IMPORTANT CHEMICAL CONCEPTS: SOLUTIONS, CONCENTRATIONS, STOICHIOMETRY

IMPORTANT CHEMICAL CONCEPTS:
SOLUTIONS, CONCENTRATIONS, STOICHIOMETRY

I. Introduction

A. Course outline will be reviewed.
B. Laboratory experiments will be discussed in class.

II. Units of Measurement.
A. S.I. (Systeme International d Units).
1. The S.I. units consist of a minimum number of fundamental units, which do not
depend on position (or gravity). Unit system of units that does this is called a set of
"absolute" units.
2. S.I. Base (Fundamental) Units:
3. S.I. unit size can be changed at will by using metric prefixes:
B. S.I. unit for chemical quantity: the mole

1. The mole is also called Avogadro s number: 6.022 x 10+23.
2. A mole is defined as the number of carbon atoms in exactly 12.00 grams of carbon-
12.
3. The definition is selected so that the formula weight (in amu) and the molar mass (in
grams/mol) have the same numerical value.
4. For example: consider water, H2O
Formula Weight:
2 atoms H(1.0 amu/atom) = 2.0 amu
1 atom O(16.0 amu/atom) = 16.0 amu
Formula Weight = 18.0 amu/formula
Molar Mass = 18.0 grams/mol