Reading for Tuesday: Chapter Reading for Tuesday: Chapter Homework 11.1 – Due Tuesday 4/14/15 Homework 11.1 – Due Tuesday 4/14/15 Chapter 11 #'s 2, 4, 6, 10, 12, 13, 14, 18, 20, 24, 26, (even) Chapter 11 #'s 2, 4, 6, 10, 12, 13, 14, 18, 20, 24, 26, (even) Homework 11.2 – Due Thursday 4/16/15 Homework 11.2 – Due Thursday 4/16/15 Chapter 11 #'s 45, (even), (all), 68, 74, 76, 80, 82 Chapter 11 #'s 45, (even), (all), 68, 74, 76, 80, 82 Lab next Week – EXP 16 Lab next Week – EXP 16

Did you get it? A nitrogen gas sample occupies 50.5 mL at ºC and 1250 torr. What is the volume at STP?

Dalton’s law of partial pressures states that the total pressure of a gaseous mixture is equal to the sum of the individual pressures of each gas. Dalton’s law of partial pressures states that the total pressure of a gaseous mixture is equal to the sum of the individual pressures of each gas. P 1 + P 2 + P 3 + … = P total The pressure exerted by each gas in a mixture is its partial pressure, P n. The pressure exerted by each gas in a mixture is its partial pressure, P n.

An atmospheric sample contains nitrogen, oxygen, argon, and traces of other gases. If the partial pressure of nitrogen is 587 mmHg, oxygen is 158 mmHg, and argon is 7 mmHg, what is the observed pressure as read on the barometer?

We can measure the volume of a gas by displacement. We can measure the volume of a gas by displacement. By collecting the gas in a graduated cylinder, we can measure the amount of gas produced. By collecting the gas in a graduated cylinder, we can measure the amount of gas produced. The gas collected is referred to as “wet” gas since it also contains water vapor. The gas collected is referred to as “wet” gas since it also contains water vapor.

mL of hydrogen was collected over water on a day when the barometer read mmHg. The temperature of the wet gas was 25 o C. 1) What is the partial pressure of the gas? (vapor pressure of water at 25 o C is 23.8 mmHg)

mL of hydrogen was collected over water on a day when the barometer read mmHg. The temperature of the wet gas was 25 o C. 2) What is the volume of the gas at STP? PVP-ratio < 1 TVT-ratio < 1

mL of hydrogen was collected over water on a day when the barometer read mmHg. The temperature of the wet gas was 25 o C. 3) What was the mass of hydrogen collected?

An ideal gas is a gas that behaves in a predictable and consistent manner. An ideal gas is a gas that behaves in a predictable and consistent manner. Ideal gases have the following properties: Ideal gases have the following properties: gases are made up of very tiny molecules gases are made up of very tiny molecules gas molecules demonstrate rapid motion in straight lines and in random directions gas molecules demonstrate rapid motion in straight lines and in random directions gas molecules have no attraction for one another gas molecules have no attraction for one another gas molecules undergo elastic collisions gas molecules undergo elastic collisions the average kinetic energy of gas molecules is proportional to the Kelvin temperature, KE ∝ T the average kinetic energy of gas molecules is proportional to the Kelvin temperature, KE ∝ T Ideal Gas Law

Avogadro’s Law – Particles and Volume Particles and volume are directly proportional +

Ideal Gas Law almost there!!!!!! If we introduce a proportionality constant, R, we can write the equation:

Ideal Gas Law pressure (must be in atm) volume (must be in L) particles (must be in mol) temperature (must be in K)

Ideal Gas Law