vanden bout/labrake/crawford ch301 gas laws - day 3

CH301 Vanden Bout/LaBrake Fall 2013

VandenBout/LaBrake/Crawford

CH301

GAS LAWS - Day 3


Important Information

HW2 POSTED - DUE TUE MORNING 9AMLM6 & 7 POSTED – DUE TUE MORNING 9AM

LM2,3,4 & 5 WERE DUE THIS MORNING 9AM

Unit1Day3-LaBrakeWednesday, September 04, 20135:19 PM

Unit1Day3-LaBrake


What are we going to learn today?

MACROSCOPIC & MICROSCOPIC VIEWS OF GASESIDEAL GAS LAW

USE IDEAL GAS LAW – IDENTIFY UNKOWN GAS


QUIZ: CLICKER QUESTION 1 (points for CORRECT answer)

According to Avagadro’s Law, a sample of H2

gas with a volume of 10 liters, at a pressure of 2 atm, and a temperature of 25°C, contains ________ “particles” compared to a sample He gas that has a volume of 5 L at the same temperature and pressure.

A. the same number ofB. two times moreC. four times moreD. two times lessE. four times less

CH301 Vanden Bout/LaBrake Fal 2013

Which of the following is a plot of the pressure of a gas as a function of the volume at fixed temperature?


A B

C D

Unit1Day3-LaBrake

CH301 Vanden Bout/LaBrake Fal 2013

Which of the following is a plot of the pressure of a gas as a function of the volume at fixed temperature?


A B

C D


Describe a Gas

PHYSICAL DESCRIPTION:

VOLUMEPRESSURE – most abstract property

TEMPERATUREAMOUNT

GAS LAWs QUANTIFY THE RELATIONSHIP OF THE PROPERTIES. EQUATION FORM OF LAWs GIVE

ABILITY TO PREDICT CONDITIONS AT NEW STATE

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CH302 Vanden Bout/LaBrake Spring 2012

You have a sample of O2 gas T = 10°C and a P = 1 atm. If you increase T = 20°C and keep P = 1 atm, V will:

A. stay the sameB. be slightly higher but not double the originalC. double compared to the original volumeD. decrease slightly but not in half the originalE. decrease to half the original volume

POLL: CLICKER QUESTION 3


TRY IT - Balloon in ice water… balloon in liquid N2


COMPARE COLD BALLOON TO BALLOON IN VACUUM

COMPARE MACROSCOPIC VIEW WITH MICROSCOPIC VIEW

http://ch301.cm.utexas.edu/simulations/gas-laws/GasLawSimulator.swf

Unit1Day3-LaBrake


COMPARE COLD BALLOON TO BALLOON IN VACUUM

COMPARE MACROSCOPIC VIEW WITH MICROSCOPIC VIEW

http://ch301.cm.utexas.edu/simulations/gas-laws/GasLawSimulator.swf


Think back to the syringe investigation: When the VOLUME of the container is DECREASED, and the T and amount of gas remains the same, the PRESSURE:

a)PRESSURE INCREASESb)PRESSURE DOES NOT CHANGEc)PRESSURE DECREASESd)PRESSURE WILL CHANGE BRIEFLY, BUT THEN RETURNS TO ORIGINAL PRESSURE

POLLING: CLICKER QUESTION 4


Think back to the syringe investigation: When the VOLUME of the container is DECREASED, and the T and amount of gas remains the same, the PRESSURE INCREASES. The small particle explanation is because the:

a)# of collisions INCREASESb)# of collisions DOES NOT CHANGEc)# of collisions DECREASESd)Avg speed of particles DECREASESe)Avg speed of particles DOES NOT CHANGE


Unit1Day3-LaBrake


Think back to the syringe investigation: When the VOLUME of the container is DECREASED, and the T and amount of gas remains the same, the PRESSURE INCREASES. The small particle explanation is because the:

a)# of collisions INCREASESb)# of collisions DOES NOT CHANGEc)# of collisions DECREASESd)Avg speed of particles DECREASESe)Avg speed of particles DOES NOT CHANGE



Think back to the balloon in liquid N2 demonstration : When the TEMPERATURE of the container is DECREASED, and the P and amount of gas remains the same, the :

a)VOLUME INCREASESb)VOLUME DOES NOT CHANGEc)VOLUME DECREASESd)VOLUME WILL CHANGE BRIEFLY, BUT THEN RETURNS TO ORIGINAL VOLUME


