Aspirin is a compound that contains carbon, hydrogen, and oxygen. It is used as a painkiller. An aspirin tablet contains 25 x 1030 molecules. How many moles of this compound are present in the tablet?
Difficulty: Hard
Solution:
Number of molecules = 1.25 x 1030 molecules
Avogadro's number = NA = 6.022 x 1023
Number of moles = ?
Number of moles = $\frac{\text{Number of molecules}}{N_{A}}$
Number of moles = $\frac{1.25\times10^{30}}{6.022\times10^{23}}$
Number of moles = 0.2076 x 1030-23
Number of moles = 0.2076 x 107
Number of moles = 2.076 x 106 moles