Required Practical 8 Flashcards
Equipment for Boyle’s law investigation
Stand and clamp
Syringe
Vernier clips
100g masses and holder
Atmospheric pressure
101kPa
How do you convert bars to pascals
1 bar = 100kPa
Control for Boyle’s law
Temperature
Mass
Cross sectional area of syringe
pi x 0.5d^2
How do you record pressure
Pressure gauge
Safety issues for investigating Boyle’s law
Using pressurised glass container so wear googles and don’t use too high of a pressure
Stand could topple and cause injury so use a counterweight and secure safely to desk
Boyle’s law experiment method
Air bubble trapped in oil in a sealed tube of fixed dimensions
Measure the volume of air at atmospheric pressure by multiplying the length of the part containing air by the radius of the tube squared and pi
Gradually increase pressure by set intervals at a constant temperature
Record pressure and volume each interval
Repeat 5 times and calculate a mean value of volume for each pressure
Plot a graph of pressure (y) against 1/volume (x) and it should be a straight line that passes through the origin
What gases obey Boyle’s and Charles’ law
Ideal gases
Charles’ law experiment equipment
Hot water Kettle Beaker Thermometer Air bubble trapped in a capillary tube
Risk assessment for Charles’ law experiment
Boiling water, safer to use kettle than Bunsen burner
Sulfuric acid drop may escape and cause acid burns so wear gloves and goggles
Stand up and don’t sit down in case it spills
Control variable for Charles’ law experiment
Pressure and mass
Method for investigating Charles’ law
A capillary tube containing a drop of sulfuric acid half way up a sealed tube so that a small column of air is trapped between the bottom and the acid drop
Place in a beaker of hot water
Position a ruler behind so you can measure the length of the air column
Record the temperature and the length as it cools
Repeat 5 times and calculate a mean length for each temperature
Plot a graph of temperature against volume
Where volume is equal to the radius squared times by pi and the length of the air column
Systematic error in this experiment
Volume is always slightly more than what is recorded
Due to the air in the little tube at the start
Can fix by seeing how much water it takes to fill to 20ml and subtracting the 20ml from this
