The catch is that the audio CD is uncompressed. While you might have been able to put seven or eight hours of MP3s onto a single data CD before, youâre out of luck with an audio CD. These contain only about 70 minutes or so. It may take several audio CDs to hold what you might currently have on a single data CD.
Example 1: mass percent = (mass of chemical/total mass of compound) x 100 = (5 g/105 g) x 100. Example 2: We want to rearrange the mass percent equation to solve for the unknown mass of the chemical: mass of the chemical = (mass percent*total mass of the compound)/100 = (15*175)/100. 5. Calculate the mass percent.
5. Calculate molecular mass. The molecular mass of a substance is calculated as the number of atoms of each element multiplied by the atomic weight of that element. Knowing the molecular mass is necessary to convert grams to moles. 1  Multiply the number of atoms each element contributes to the compound by the atomic weight of that element.