GAS LAWS Flashcards
1
Q
- What are the 4 variables that determine Gas Behaviour?
A
- Volume (V)
- Pressure (P)
- Temperature (T)
- Amount (n)
2
Q
- What do Gas Laws investigate?
A
- the relationship between the four variables that
determine Gas Pressure
(volume, pressure, temperature and amount)
3
Q
- What are the constants in Boyle’s Law?
A
- constant temperature (T)
- constant amount (n)
4
Q
- What is Volume proportional to in Boyle’s Law?
A
- 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
5
Q
- Why do we keep the temperature constant during Boyle’s Law?
A
- 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
6
Q
- Why do we keep the temperature constant during Boyle’s Law?
A
- 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
7
Q
- How can we increase the pressure of the enclosed gas?
A
- 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
8
Q
- What does an increase in the pressure result in?
A
- a decrease in the volume
- the pressure and the volume are inversely
proportional
9
Q
- What is kept constant in Charles’ Law?
A
- the pressure is kept constant
- the amount/moles are kept constant
10
Q
- What is Volume proportional to in Charles’ Law?
A
- it is proportional to the Temperature (T)
- an increase in temperature will increase the volume
- V / T = k
= at a constant Amount and Pressure
11
Q
- How do we keep the pressure constant in Charles’ Law?
A
- 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
12
Q
- What happens when we increase the temperature in Charles’ Law?
A
- the gas particles move faster
- they collide with the piston with more force
- they collide with more intensity
- they collide with a higher frequency
13
Q
- What happens if the collisions with the piston have a higher frequency and higher intensity in Charles’ Law?
A
- 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
14
Q
- What happens if we extrapolate the plots to a volume of zero?
A
- 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
15
Q
- What factors are constant in Avogadro’s Law?
A
- pressure is constant (P)
- temperature is constant (T)
16
Q
- What is Volume proportional to in Avogadro’s Law?
A
- the moles
- this is the amount of the substance
- V / n = k
= this is at constant temperature and pressure
17
Q
- What does an ideal gas conform to?
A
THE THREE GAS LAWS:
- Boyle’s Law
- Charles’ Law
- Avogadro’s Law
18
Q
- What is an Ideal Gas?
A
- it is a gas in which the gas particles are separated by
large distances - there are no interactions between the particles
19
Q
- What are the two conditions for Ideal Gas Behaviour?
A
- Pressure Conditions:
- Low Pressure
- Temperature Conditions
- High Temperature
20
Q
- Why is a Low Pressure necessary for an Ideal Gas?
A
- 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
21
Q
- Why are High Temperatures necessary for an Ideal Gas?
A
- 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
22
Q
- How is the volume of an Ideal Gas worked out?
A
- it can also be worked out by: PV = nRT
23
Q
- What do each of the variables of this equation represent?
A
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
24
Q
- What are the conditions of the Ideal Gas Law?
A
STANDARD TEMPERATURE:
- 0°C
STANDARD PRESSURE (STP):
- 1 atm
MOLAR VOLUME (OF ANY GAS):
- 22.414 L
25
Q
- Answer this question.
A
26
Q
- Read through this summary.
Does everything make sense?
A
- yes
