Calculate the percentage by mass of oxygen in the following compounds: (a) vanillin, C8H8O3

Key Concepts

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all the atoms in a chemical formula. For example, in vanillin (C8H8O3), the molar mass is determined by adding the contributions from carbon, hydrogen, and oxygen atoms based on their respective quantities.

Percentage by Mass

Percentage by mass is a way to express the concentration of a particular element in a compound. It is calculated by dividing the mass of the element by the total mass of the compound and then multiplying by 100. This calculation helps in understanding the composition of compounds and is essential for stoichiometric calculations in chemistry.

Chemical Formula Interpretation

Interpreting a chemical formula involves understanding the types and numbers of atoms present in a compound. In the case of vanillin (C8H8O3), the formula indicates there are 8 carbon atoms, 8 hydrogen atoms, and 3 oxygen atoms. This information is crucial for calculating the molar mass and subsequently the percentage by mass of each element in the compound.