A typical cup of coffee has about 100. mg of caffeine. Calculate the number of caffeine molecules in 100. mg C₈H₁₀N₄O₂.

Question

Quizplus · Accepted Answer

To find the number of caffeine molecules, first calculate the moles of caffeine: 100 mg = 0.1 g. The molar mass of caffeine (C₈H₁₀N₄O₂) is approximately 194.19 g/mol. Moles = 0.1 g / 194.19 g/mol ≈ 0.000515 moles. Using Avogadro's number (6.022 × 10²³ molecules/mol), the number of molecules = 0.000515 moles × 6.022 × 10²³ molecules/mol ≈ 3.10 × 10²⁰ molecules.

A Typical Cup of Coffee Has About 100