1. Chapter 11: The Behavior of Gases
Section 2:
The Gas Laws

2. Robert Boyle- Boyle’s Law
Pressure and Volume
Boyle’s Law states that the pressure and volume of a gas at constant temperature are inversely proportional
P1V1 = P2V2
If pressure of gas ↑ - volume of gas ↓
If pressure of gas ↓ - volume of gas ↑
If volume of gas ↑ - pressure of gas ↓
If volume of gas ↓ - pressure of gas ↑
According to the kinetic theory, if the temperature of a gas is constant and the gas is compressed, its pressure must rise

3. http://education- portal
portal.com/academy/lesson/boyles- charles-gay-lussacs-laws-pressure- volume-and-temperature- relationships.html#lesson

4. Inverse Proportion

5. Boyle’s Law Practice problems
1) mL of methane gas at 700 mm Hg
? mL of methane gas at 760 mm Hg
Use P1V1 = P2V2
(700 mm Hg) 60 mL = (760 mm Hg) ? mL
? mL = 55.3 mL

6. Boyles Practice 2) 1000 L at 1.0 atm ? L at 5.0 atm Use P1V1 = P2V2
Use P1V1 = P2V2
1.0 atm (1000 L) = 5.0 atm (? L )
? L = 200 L

7. Jacques Charles -Charles’s Law:
Temperature and Volume
Charles’s Law states that at constant pressure, the volume of a gas is directly proportional to its Kelvin temperature
V1 = V2
T T2
If volume increase, temperature increases (vice-versa)
If volume decreases, temperature decreases (vice-versa)

8. http://education- portal
portal.com/academy/lesson/charles-law- gas-pressure-and-temperature- relationship.html#lesson

9. Charles Law direct proportion

10. Charles’s Law Practice Problems
1) 3.0 L of He at 310 K
? L of He at 340 K
use V1 = V L = ? L
T T K K
? L = (340K) 3.0L = L
310 K

11. Charles Law Problems Cont
2) 4.0 L of methane at 30.0°C
? L of methane at 0°C
First convert °C to K: (Tk = Tc + 273)
0°C = 273 K
30.0°C = = 303K
use V1 = V L = ? L
T T K K
? L = (273 K) 4.0L = L
303 K

12. COMBINED GAS LAW Combination of Boyle’s Law and Charles’s Law
You can solve for one variable (P, V or T), regardless of the order in which the other two changed.
P1V1 = P2V2
T T2
The set conditions for the combined gas law problems are °C and 1 atm- called STANDARD TEMPERATURE AND PRESSURE or STP

13. 1) 2.7 L N2 at 121 kPa and 288 K ? L N2 at 202 kPa and 303K Use P1V1 = P2V2 T1 T2 121 kPa (2.7 L) = 202kPa ( ? L ) 288 K 303 K L ·kPa = 202kPa ( ? L) 288 K 303 K 1.13 L ·kPa = 0.66 kPa (? L) K K ? L = 1.70 L

14. LAW OF COMBINING GAS VOLUMES
The observation that at the same temperature and pressure, volumes of gases combine or decompose in ratios of small whole numbers
Gas Reactions show that volumes of gases always react in ratios of small whole numbers
portal.com/academy/lesson/daltons-law-of- partial-pressures-calculating-partial-total- pressures.html#lesson

15. Amedeo Avogadro
First to interpret the law of combining volumes in terms of interacting particles
The volume of a gas at a given temperature and pressure depends on the number of gas particles
AVOGRADO’S PRINCIPLE states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles
portal.com/academy/lesson/molar-volume- using-avogadros-law-to-calculate-the- quantity-or-volume-of-a-gas.html#lesson