Particle Model and pressure Flashcards
Medium
Give two reasons why taking repeat readings could provide more accurate data. [2]
Type of mistake: Understanding mistake
I don’t think I have studied the reasons why we take repated readings for an investigation and what will happen if we don’t. I don’t know the types of errors
Answer:
Reduces the effect of random errors.[1]
Allow the student to identify anomalies. [1]
Medium
Explain how the increased temperature would affcet the pressure exerted by the gas. [2]
Mistake: Misunderstanding principles and careless mistake.
I didn’t read the question properly and I didnt specified it to tempearure.
Answer: The pressure will increase in the tube[1] as the particles gain kinetic energy. [1]
Medium
What’s the equation of of pressure and volume when the gas is at constant temeprature?
Pressure x Volume = constant
P(1) x V (1) = P (2) x V (2)
A car tyre is inflated using a foot pump.
Explain why the internal energy of the air in the tyre increases as it is inflated [2]
Mistake: Apllication problem.
I dont understand what is work done and how it is applied.
Answer:
Work is done on the air in the tyre[1]
So the temperature of the air increases [1]
Medium
How will the volume affect the pressure[1]
As volume decreases pressure increases
Medium
Explain, in terms of particles, why the pressure in the gas increases as its volume decreases[4]
Mistake: I wasn’t specifc enough about what does the particles do to increase the pressure.
Answer:
As the volume decreases, the particles move close together.[1]
This causes more frequent collision of gas particles with the container walls.[1]
Each particle collision will cause a force [1]
so there is greater force in the wall[1]
Medium
Using ideas about the particles, explain how air inside a container exerts pressure[3]
Mistake: I didnt answer the question I tried to demonstarte that I understood the question instaed of answering what the question is asking.
Answer;
Particles collide with the walls of the container [1]
A force is produced by collisions of the particles with the walls.[1]
Pressure is force/area.[1]
Hard
As the gas expands into the space above the cream, its temperature decreases. Explain how this affects the pressure of the gas.[4]
Mistake:Application mistake.
This is because I haven’t related it to the equation Pressure= Force/Area
Answer:
This will decrease the gas temperature.[1][
The molecules have less kinetic energy. [1]
The collision with container walls are less frequent. [1]
There is smaller force. [1]
Hard
A student presses the button and some liquid leaves the can.
Explain what happens to the gas pressure in the spray - can as the gas leaves. [3]
Mistake: Misunderstanding principle. I thought that there will be less liquid particles will leave th can which means more gas particles that have high speed and cause more colllision.
Answer:
Gas presure in the gas decreases [1]
As the liquid leaves the number of of gas remian the same.[1]
The gas volume increases as it exapnds into the space left by the liquid.[1]
Hard
Explain why cooled ballon is smaller than warmer ones in terms of particles[4]
Particles move at lower kinetic energy[1]
on average[1]
Particles hit the sides of the container less frequently[1]
This redcues the forces which reduces the pressure [1]
