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Boyle’s Law

Robert Boyle 1621 - 1691

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Boyle’s Law Defined

Temperature is constant

Volume occupied by a gas varies inversely with the applied pressure

Equation:

P1V1 = P2V2

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P T V

If P , then V

If P , then V

Reminder:

Boyle’s Law has constant temp.

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Pressure vs. Volume

Pressure is inversely proportional to volume

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Solving Word Problems

Step 1. Write given information.

Example:

P1 = 1 atm

V1 = 40 mL

P2 = 2 atm

V2 = ?

Problem:

If the original pressure of a gas is 1 atm with a volume of 40 mL, what is the new volume when the pressure is increased to 2 atm?

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Solving Word Problems

Step 2: Use given information to determine what equation to use.

Example:

P1V1 = P2V2

Given Info:

P1 = 1 atm

V1 = 40 mL

P2 = 2 atm

V2 = ?

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Solving Word Problems

Step 3: Isolate the missing variable by re-arranging the equation Example: Isolate V2

P1V1 = P2V2 P1V1 = P2V2

P2 P2

Boyle’s Law Equation

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Solving Word Problems

Step 4: Plug-in the given values & solve.

Example

P1V1

P2

= V2

= V2

(1 atm)(40 mL)

(2 atm)

20 mL = V2

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Good Work!

Congratulations! You finished the first example problem using Boyle’s Law.

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Raise your hand if you feel like screaming?

Don’t worry …we’re not finished with Boyle’s law problems.

Let’s try a few more problems together on the chalkboard.