Transcript Week 33 Chemistry

Week 33 Chemistry
Gas Laws
Warm Up: 4 Minutes
Stay in your own seat
Write the Learning
Target
You should be working SILENTLY
If the pressure of a tire is over 35 psi, it is likely to
explode. If the initial pressure of a tire is 32.5 psi at
15 ºC, calculate the new pressure at 40 ºC.
Is the tire likely to explode at 40 ºC?
24
183
This is the passing rate
How to improve your grade
Turn in missing assignments (this is the biggest
issue right now)
Make up Missed Exams
Come to tutorials for extra help
Agenda
Warm Up: 7 Minutes
Combined Gas Law Video: 15 Minutes
Guided Practice: 13 Minutes
Independent Practice: 15 Minutes
Closing: 3 Minutes
Combined Gas Law Video
1. Go to shschem.weebly.com (our class website)
Bookmark this if you haven’t done so already!!!
2. Hover over my page:
Mr. Ghosh  Video Lessons
3. Watch video for April 28
4. Take notes on your handout
Let’s Review our Gas Laws
P1 P2

T1 T2
G. Lussac’s Law
P1V1 = P2V2
Boyle’s Law
V1 V2

T1 T2
Charles Law
Putting them all together…
P1 V1 P2 V2
=
n1 T1 n2 T2
# of Moles
This is the
Combined Gas Law
Problem Solving Tip
Begin all problems using the Combined Gas Law
If any variables (P, V, n, or T) are not present,
delete them from both sides of the equation
Substitute and solve using remaining values
Example: Problem has Pressure and Temperature,
but no Volume or Moles
Example 1
The initial pressure, temperature, and volume of a car tire are 33
psi, 25 ºC, and 4.8 L. If the temperature outside rises to 35 ºC
and the volume expands to 5.0 L, what is the new pressure
inside the tire?
Example 2
3.2 moles of gas have a volume of 800.0 mL at -23 ºC. How
many moles of gas would be present in 675.0 mL at 227.0 ºC?
Guided Practice
Take 13 seconds to study the problem.
When Mr. Ghosh indicates that you can talk,
take 48 seconds to work the problem with your
teammates.
When Mr. Ghosh says SWAG, be ready to share
and explain your answers.
Guided Practice #1
A toy balloon contains 3 moles of gas at an internal pressure of
1.05 atm and a volume of 5.0 L. If the initial temperature of the
balloon is 20 ºC, what will the volume of the balloon be if it rises
to an altitude where the pressure is 0.65 atm and the
temperature is -15 ºC?
7.11 L
Guided Practice #2
A small research submarine contains gas with a volume of
1.2 x 105 L at a pressure of 1.0 atm and a temperature of
15 ºC. Assuming the number of moles remains constant,
the submarine descends to a depth where the new
volume is 767 L and the temperature is 3 ºC. What is the
new pressure on the gas?
150 atm
Guided Practice #3
If I initially have 4.0 L of a gas at a temperature of 38 ºC,
what will the temperature be if I increase the volume to
5.0 L?
389 K
Independent Practice
Its time to see if you truly understand
the Combined Gas Law. ..
Closing
Which law relates P and V?
Which law relates V and T?
Which law relates P and T?
Which law relates P, V, n, and T?
Warm Up: 4 Minutes
Stay in your own seat
Write the Learning
Target
You should be working SILENTLY
The initial pressure, volume, and temperature a gas are 1 atm,
3.4 L, and 27 ºC. If the pressure increases to 3.2 atm, and the
temperature rises to 79 ºC, what is the new volume?
The initial pressure, volume, and temperature a gas are 1
atm, 3.4 L, and 27 ºC. If the pressure increases to 3.2 atm,
and the temperature rises to 79 ºC, what is the new
volume?
Agenda
Warm Up: 7 Minutes
Ideal Gas Law Video: 15 Minutes
Guided Practice: 13 Minutes
Independent Practice: 15 Minutes
Closing: 3 Minutes
Ideal Gas Law Video
1. Go to shschem.weebly.com (our class website)
Bookmark this if you haven’t done so already!!!
2. Hover over my page:
Mr. Ghosh  Video Lessons
3. Watch video for April 29
4. Take notes on your handout
Ideal Gas
Perfect gases under perfect
conditions
IDEAL GAS LAW
DESCRIBING THE BEHAVIOR OF IDEAL GASES
PV = nRT
P = pressure
V = volume in LITERS
n = moles
R = gas constant
T = temperature in KELVIN
L atm
0.08206
m ol K
8.314
62.4
L mmHg
mol K
L kPa
mol K
Example 1
What is the volume of 0.25 moles of
oxygen gas at 250 K and 360 mmHg?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Example 2
How many moles of hydrogen would
be contained in 6.0 L of the gas at
101.4 kPa and 64oC?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Guided Practice #1
What is the temperature of 0.456 mol
of gas at 1 atm if the gas is held in a
10.0 L container?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Guided Practice #2
What volume is occupied by 1.23
moles of methane, CH4, at 27oC and
1.59 atm?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Independent Practice
