Required Practical 8

Question 1

Equipment for Boyle’s law investigation

Answer 1

Stand and clamp
Syringe
Vernier clips
100g masses and holder

Question 2

Atmospheric pressure

Answer 2

101kPa

Question 3

How do you convert bars to pascals

Answer 3

1 bar = 100kPa

Question 4

Control for Boyle’s law

Answer 4

Temperature

Mass

Question 5

Cross sectional area of syringe

Answer 5

pi x 0.5d^2

Question 6

How do you record pressure

Answer 6

Pressure gauge

Question 7

Safety issues for investigating Boyle’s law

Answer 7

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

Question 8

Boyle’s law experiment method

Answer 8

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

Question 9

What gases obey Boyle’s and Charles’ law

Answer 9

Ideal gases

Question 10

Charles’ law experiment equipment

Answer 10

Hot water
Kettle
Beaker
Thermometer
Air bubble trapped in a capillary tube

Question 11

Risk assessment for Charles’ law experiment

Answer 11

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

Question 12

Control variable for Charles’ law experiment

Answer 12

Pressure and mass

Question 13

Method for investigating Charles’ law

Answer 13

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

Question 14

Systematic error in this experiment

Answer 14

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