1. Solutions!!!
Chem 332 – O’Dette

2. What is a solution? A homogeneous mixture of a solute and solvent
Solvent : major component, largest component of substance present
Solute : minor component
Solution : solute + solvent

3. Solutions Type Example Solvent Solute Gas Air N2 (78%) O2 (21%) Liquid
Vinegar
H2O
Acetic Acid
Solid
Brass
Cu (70%)
Zn (30%)

4. Molarity (M) Molarity = moles of solute
Used to express the concentration of a solution using specific units
Used as a conversion factor to calculate moles and volume
liters of solution

5. Example #1
3.0 moles of KBr are present in 0.40 L of solution. Find the molarity.
3.0 moles KBr
7.5 moles KBr
7.5 M KBr = =
0.40 L KBr
1 L KBr

6. Example #2
Find the number of moles of the solute in 2 L of a 3.0 M NaCl solution.
C.F. = 3.0 moles NaCl
1 L NaCl
2 L NaCl
3 moles NaCl =
6 moles NaCl x
1 L NaCl

7. Example # 3
What volume of solution can be made from 6 moles KNO3 to produce a 0.60 M concentration?
Conversion Factor
6 moles KNO3 x
1 L KNO3 =
10 L KNO3
0.60 mole KNO3