The molecular formula of aspirin is C₉H₈O₄.How many aspirin molecules are present in one 500-milligram tablet?

Question

Quizplus · Accepted Answer

The molecular weight of aspirin (C9H8O4) is (9 x 12.01 + 8 x 1.01 + 4 x 16.00) g/mol = 180.16 g/mol. 
Therefore, in one 500 mg tablet (0.5 g), the number of molecules present can be calculated as:
(0.5 g / 180.16 g/mol) x Avogadro's number = 1.67 × 10²¹ molecules ≈ 1.67 × 10²¹. 
Thus, the best answer is D.

The Molecular Formula of Aspirin Is C9H8O4

The Molecular Formula of Aspirin Is C₉H₈O₄