CHEM 1030 Lecture Notes - Lecture 4: Unified Atomic Mass Unit, Molecular Mass, Molar Mass

• School: Auburn University
• Department: Chemistry
• Course: CHEM 1030
• Professor: Ellen Patricia Broering

Document Summary

Chem 1030- lecture 4-atoms, ions, and molecules: the building blocks of matter. Multiply the natural abundance of each isotonic element by each of there mass in amu and then adding each product mx=a1m1 + a2m2 + a3m3 + . Neon-20 with a mass of 19. 9924 amu and an abundance of 90. 4838% Neon-21 with a mass of 20. 9940 amu and an abundance of 0. 2696% Neon-22 with a mass of 21. 9914 amu and an abundance of 9. 2465% Step 1: multiply mass by abundance (don"t forget: convert the abundance to a decimal) (19. 9924 x 0. 904838) = 18. 0898 amu (20. 9940 x 0. 002696) = 0. 0565998 amu (21. 9914 x 0. 092465) = 2. 03343 amu. 18. 0898 + 0. 0565998 + 2. 03343 + = 20. 179 amu. The sum of all the atomic masses of each element in a compound measured in amu. Get rid of amu by using avogadro"s number: 6. 022 x 1023. Step 1: divide the calcium chloride formula units by avogadro"s number.