What is the molecular formula of ibuprofen, and what are the relative percentages of carbon, hydrogen, nitrogen, and oxygen in it?
To determine the molecular formula of ibuprofen and the relative percentages of carbon, hydrogen, nitrogen, and oxygen, we need to look up the chemical structure of ibuprofen.
Step 1: Search for the chemical structure of ibuprofen online. One reliable source is the PubChem database.
Step 2: Access the PubChem website (pubchem.ncbi.nlm.nih.gov) and search for "ibuprofen." This will take you to the ibuprofen compound page.
Step 3: On the ibuprofen compound page, you will find various information about ibuprofen, including its molecular formula and chemical structure. The molecular formula of ibuprofen is C₁₃H₁₈O₂.
Step 4: Calculate the relative percentages of each element in the molecular formula. Start by determining the molar mass of the molecule.
Carbon (C): The molecular weight of carbon is approximately 12.01 g/mol. In the molecular formula of ibuprofen (C₁₃H₁₈O₂), there are 13 carbon atoms. So, the total mass of carbon in ibuprofen is 13 * 12.01 = 156.13 g/mol.
Hydrogen (H): The molecular weight of hydrogen is approximately 1.01 g/mol. In the molecular formula of ibuprofen (C₁₃H₁₈O₂), there are 18 hydrogen atoms. So, the total mass of hydrogen in ibuprofen is 18 * 1.01 = 18.18 g/mol.
Oxygen (O): The molecular weight of oxygen is approximately 16.00 g/mol. In the molecular formula of ibuprofen (C₁₃H₁₈O₂), there are 2 oxygen atoms. So, the total mass of oxygen in ibuprofen is 2 * 16.00 = 32.00 g/mol.
Nitrogen (N): There is no nitrogen (N) present in the molecular formula of ibuprofen.
Step 5: Calculate the relative percentage of each element in the molecule by dividing the mass contribution of the element by the total molar mass of the molecule and multiplying by 100.
Carbon (C): (156.13 g/mol / (156.13 g/mol + 18.18 g/mol + 32.00 g/mol)) * 100 ≈ 71.43%
Hydrogen (H): (18.18 g/mol / (156.13 g/mol + 18.18 g/mol + 32.00 g/mol)) * 100 ≈ 8.33%
Oxygen (O): (32.00 g/mol / (156.13 g/mol + 18.18 g/mol + 32.00 g/mol)) * 100 ≈ 14.29%
Nitrogen (N): Ibuprofen does not contain nitrogen.
Therefore, the relative percentages of carbon, hydrogen, nitrogen, and oxygen in ibuprofen are approximately 71.43%, 8.33%, 0%, and 14.29%, respectively.