boyle’s law
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BOYLE’S LAW
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BOYLE’S LAW
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states that if the temperature is constant, as the pressure of the gas increases , the volume of a
contained gas decreases.
Do you know him ?
YES
NO
Robert Boyle is an English chemist that was the first
to determine the quantitative relationship.
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NEXTBACKBOYLE’S LAW EXPERIMENT
What is Boyle’s Law ?
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• Boyle’s Law is one of the laws in physics that concern the behaviour of gases
• When a gas is under pressure it takes up less space:
• The higher the pressure, the smaller the volume• Boyles Law tells us about the relationship between the volume of a gas and its pressure at a constant temperature
• The law states that pressure is inversely proportional to the volume
How can we write Boyle’s Law as a formula?
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• Pressure is inversely proportional to the volume and can be written as:
• Pressure a 1/volume
P=pressure in N/m2
V=volume in dm3 (litres)k=constant
• This is more usually written as:
• Pressure = constant volume
• PV=k• P1V1=P2V2
Boyle’s Law apparatus
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Pressure p Volume V P x V
1 40 44
2 26 52
3 20 60
4 17 68
Result of the experiment
What can you observe from this result ?
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RESULT OF THE EXPERIMENT• The pressure x volume for each set of
results remains constant• This is called Boyle’s Law• For a fixed mass of gas, at constant
temperature, pV = constant or P1 x V1 = P2 x V2
What can you conclude according to the result of the
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If you will plot the result, this will be
the outcome of your graph.
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• Curved lines are hard to recognise, so we plot the volume against the reciprocal of pressure (ie. 1/p)
• This time the points lie close to a straight line through the origin.
• This means volume is directly proportional to 1/pressure or
• volume is inversely proportional to pressure
EXAMPLE PROBLEMS
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A deep sea diver is working at a depth where
the pressure is 3.0 atmospheres. He is
breathing out air bubbles. The volume of each air bubble is 2 cm3. At the
surface the pressure is 1 atmosphere. What is the volume of each bubble
when it reaches the surface?
Follow these steps so that you can answer the problem easily :
1.) List first the given.
P1 – 3.0 atmV1 – 2cm3
P2 – 1 atm
Follow these steps so that you can answer the problem easily :
2.) Find the missing given.
V2
Follow these steps so that you can answer the problem easily :
3.) Write the formula.
P1 x V1 = P2 x V2
V2 = P1 x V1
P2
Follow these steps so that you can answer the problem easily :
4.) Solve the problem now.
V2 = P1 x V1
P2
V2 = 3.0 x 2 1.0
Follow these steps so that you can answer the problem easily :
5.) Write the answer now.
V2 = 6cm3
ACTBACK
Answer the following questions orally.
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Who is the chemist determine the quantitative relationship between the volume and pressure
of the gasses ?
State the Boyle’s Law.
ASSESSMENT
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Answer this problem ( 5 pts. ) and follow the steps to solve this problem :
A balloon with a volume of 2.0 L is filled with a gas at 3 atmospheres. If
the pressure is reduced to 0.5 atmospheres without a change in temperature, what would be the
volume of the balloon?NEXTBACK
BY :
TRISHA RACRAQUINIII-GOLD