1. Mean (Average)
The mean is the total of all of the values divided by the number of values Example: Find the mean of 2, 3, 7, 7, 4 Step 1: = 23 Step 2: There are 5 numbers added together Step 3: Divide the total of the values (23) by the number of values (5) Answer: 23 / 5 = 4.6

2. Pressure
The force applied over a specific area. Common Units: Pounds per square inch (psi) Atmosphere (atm) Torr (torr) Pascal (Pa) Conversions: 1 atm = psi = 760 torr = Pa

3. Volume
The amount of space a sample of matter occupies. A cube with sides of 10 cm has a volume of: 10 cm x 10 cm x 10 cm = 1000 cm3 = 1000 mL = 1 L 1 cm3 = 1 mL Volume is often calculated using the water displacement method.

4. Temperature
A measure of the average kinetic energy of the atoms and molecules in a sample of matter. Common Units and Conversions: Degrees Fahrenheit (°F) °F = (9/5)°C + 32 Degrees Celsius (°C) °C = (5/9)(°F -32) Kelvin (K) K = °C + 273

5. Avogadro’s Law n = kV V1 n1 V2 n2 =
When temperature and pressure are held constant, the number of molecules (n) is equal to a constant (k) times the volume (V); therefore,
V1 n1
V2 n2 =

6. Charles’ Law
V = kT
When pressure is held constant, volume (V) is equal to a constant (k) times the temperature (T); therefore,
V1 V2
T1 T2 =

7. Boyle’s Law
PV = k
When temperature is held constant, pressure (P) times volume (V) is equal to a constant (k); therefore,
P1V1 = P2V2

8. Gay-Lussac’s Law P = kT P1 P2 T1 T2
When volume is held constant, pressure (P) is equal to a constant (k) times the temperature (T); therefore,
P1 P2
T1 T2 =

9. Proportional Relationship
A mathematically predictable relationship where one variable increases, another increases. Example: Boyle’s Law (PV = k) P ↑ V ↓ P ↓ T ↑

10. Inversely Proportional Relationship
A mathematically predictable relationship where one variable increases, another decreases. Examples: Charles’ Law (V = kT) V ↑ T ↑ V ↓ T ↓ Gay-Lussac’s Law (P = kT) P ↑ T ↑ P ↓ T ↓