Final answer:
To find the number of ibuprofen molecules in a tablet containing 250.0 mg of ibuprofen (C13H18O2), you can convert the mass of ibuprofen to moles and then use Avogadro's number to find the number of molecules.
Step-by-step explanation:
To find the number of ibuprofen molecules in a tablet containing 250.0 mg of ibuprofen (C13H18O2), we first need to convert the mass of ibuprofen to moles. We can use the molecular mass of ibuprofen to do this calculation. The molecular mass of ibuprofen can be calculated by adding up the atomic masses of all the atoms in the formula.
The molecular mass of C13H18O2 = (13 * atomic mass of C) + (18 * atomic mass of H) + (2 * atomic mass of O).
Once we have the number of moles of ibuprofen, we can use Avogadro's number (6.022 x 10^23) to convert to the number of molecules.
Let's start by calculating the molecular mass of ibuprofen:
Molecular mass of C13H18O2 = (13 * 12.01 amu) + (18 * 1.008 amu) + (2 * 16.00 amu) = 206.28 amu (rounded to four significant figures).
Next, we can calculate the number of moles of ibuprofen in 250.0 mg using the formula:
Number of moles = mass (in grams) / molecular mass = 0.250 g / 206.28 g/mol = 0.001212 mol (rounded to four significant figures).
Finally, we can convert the number of moles to the number of ibuprofen molecules using Avogadro's number:
Number of ibuprofen molecules = number of moles x Avogadro's number = 0.001212 mol x (6.022 x 10^23 molecules/mol) = 7.303 x 10^20 molecules (rounded to four significant figures).