Boyle's and Charles' Laws Flashcards
State Boyle’s Law
The pressure and volume of an ideal gas are inversely proportional when kept at a constant temperature
State Charles’ Law
The absolute temperature and volume of a gas are directly proportional when kept at a constant pressure
How would you measure the cross sectional area of inside of a syringe
- Remove the plunger and then using a micrometer measure the diameter of the seal
- This value can then be substituted into the circular area equation
Why should the clip used to seal the tubing coming from the syringe 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 is negligible in comparison to the volume in the syringe
Suggest how a mass hanger could be attached to the plunger of the syringe
- A small piece of string can be tied to the plunger to form a loop
- The hanger can then hook onot this loop
Why should the syringe be clamped above the region of the plunger’s motion
- Clamping the syringe can distort the barrel and hinder the motion of the plunger
- By clamping above the region in which the plunger moves, this problem is avoided
- It also ensures that the scale of the syringe isn’t covered by the clamp
Why should the syringe be clamped at a relatively high positon
The syringe should be clamped at a height so that the plunger has space to move downwards as masses are added
How can the force exerted by the masses by calculated
F = mg
Force = Mass x Gravitational Field Strength
How can the pressure exerted by the masses on the air sample be calculated
Pressure = Force / Cross Sectional Area of Plunger
The pressure should then be subtracted from the standard atmospheric pressure
State the value of standard atmospheric pressure
101 kPa
Describe the relationship that should be found when a graph of 1/V against P is plotted
Pressure and volume are inversely proportioanl so the graph of 1/V against P should be a straight line that passes through the origin
Suggest why a straight line may not be produced when plotting a graoh of 1/V against P
- The plunger may have experienced some resistance to its motion as masses were added
- This sticking of the plunger would create error that may result in an inaccurate measured change in volume
What safety precautions should be taken when using concentrated sulfuric acid
- Safety googles should be worn to ensure no acid enters your eyes
- Gloves could be worn to ensure there is no contact between the acid and your skin
What safety precautions should be taken when working with a hot beaker of water
- Avoid touching the hot beaker with bare hands, ensure it is handled with gloves and take care to avoid spillages
- A heatproof mat should be used to protect the bench
What should you do before recording each measurement of water temperature
- You should aways stir the water before taking a temperature measurement
- This means that the reading is an appropriate and accurate reflection of the average temperature of the water in the beaker