11.3 Gas Laws (Combined)

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Gas Laws

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• Boyle's Law

• Charles’s Law

• Combined, Avogadro's, Ideal

• Dalton's Law Partial Pressures

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Standard Temperature and Pressure

STP
temperature of 0.00°C or 273 K and a pressure of 1.00 atm.

Multiple Choice

Standard temperature is defined as

• 0.0 K

• 273 K

• 273°C

Multiple Choice

Standard pressure is defined as

• 1.00 atm

• 870 mmHg

• 0.00 atm

Combined Gas law

The combination of Boyle's Law and Charles's Law is called the Combined Gas Law

Combined Gas law Variables

​	​Symbol	​Units
​Pressure	​P	​atm, Pa (kPa), torr, mmHg, Bar, psi, at
​Temperature	​T	​C converts to K
​Volume	​V	​L, mL, m3, cm3

​Temperatures in C +273 = K
ALWAYS check that your variables match!
P1 cannot be in atm and P2 in torr

Combined Gas Law

• A helium balloon has a volume of 50.0 L at 25°C and 1.08 atm. What Volume will it have at 0.855 atm and 10°C?

  • Step one Identify all the information we have

    • V₁=

    • P₁=

    • T₁=

    • V₂=

    • P₂=

    • T₂=​

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Combined Gas Law

• A helium balloon has a volume of 50.0 L at 25°C and 1.08 atm. What Volume will it have at 0.855 atm and 10°C?

  • Step one Identify all the information we have

    • V₁= 50.0

    • P₁=1.08

    • T₁=298

    • V₂=

    • P₂=0.855

    • T₂=​283

  • Step 2: Plug in our values to solve

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Combined Gas Law

• The volume of a gas at 27°C and 0.2 atm is 80 mL. What Volume will it have at standard conditions?

  • Step one Identify all the information we have

    • V₁=

    • P₁=

    • T₁=

    • V₂=

    • P₂=

    • T₂=​

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Combined Gas Law

• The volume of a gas at 27°C and 0.2 atm is 80 mL. What Volume will it have at STP conditions?

  • Step one Identify all the information we have

    • V₁= 80

    • P₁=0.2

    • T₁= 27 + 273 = 300 K

    • V₂=

    • P₂= 1 atm

    • T₂=​ 0 + 273= 273 K

  • Step two: Plug in your values and solve