PAG 8.2 Investigating the Relationship between Pressure and Volume Flashcards
State Boyle’s Law
When kept at a constant temp the pressure and volume of an ideal gas are inversely proportional
pV = constant
How is the cross sectional area of the syringe measured
Remove the plunger and using a micrometer, measure the diameter and sub into area of circle equation
Who should the clip used to seal the tubing come from the syring be as close to the syringe tip as possible
The volume of air trapped in the tubing should be as small as possible so that it is negligible in comparison to volume of syringe
Suggest how a mass hanger could be attached to the plunger of the syringe
A small piece of string and hanger can be hooked onto a loop
Why should the syringe be clamped above the region of the plunger’s motion
Can distort the barrel and hinder the motion of the plunger, so clamp above to avoid
Also ensure clamp is not covering scale
Why should the syringe be clamped at a sufficiently high height?
Plunger has space to move downwards as masses are added
How can the force exerted by the masses be calculated
F = mg
How can the pressure exerted by the masses on the air be calculated?
P = F/A
Pressure should then be subtracted from atmospheric pressure
State the value of standard atmospheric pressure
101kPa
Describe the relationship that should be found when a graph of 1/V against P is plotted
Pressure and Volume are inversely proportional so the graph of 1/V against P should be a straight line that passes through the origin
Why should the volume be changed slowly when carrying out this experiment?
So temperature remains constant so Boyle’s law can hold
What happens to the air trapped by the oil when the pressure exerted by the oil increases?
As the pressure on the oil increases, the air is compressed ands its volume decreases
How can the volume of air be measured?
If the sealed tube has a length scale, the length of the column can be multiplied by the circular air of the tube
Why would it not be suitable to take volume measurements for decreasing pressures rather than increasing pressures
If you decrease the pressyre of the oil, levek would be lower and volume would increase.
Some oil would cling to the tube, resulting in volume readings that are too large
Describe the technique for measuring the height of the oil
Measurements should be taken at eye level to the oil’s surface, Value from the bottom of the meniscus
