SP9e Gas pressure and Volume

Question 1

Compression?

Answer 1

.pressure increased on a gas
.gas molecules are pushed closer together, reducing the volume they occupy

Question 2

Expansion?

Answer 2

.pressure decreased on a gas
.gas molecules have more space to move around, causing them to spread out and increase volume

Question 3

pressure = ?

Answer 3

force/area

Question 4

How does the pressure of a gas produce a force at right angles to any surface?

Answer 4

particles exert small forces at right angles to a surface creating a large net force at right angles to a surface.

Question 5

Assuming mass is constant, if temp is constant what happens to the speed of molecules?

Answer 5

doesn’t change.

Question 6

What does halving the volume of a container do to the pressure?

Answer 6

doubles the pressure because each particle now takes half the time to cross the container.

Question 7

p₁ x V₁ = ?

Answer 7

p₂ x V₂

Question 8

Is pressure directly or inversely proportional to volume?

Answer 8

inversely proportional.

Question 9

Why does doing work on a gas increase its temp? (use plunger and cotton thing as example) (4)

Answer 9

.pushing plunger transfers energy mechanically to air inside
.energy transferred as it is compressed is work done on the air - causes air particles to speed up
.faster particles have greater average KE - measured as higher temp
.air is compressed very quickly so no energy is lost - hot enough to ignite cotton