GAS LAWS

Question 1

1. What are the 4 variables that determine Gas Behaviour?

Answer 1

1. Volume (V)
2. Pressure (P)
3. Temperature (T)
4. Amount (n)

Question 2

2. What do Gas Laws investigate?

Answer 2

• the relationship between the four variables that
  determine Gas Pressure
  (volume, pressure, temperature and amount)

Question 3

3. What are the constants in Boyle’s Law?

Answer 3

• constant temperature (T)
• constant amount (n)

Question 4

4. What is Volume proportional to in Boyle’s Law?

Answer 4

• Volume (V) is proportional to 1/P
• an increase in volume will lead to a decrease in
  pressure
• P and V = k
  = this is at constant temperature and
  amount

Question 5

5. Why do we keep the temperature constant during Boyle’s Law?

Answer 5

• this makes sure that the average particle speed is
  constant
• this keeps the number of the moles constant
• this is done by having a sealed container

Question 6

6. Why do we keep the temperature constant during Boyle’s Law?

Answer 6

• this makes sure that the average particle speed is
  constant
• this keeps the number of the moles constant
• this is done by having a sealed container

Question 7

7. How can we increase the pressure of the enclosed gas?

Answer 7

• we can do this by placing more weights on the top
  surface of the container
• the increasing weight increases the force
• the increased force increases the pressure

Question 8

8. What does an increase in the pressure result in?

Answer 8

• a decrease in the volume
• the pressure and the volume are inversely
  proportional

Question 9

9. What is kept constant in Charles’ Law?

Answer 9

• the pressure is kept constant
• the amount/moles are kept constant

Question 10

10. What is Volume proportional to in Charles’ Law?

Answer 10

• it is proportional to the Temperature (T)
• an increase in temperature will increase the volume
• V / T = k
  = at a constant Amount and Pressure

Question 11

11. How do we keep the pressure constant in Charles’ Law?

Answer 11

• the weight of the piston is kept the same
• the number of the moles is kept constant
• this is a result of the container being sealed

Question 12

12. What happens when we increase the temperature in Charles’ Law?

Answer 12

• the gas particles move faster
• they collide with the piston with more force
• they collide with more intensity
• they collide with a higher frequency

Question 13

13. What happens if the collisions with the piston have a higher frequency and higher intensity in Charles’ Law?

Answer 13

• the piston will move upwards
• this makes sure that the pressure does not increase
• this is because the pressure must remain constant
• this increases the volume of the container

Question 14

14. What happens if we extrapolate the plots to a volume of zero?

Answer 14

• we find on the x-axis the lowest possible temperature
  that can be achieved in the universe
• this temperature is called Absolute Zero
• this is found to be at -273.15°C
• this is called Zero degrees in Kelvin
• there is now lower temperature than this

Question 15

15. What factors are constant in Avogadro’s Law?

Answer 15

• pressure is constant (P)
• temperature is constant (T)

Question 16

16. What is Volume proportional to in Avogadro’s Law?

Answer 16

• the moles
• this is the amount of the substance
• V / n = k
  = this is at constant temperature and pressure

Question 17

17. What does an ideal gas conform to?

Answer 17

THE THREE GAS LAWS:
- Boyle’s Law
- Charles’ Law
- Avogadro’s Law

Question 18

18. What is an Ideal Gas?

Answer 18

• it is a gas in which the gas particles are separated by
  large distances
• there are no interactions between the particles

Question 19

19. What are the two conditions for Ideal Gas Behaviour?

Answer 19

1. Pressure Conditions:
   
   • Low Pressure
2. Temperature Conditions
   
   • High Temperature

Question 20

20. Why is a Low Pressure necessary for an Ideal Gas?

Answer 20

• the low pressure means that there are very few gas
  particles
• these particles are far apart
• they experience no interactions

IN HIGH PRESSURE:
- the gas particles start to move closer to one another

Question 21

21. Why are High Temperatures necessary for an Ideal Gas?

Answer 21

• the gas particles have enough kinetic energy to
  overcome any attractive forces
• these attractive forces want to keep the particles
  together
• these particles will not stick together when they
  collide

Question 22

22. How is the volume of an Ideal Gas worked out?

Answer 22

• it can also be worked out by: PV = nRT

Question 23

23. What do each of the variables of this equation represent?

Answer 23

R = Gas Constant
= 0.08206 L atm/mol K
= 8.3145 J/mol K

T = Temperature
= this must always be in degrees Kelvin
= T (Celsius) + 273.15

Question 24

24. What are the conditions of the Ideal Gas Law?

Answer 24

STANDARD TEMPERATURE:
- 0°C

STANDARD PRESSURE (STP):
- 1 atm

MOLAR VOLUME (OF ANY GAS):
- 22.414 L

Question 25

25. Answer this question.

Answer 25

Question 26

26. Read through this summary.
    Does everything make sense?

Answer 26

• yes