Standard Temperature and Pressure

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

Combined Gas law

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

Combined Gas law Variables

​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=​

    ​

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

    ​

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=​

    ​

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