Chemical Quantities

Chapter Objectives
At the end of this unit students will be able to
1.  describe methods of measuring the amount of something.
2.  define Avogadro's number as it relates to a mole of a substance.
3.  distinguish between the atomic mass of an element and its molar mass.
4.  describe how the mass of a mole of a compound is calculated.
5.  describe how to convert the mass of a substance to the number of moles of a substance and moles to mass.
6.  identify the volume of a quantitu of gas at STP.
7.  describe how to calculate the percent by mass of an element in a compound.
8.  interpret an empirical formula.
9.  distinguish between empirical and molecular forumlas.

Key Terms
Avogadro's number
empirical forumla
molar mass
molar volume
mole (mol)
percent composition
representative particle
standard temperature and pressure (STP