Question

Theobromine, C7H8N4O2, is a component of chocolate. It is mildly diuretic, is a mild stimulant, and relaxes the smooth muscles of the bronchi in the lungs. Because dogs metabolize it more slowly than humans, theobromine is very toxic to dogs.
If there are 0.064 g of theobromine in a 43 g chocolate bar, how many moles of theobromine are there?
a) 1.5 x 10−3 moles
b) 3.55181 x 10−4 moles
c) 3.6 x 10−4 moles
d) 12 moles

Answer 1

Answer:

$3.6\times 10^{-4}$ moles of Threobromine are present in chocolate bar

Explanation:

Molar mass of Theobromine = ($7\times$molar mass of C)+($8\times$molar mass of H)+($4\times$molar mass of N)+($2\times$molar mass of O) = ($7\times$12g/mol)+($8\times$1g/mol)+($4\times$14g/mol)+($2\times$16g/mol) = 180 g/mol

We know that, number of moles of a compound is the ratio of mass to molar mass of the compound.

So, 0.064 g of Threobromine = $\frac{0.064}{180}$ moles of Threobromine = $3.6\times 10^{-4}$ moles of Threobromine