 21\n1 point\nyour average cup coffee contains 1.15e2 mg of caffeine, how many moles of caffeine are in the cup of coffee? given caffeine is c8h10n4o2 and has a molar mass of 194.0 g/mol.\na 5.93e-1 moles\nb 2.23e1 moles\nc 5.93e-4 moles\nd 2.23e4 moles\ne none of the above

Answer

Explanation:

Step1: Convert mass to grams

$1.15\text{E}2\ mg = 115\ mg=115\times10^{- 3}\ g = 0.115\ g$

Step2: Use mole - mass formula

The formula for calculating the number of moles $n$ is $n=\frac{m}{M}$, where $m$ is the mass and $M$ is the molar mass. Given $m = 0.115\ g$ and $M=194.0\ g/mol$, then $n=\frac{0.115\ g}{194.0\ g/mol}\approx5.93\times10^{-4}\ mol$

Answer:

C. 5.93E-4 moles