Download presentation

Presentation is loading. Please wait.

Published byJustin Cullen Modified over 4 years ago

1
Ch. 14 - Gases III. Three More Laws Ideal Gas Law, Daltons Law, & Grahams Law

2
1 mol of a gas=22.4 L at STP Molar Volume at STP S tandard T emperature & P ressure 0°C and 1 atm A. Avogadros Principle

3
V n b Equal volumes of gases contain equal numbers of moles at constant temp & pressure true for any gas n = number of moles

4
PV T VnVn PV nT B. Ideal Gas Law = k UNIVERSAL GAS CONSTANT R=0.08206 L atm/mol K R=8.315 dm 3 kPa/mol K = R You dont need to memorize these values! Merge the Combined Gas Law with Avogadros Principle:

5
B. Ideal Gas Law UNIVERSAL GAS CONSTANT R=0.08206 L atm/mol K R=8.315 dm 3 kPa/mol K PV=nRT You dont need to memorize these values!

6
GIVEN: P = ? atm n = 0.412 mol T = 16°C = 289 K V = 3.25 L R = 0.0826 L atm/mol K WORK: PV = nRT P(3.25)=(0.412)(0.0821)(289) L mol L atm/mol K K P = 3.01 atm C. Ideal Gas Law Problems b Calculate the pressure in atmospheres of 0.412 mol of He at 16°C & occupying 3.25 L.

7
GIVEN: V = ?V = ? n = 85 g T = 25°C = 298 K P = 104.5 kPa R = 8.315 dm 3 kPa/mol K C. Ideal Gas Law Problems b Find the volume of 85 g of O 2 at 25°C and 104.5 kPa. = 2.7 mol WORK: 85 g 1 mol O 2 = 2.7 mol 32.00 gO 2 PV = nRT (104.5)V=(2.7) (8.315) (298) kPa mol dm 3 kPa/mol K K V = 64 dm 3

8
D. Applications of Ideal Gas Law b Can be used to calculate the molar mass of a gas from the density b Substitute this into ideal gas law b And m/V = d in g/L, so

9
GIVEN: P = 1.50 atm T = 27°C = 300. K d = 1.95 g/L R = 0.08206 L atm/mol K MM = ? WORK: MM = dRT/P MM=(1.95)(0.08206)(300.)/1.50 g/L L atm/mol K K atm MM = 32.0 g/mol D. Applications of Ideal Gas Law b The density of a gas was measured at 1.50 atm and 27 ° C and found to be 1.95 g/L. Calculate the molar mass of the gas.

10
GIVEN: d = ? g/L CO 2 T = 25°C = 298 K P = 750. torr R = 0.08206 L atm/mol K MM = 44.01 g/mol MM = dRT/P d = MM P/RT d=(44.01)(.987)/(0.08206)(298) g/mol atm L atm/mol K K d = 1.78 g/L CO 2 D. Applications of Ideal Gas Law b Calculate the density of carbon dioxide gas at 25 °C and 750. torr. WORK: 750 torr 1 atm =.987 atm 760 torr =.987 atm

11
D. Daltons Law b The total pressure of a mixture of gases equals the sum of the partial pressures of the individual gases P total = P 1 + P 2 +...P n

12
GIVEN: P O2 = ? P total = 1.00 atm P CO2 = 0.12 atm P N2 = 0.70 atm WORK: P total = P CO2 + P N2 + P O2 1.00 atm = 0.12 atm +.70 atm + P O2 P O2 = 0.18 atm D. Daltons Law b A sample of air has a total pressure of 1.00 atm. The mixture contains only CO 2, N 2, and O 2. If P CO2 = 0.12 atm and P N2 = 0.70, what is the partial pressure of O 2 ?

13
D. Daltons Law When H 2 gas is collected by water displacement, the gas in the collection bottle is actually a mixture of H 2 and water vapor. Water exerts a pressure known as water-vapor pressure So, to determine total pressure of gas and water vapor inside a container, make total pressure inside bottle = atmosphere and use this formula: P atm = P gas + P H 2 O

14
GIVEN: P H2 = ? P total = 94.4 kPa P H2O = 20.4 mm Hg = 2.72 kPa WORK: P total = P H2 + P H2O 94.4 kPa = P H2 + 2.72 kPa P H2 = 91.7 kPa D. Daltons Law b Hydrogen gas is collected over water at 22.5°C. Find the pressure of the dry gas if the atmospheric pressure is 94.4 kPa. Look up water-vapor pressure for 22.5°C, convert to kPa Sig Figs: Round to lowest number of decimal places. The total pressure in the collection bottle is equal to atmospheric pressure and is a mixture of H 2 and water vapor.

15
GIVEN: P gas = ? P total = 742.0 torr P H2O = 42.2 torr WORK: P total = P gas + P H2O 742.0 torr = P H2 + 42.2 torr P gas = 699.8 torr b A gas is collected over water at a temp of 35.0°C when the barometric pressure is 742.0 torr. What is the partial pressure of the dry gas? Look up water-vapor pressure for 35.0°C. Sig Figs: Round to least number of decimal places. D. Daltons Law The total pressure in the collection bottle is equal to barometric pressure and is a mixture of the gas and water vapor.

Similar presentations

Presentation is loading. Please wait....

OK

PV = nRT.

PV = nRT.

© 2018 SlidePlayer.com Inc.

All rights reserved.

To ensure the functioning of the site, we use **cookies**. We share information about your activities on the site with our partners and Google partners: social networks and companies engaged in advertising and web analytics. For more information, see the Privacy Policy and Google Privacy & Terms.
Your consent to our cookies if you continue to use this website.

Ads by Google

Economics ppt on lpg A ppt on presentation skills Ppt on monitoring and evaluation Ppt on javascript events ios Ppt on viruses and anti viruses test Ppt on different types of forests in the philippines Ppt on water pollution download Ppt on solar energy in hindi Ppt on job evaluation method Perspective view ppt online