1. PREPARING SOLUTIONS AND REAGENTS

2. Chemical Solutions (aqueous = water is the solvent)
Types of vessels (least to most precise):
Beaker
Erlennmeyer flask
Graduated cylinder
Volumetric flask

3. DEFINITIONS: SOLUTES -- substances that are dissolved
SOLVENTS -- substance in which solutes are dissolved (usually water)
AMOUNT -- how much

4. Goals Make solutions Dilute solutions
Convert between different concentrations of solutions

5. Facts of Life Mass is measured in Grams, mg, μg
1g = 1000mg = 1,000,000µg
Volume is measured in liters, mL, μL
1L = 1000mL = 1,000,000 μL
Density of water is 1 g / mL

6. Facts of life (cont’d)
Concentration means: amount of solute in a volume of solution

7. ? = 0.63 mg, so the concentration is 0.63 mg/mL
Each star represents 1 mg of NaCl.
What is the total amount of NaCl in the tube? _____
What is the concentration of NaCl in the tube (in mg/mL)? _____
5 mg = ?
8 mL mL
1mL x 5mg
————— = ? mg
8mL
? = 0.63 mg, so the concentration is
0.63 mg/mL
8 mL

8. Percent Solutions Per means “for every one” Cent means 100
Example: a 5% sugar solution has
5 grams of sugar for 100g of solution, or
5g g of water = 100 mL, and the
100mL solution is mostly water.

9. Procedure
1. Measure out 7.5g of lemonade and put in 75mL of water. (This is the solution)
2. Measure out 2.25g of lemonade and put it in 75mL of water. (This is the 30% dilution)

10. Questions 1. What was the solvent in the lab?
2. What was the solute in the lab?
3. Independent variable?
4. Dependent variable?
5. Constants?