Slide 1

Avogadros Principal & Molar Volume LG: I can use Avogadros Principal to equate volume and number of entities in a gas.

Slide 2

Avogadro's Principal Avogadro determined that different gases with equal volume, pressure, and temperature must contain the same number of particles

Slide 3

Avogadro's Principal (cont.) We can explain this using kinetic-molecular theory, but this concept was not understood in Avogadros time

Slide 4

Sample Problem 1 A balloon with a volume of 34.5 L is filled with 3.2 mol of helium gas. To what volume will the balloon expand is another 8.0 g of helium is added? (assuming pressure and temperature remain constant)

Slide 5

Molar Volume of a Gas Under standard conditions, 1 mole of a gas (any gas) will occupy a constant volume STP (0C and 101.3 kPa) = 22.4 L SATP (25C and 100 kPa = 24.8 L STP V = 22.4 L

Slide 6

Sample Problem 2 A sample of helium at SATP has a mass of 32.0 g. What volume does this mass of gas occupy?

Slide 7

Law of Combining Volumes Avogadros theory explained a previous observation about combining gases Joseph Gay-Lussac had previously observed that gases react in whole-number ratios (just like the coefficients in a balanced equation) Balanced Equation: 2 H 2 + O 2 2 H 2 O Mole Ratio: 2 : 1 : 2

Slide 8

Homework Text (Avogadros principal): Pg. 581 # 1 4 Read Section 12.4 Gas Mixtures and the law of Partial Pressures (Pg. 592-594) Explain what is meant by partial pressure using a specific example State Daltons law of partial pressures and include the formula Read sample problems 1 & 2 (on pg. 594) and complete practice problems # 1-4 that follow