What is the molecular weight of ibuprofen, C13H18O2? Note: Chemists like to distinguish between whether the polyatomic structure is held together exclusively by covalent bonds or a mix of covalent and ionic bonds. For the example of ibuprofen, all the bonds holding the polyatomic complex together are covalent. So, Chemists use the name "molecular weight" instead of "formula weight". Both words have the same meaning, otherwise.
a) 29.0 amu
b) 206.3 amu
c) 289.4 amu
d) 377.7 amu
To find the molecular weight of ibuprofen, we need to calculate the sum of the atomic weights of all the atoms in the molecule.
The atomic weight of carbon (C) is 12.01 amu, the atomic weight of hydrogen (H) is 1.01 amu, and the atomic weight of oxygen (O) is 16.00 amu.
Let's calculate:
(13 atoms of C x 12.01 amu) + (18 atoms of H x 1.01 amu) + (2 atoms of O x 16.00 amu) = 156.13 amu + 18.18 amu + 32.00 amu = 206.31 amu
Therefore, the molecular weight of ibuprofen is approximately 206.3 amu.
The correct answer is b) 206.3 amu.