(a) Ibuprofen is a common over-the-counter analgesic with the formula C₁₃H₁₈O₂. How many moles of C₁₃H₁₈O₂ are in a 500-mg tablet of ibuprofen? Assume the tablet is composed entirely of ibuprofen.

Verified step by step guidance

1. First, determine the molar mass of ibuprofen (C13H18O2) by adding the atomic masses of all the atoms in the formula. Use the periodic table to find the atomic masses: Carbon (C) is approximately 12.01 g/mol, Hydrogen (H) is approximately 1.01 g/mol, and Oxygen (O) is approximately 16.00 g/mol.
2. Calculate the molar mass of ibuprofen by multiplying the number of each type of atom by its atomic mass and then summing these values: (13 * 12.01 g/mol) + (18 * 1.01 g/mol) + (2 * 16.00 g/mol).
3. Convert the mass of the ibuprofen tablet from milligrams to grams, since molar mass is in grams per mole. Remember that 1 gram = 1000 milligrams, so divide 500 mg by 1000 to convert to grams.
4. Use the formula for moles, which is: moles = mass (in grams) / molar mass (in g/mol). Substitute the mass of the ibuprofen tablet in grams and the molar mass of ibuprofen into this formula.
5. Perform the division to find the number of moles of ibuprofen in the 500-mg tablet. This will give you the final answer in moles.