2 Gas Laws Flashcards
How is P1 and T1 related to P2 and T2?
P1 is pressure before
T1 is temperature before
P2 is pressure after
T2 is temperature after
Explain why a hot balloon expands
As temperature rises, the particles gain kinetic energy
Particles move faster
More collisions per unit time AND particles collide with more force
Pressure = force / area
Increased pressure on the inside of the balloon, with same pressure on the outside results in greater forces on inside compared to outside of balloon - balloon skin stretches outward
What are the control variables for the Boyles’ Law investigation where the volume of a gas was measured as the pressure was varied?
Moles/amount of gas
Temperature of gas
Use the equation below to calculate the new volume of a gas as its pressure increased from 100kPa to 200kPa.
Its initial volume was 50cm3.
P2V2 = P1 V1
V2 = P1V1/P2
V2 = 100kPa x 50cm3 / 200kPa
V2 = 25cm3
Convert 373K to ºC
ºC = 373 - 273
= 100ºC
Convert 100K to ºC
ºC = 100 - 273
= -173ºC
Name the independent and dependent variable for the Pressure-Temperature experiment
Independent : temperature gas
Dependent : pressure of gas
What happens to the pressure of a gas if the volume is halved?
Explain why this happens.
As volume is halved, pressure is doubled
There are double the number of particles per unit volume
Double the number of collision per unit time on the sides of the container
Double the force means double the pressure
P = F/A
Name the independent and dependent variable for Boyle’s law experiment
Independent : pressure
Dependent : volume of gas
What happens to the movement of the particles of a gas when they are heated?
The particles gain energy
KE of particles increases
Particles move faster
Convert 100ºC to Kelvin
K = 100 + 273
= 373 K
How would you represent the motion of a smoke particles in air? (Brownian motion)
Uses arrows of different length and directions to show continual random movement.
What is the unit for volume of a gas?
cm3 or m3
How many Pa are in a kPa?
1000 Pa = 1 kPa
From the graph, how is pressure of a gas related to its volume? (at constant temperature and moles of gas)
Pressure is inversely proportional to volume at constant temperature and moles of gas
Convert -273ºC to Kelvin
K = -273 + 273
= 0 K
A pupils stated that as the temperature of a gas in degrees celsius is doubles, the kinetic energy of the gas must also double.
Is this statement true or false?
False
At temperature of a gas in kelvin doubled, the average kinetic energy of the particles doubles
Temperature must be in kelvins!!