Chapter 8 – Chemical Quantities Test Topics
Thursday, December 2nd
 The mole and Avogadro’s # (1 mole = 6.02 x 1023 atoms, molecules,
ions or formula units)
 Representative units:
o ionic compounds (start with a metal) = formula units
o single element = atoms
o Element or elements with a positive or negative charge = ions
o molecular compounds, including diatomic molecules (start with
a nonmetal) = molecules
 Determining molar mass for elements and compounds (units for
molar mass are always grams/mole, g/mol) – round molar mass for
every element to 1 number after the decimal before multiplying.
 Determining # of moles, grams, atoms or ions from a given amount of
a compound
 Conversions between moles and atoms, molecules, ions, or formula
units (use 1 mol = 6.02 x 1023)
 Conversions between moles and grams (use 1 mol = molar mass in
grams for the element or compound)
 STP (Standard Temperature and Pressure) – 1 atm of pressure and
0oC (273 K) for the temperature
 Molar Volume of a Gas – at STP 1 mol = 22.4 L
 Conversions using molar volume (use 1 mol = 22.4 L) including
going between liters, grams, moles and atoms, molecules, ions &
formula units
 Calculating percent composition of an element in a compound
 Difference between empirical and molecular formulas
 Calculating empirical formulas given percents or grams for elements
 Calculating molecular formulas given the empirical formula and the
molar mass of the molecular compound
 Calculating both empirical and molecular formulas from percentages
or grams of each element. The molar mass of the molecular formula
will be given to you.