Difference between revisions of "Ch5 Lec 2"

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in progress...
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Greetings,
 +
:If you look on the webpage, you will see that there is an active link to the Exam 2 on Friday April 3. I suggest you have a look at that link to give you more information about the format of the exam.
 +
 
 +
Note that the chapter 5 outline was given in Lecture 1. I have chosen to focus our attention on only the first 4 sections of chapter 5.
 +
 
 +
The following two sections are both discussed in the following Crash Course...please note that these crash course videos provide a huge amount of information in a short time period. This one in particular goes into a lot of the background histroy, which is an important thing to know, but will not be on the exam...have a look at:
 +
:[https://youtu.be/BxUS1K7xu30 The Ideal Gas Law: Crash Course Chemistry #12]
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===Gas laws (Sec 5.3)===
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READ this section...
 +
 
 +
Summary:
 +
:[[File:Screen Shot 2020-03-29 at 11.08.15 AM.png|400px|thumb|center|from Crash Course video]]
 +
 
 +
====Boyle's Law Question====
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:So if you have a container of gas at 1.0 atm pressure (P<sub>1</sub>) and 1.0 L volume (V<sub>1</sub>)...if the volume is changed to 0.5 L (P<sub>2</sub>), then what happens to the pressure?
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::Use: P<sub>1</sub>V<sub>1</sub>=P<sub>2</sub>V<sub>2</sub>;
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<div align="right"> Answer: 2.0 atm </div>
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====Charles' Law Question 1====
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:So if you have a balloon of gas at a temperature of 298 K (T<sub>1</sub>) and 1.0 L volume (V<sub>1</sub>)...if the temperature is changed to 330 K (T<sub>2</sub>) what is the new volume?
 +
::Use: V<sub>1</sub>/T<sub>1</sub>=V<sub>2</sub>/T<sub>2</sub>;
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<div align="right"> Answer: 1.11 L </div>
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====Charles' Law Question 2====
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:In Charles Law Question 1, we were dealing with a balloon; a balloon has movable walls and hence the volume can change. If you do the same experiment in a jar (non movable walls) then the pressure will change.
 +
:So if you have a 1.0 L jar of gas at a temperature of 298 K (T<sub>1</sub>) and a pressure of 1.0 atm (P<sub>1</sub>)...if the temperature is changed to 330 K (T<sub>2</sub>) what is the new pressure?
 +
::Use: P<sub>1</sub>/T<sub>1</sub>=P<sub>2</sub>/T<sub>2</sub>;
 +
 
 +
<div align="right"> Answer: 1.11 atm </div>
 +
 
 +
====Avogadro's Law Question 1====
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:If you have 1.0 moles (n<sub>1</sub>) of gas and in a balloon with a volume of 22.4 L (V<sub>1</sub>), what is the volume of the balloon once 0.25 moles (n<sub>2</sub>) of gas is released?
 +
::Use: V<sub>1</sub>/n<sub>1</sub>=V<sub>2</sub>/n<sub>2</sub>;
 +
 
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<div align="right"> Answer: 16.8 L </div>
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 +
'''''There is a WebAssign available now (Monday, 8 am) for you to practice gas law questions...'''''

Latest revision as of 03:02, 30 March 2020

Greetings,

If you look on the webpage, you will see that there is an active link to the Exam 2 on Friday April 3. I suggest you have a look at that link to give you more information about the format of the exam.

Note that the chapter 5 outline was given in Lecture 1. I have chosen to focus our attention on only the first 4 sections of chapter 5.

The following two sections are both discussed in the following Crash Course...please note that these crash course videos provide a huge amount of information in a short time period. This one in particular goes into a lot of the background histroy, which is an important thing to know, but will not be on the exam...have a look at:

The Ideal Gas Law: Crash Course Chemistry #12

Gas laws (Sec 5.3)

READ this section...

Summary:

from Crash Course video

Boyle's Law Question

So if you have a container of gas at 1.0 atm pressure (P1) and 1.0 L volume (V1)...if the volume is changed to 0.5 L (P2), then what happens to the pressure?
Use: P1V1=P2V2;
Answer: 2.0 atm

Charles' Law Question 1

So if you have a balloon of gas at a temperature of 298 K (T1) and 1.0 L volume (V1)...if the temperature is changed to 330 K (T2) what is the new volume?
Use: V1/T1=V2/T2;
Answer: 1.11 L

Charles' Law Question 2

In Charles Law Question 1, we were dealing with a balloon; a balloon has movable walls and hence the volume can change. If you do the same experiment in a jar (non movable walls) then the pressure will change.
So if you have a 1.0 L jar of gas at a temperature of 298 K (T1) and a pressure of 1.0 atm (P1)...if the temperature is changed to 330 K (T2) what is the new pressure?
Use: P1/T1=P2/T2;
Answer: 1.11 atm

Avogadro's Law Question 1

If you have 1.0 moles (n1) of gas and in a balloon with a volume of 22.4 L (V1), what is the volume of the balloon once 0.25 moles (n2) of gas is released?
Use: V1/n1=V2/n2;
Answer: 16.8 L

There is a WebAssign available now (Monday, 8 am) for you to practice gas law questions...