Unit1Day3-LaBrake


Think back to the balloon in liquid N2 demonstration : When the TEMPERATURE of the container is DECREASED, and the P and amount of gas remains the same, THE VOLUME DECREASES - the small gas particle explanation is because the:

a)AVG SPEED OF PARTICLES DECREASESb)AVG SPEED OF PARTICLES INCREASESc)AVG SPEED OF PARTICLES DOES NOT CHANGE



MACROSCOPIC DESCRIPTION

MICROSCOPIC MODEL (SMALL PARTICLE MODEL)

EMPERICALLY DERIVED MODELS


COMBINE GAS LAWS – IDEAL GAS LAW

PV = nRT

The value of R depends on the units of

measure used for the State Functions

R = .08205746 L atm K−1 mol−1

R = .08314472 L bar K−1 mol−1

Unit1Day3-LaBrake


COMBINE GAS LAWS – IDEAL GAS LAW

PV = nRT

The value of R depends on the units of

measure used for the State Functions

R = .08205746 L atm K−1 mol−1

R = .08314472 L bar K−1 mol−1


COMBINE GAS LAWS – IDEAL GAS EQUATION

PV = nRT

THIS IS ACTUALLY QUITE COOL


USEFULLNESS?

PV = nRT

Given 3 properties of the state, calculate the 4th.

Predicts every single gas should have the same number density.

Same P, T should be identical – moles per volume (# density).

Molar volume – volume per one mole useful for gas stoichiometry.

Particles have different masses, different gases should have different

mass densities under same conditions.

Given P, T and molar mass – calculate mass density of a gas.

Given P, T and density – calculate the molar mass of a gas.

Unit1Day3-LaBrake


USEFULLNESS?

PV = nRT

Given 3 properties of the state, calculate the 4th.

Predicts every single gas should have the same number density.

Same P, T should be identical – moles per volume (# density).

Molar volume – volume per one mole useful for gas stoichiometry.

Particles have different masses, different gases should have different

mass densities under same conditions.

Given P, T and molar mass – calculate mass density of a gas.

Given P, T and density – calculate the molar mass of a gas.



Which balloon has the higher mass density?

A. ArB. HeC. they are the same

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Which balloon has the higher number density?




We have two identical containers held at the same T, one contains Ar, one contains He. The containers have the same mass density. Which has the higher pressure?


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GROUP WORK

Starting with the ideal gas law and the molar mass of a gas, derive an equation

for the mass density of a gas.



GROUP WORK

The oil produced from eucalyptus leaves contains the volatile organic compound eucalyptol. At 190 ºC and 60.0 Torr, a sample of eucalyptol vapor had a density of 0.320 g*L-1. Calculate the molar mass of eucalyptol. Unit1Day3-LaBrake


GROUP WORK

The oil produced from eucalyptus leaves contains the volatile organic compound eucalyptol. At 190 ºC and 60.0 Torr, a sample of eucalyptol vapor had a density of 0.320 g*L-1. Calculate the molar mass of eucalyptol.


GROUP WORK QUIZ CLICKER QUESTION

The oil produced from eucalyptus leaves contains the volatile organic compound eucalyptol. At 190 ºC and 60.0 Torr, a sample of eucalyptol vapor had a density of 0.320 g*L-1. Calculate the molar mass of eucalyptol..

a)63 g/molb)154 g/molc)0.01 g/mold)10 g/mol



Calculate the volume of carbon dioxide, adjusted to 25 ºC and 1.0 atm , that plants need to make 1.00 g of glucose.

6CO2 (g) + 6H2O (l) C6H12O6 (s)+ 6O2 (g)

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Calculate the volume of carbon dioxide, adjusted to 25 ºC and 1.0 atm , that plants need to make 1.00 g of glucose.

6CO2 (g) + 6H2O (l) C6H12O6 (s)+ 6O2 (g)


What did we learn today?

IDEAL GAS LAW and IDEAL GAS EQUATION

CONCEPT OF NUMBER DENSITY vs MASS DENSITY

DERIVED EQUATION FOR RELATIONSHIP BETWEEN MASS DENSITY AND THE MOLAR MASS OF A GAS

Anything Else? Please Share….

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DAY 3 LEARNING OUTCOMES

Perform calculations using the ideal gas equation

Explain the relationship between the number density and the mass density for a given gas

Use the ideal gas law to determine MW of a gas

Apply the concept of the gas laws to gas phase reactionsand perform stoichiometric calculations

Using the gas properties, masses, moles, limiting reagents and percent yields

Unit1Day3-LaBrake

vanden bout/labrake/crawford ch301 gas laws - day 3

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