Answer: There are 0.000043 moles of melatonin.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
given mass = 10 mg = 0.01 g
molar mass of [tex]C_{13}H_{16}N_2O_2[/tex] = 232.28 g
[tex]{\text {moles of melatonin}}=\frac{0.01g}{232.28g/mol}=0.000043moles[/tex]
Thus there are 0.000043 moles of melatonin