Its time to see if you truly understand
the Ideal Gas Law. ..
Closing
What variables are needed to use the
Ideal Gas Law equation?
Warm Up: 3 Minutes
Stay in your own seat
Write the Learning
Target
You should be working SILENTLY
The pressure for an ideal gas is 72.8 kPa. If
there are 4.6 moles in a 10.7 L container,
calculate the temperature of the gas.
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Agenda
Warm Up: 7 Minutes
Ideal Gas Law Video: 15 Minutes
Guided Practice: 13 Minutes
Independent Practice: 15 Minutes
Closing: 3 Minutes
Announcements
Gas Law Quiz  FRIDAY (Boyles, Charles, G. Lussac’s,
Combined, Ideal)
Gas Law Exam  5/7
Today you will need:
Calculator
Periodic Table
Ideal Gas Law-Part 2 Video
1. Go to shschem.weebly.com (our class website)
Bookmark this if you haven’t done so already!!!
2. Hover over my page:
Mr. Ghosh  Video Lessons
3. Watch video for April 30
4. Take notes on your handout
Example 1
What is the volume of 22.0 g carbon
dioxide (CO2) at 312 K and 795
mmHg?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Uh oh…
We are given grams…but “n” needs to be in moles.
How do we go from grams to moles?
Use Molar Mass!
Review of Molar Mass
Example 1
What is the volume of 22.0 g carbon
dioxide (CO2) at 312 K and 795
mmHg?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Example 2
How many grams of hydrogen gas
(H2) would be contained in 5.35 L of
the gas at 119.7 kPa and -29oC?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Guided Practice #1
What is the temperature of 71.8 g
nitrogen gas (N2) at 1 atm if the gas is
held in a 10.0 L container?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Guided Practice #2
What volume is occupied by 7.02
moles of sulfur dioxide, SO2, at 361oC
and 14.07 atm?
8.314
62.4
L kPa
m ol K
L mmHg
mol K
L atm
0.08206
m ol K
Independent Practice
Its time to see if you truly understand
the Ideal Gas Law. ..
Closing
How does the ideal gas law relate P, V,
n, and T?
Warm Up: 4 Minutes
Stay in your own seat
Write the Learning
Target
You should be working SILENTLY
An ideal gas is trapped in a closed container. The pressure
inside the container is 634 mmHg. If there are 38 g H2 at 98 ºC,
calculate the volume of the container.
Agenda
Warm Up: 7 Minutes
Gas Law Stoichiometry Video: 15 Minutes
Guided Practice: 13 Minutes
Independent Practice: 15 Minutes
Closing: 3 Minutes
Gas Law Stoichiometry Video
1. Go to shschem.weebly.com (our class website)
Bookmark this if you haven’t done so already!!!
2. Hover over my page:
Mr. Ghosh  Video Lessons
3. Watch video for May 1
4. Take notes on your handout
Remember this?
It’s time to do…
Example 1
The reaction of zinc and hydrochloric acid is shown below:
Zn + 2 HCl  ZnCl2 + H2
If 17L of hydrogen gas are formed at a pressure of 2.6 atm and
a temperature of 180 ºC, how many moles of zinc reacted?
Example 2
How many grams of Mercury (II) Chloride will react with 0.567 L
ammonia at 27.0 ºC and 115 kPa?
HgCl2 + 2 NH3  NH4Cl + Hg(NH2)Cl
Guided Practice #1
The combustion of octane is shown below:
2 C8H18 + 25 O2  16 CO2 + 18 H2O
If 38L of carbon dioxide are formed at a pressure of 186 mmHg
and a temperature of 146 K, how many moles of octane
reacted?
Guided Practice #2
How many grams of sodium hydrogen carbonate (NaHCO3) are
needed to react to form 11.64 liters of carbon dioxide?
HNO3 + NaHCO3  NaNO3 + CO2 + H2O
Independent Practice
Its time to see if you truly understand
Gas Law Stoichiometry. ..
Closing
How does the ideal gas law relate P, V,
n, and T?
Warm Up: 5 Minutes
Stay in your own seat
You should be working SILENTLY
Write the Learning
Target
Zinc metal reacts with hydrochloric acid according to the reaction below:
Zn + 2 HCl  2 ZnCl2 + H2
If 14.5 L hydrogen gas were produced at a pressure of 4.7 atm and a
temperature of 45 ºC, calculate the number of moles of hydrochloric acid
that reacted. [Use R = 0.08206]
Agenda
Warm Up: 9 Minutes
Quiz Expectations: 4 Minutes
Gas Laws Quiz: 30 Minutes
Closing: 2 Minutes
Material Covered
Boyle’s Law
Charles Law
G. Lussac’s Law
Combined Gas Law
Ideal Gas Law
Gas Law Stoichiometry (Extra Credit)
Goal
 To demonstrate mastery, we are shooting for
Check Point
What is your goal for this quiz?
Expectations for Quiz
Clear your desk of everything except a....
1. Pencil/Pen
2. Calculator
All backpacks and binders on the
floor
Expectations
Students will keep eyes on own paper
Cheating will result in an automatic ZERO
Students will remain SILENT for the
duration of the quiz
Good Luck!!
Quiz Correction:
For the Extra Credit problem:
Assume P = 1 atm and T = 0 ºC
Closing
How was your Quiz Today?
What topics do you feel you still need
review on?