Week 33 Chemistry Gas Laws

Warm Up: 4 Minutes You should be working SILENTLY Stay in your own seat 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? Write the Learning Target

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 P 1 V 1 = P 2 V 2 G. Lussac’s LawBoyle’s LawCharles Law

Putting them all together… This is the Combined Gas Law # of Moles

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 moles of gas have a volume of mL at -23 ºC. How many moles of gas would be present in mL at 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 10 5 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 You should be working SILENTLY Stay in your own seat 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? Write the Learning Target

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

Example 1 What is the volume of 0.25 moles of oxygen gas at 250 K and 360 mmHg?

Example 2 How many moles of hydrogen would be contained in 6.0 L of the gas at kPa and 64 o C?

Guided Practice #1 What is the temperature of mol of gas at 1 atm if the gas is held in a 10.0 L container?

Guided Practice #2 What volume is occupied by 1.23 moles of methane, CH 4, at 27 o C and 1.59 atm?

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 You should be working SILENTLY Stay in your own seat 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. Write the Learning Target

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 (CO 2 ) at 312 K and 795 mmHg?

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 (CO 2 ) at 312 K and 795 mmHg?

Example 2 How many grams of hydrogen gas (H 2 ) would be contained in 5.35 L of the gas at kPa and -29 o C?

Guided Practice #1 What is the temperature of 71.8 g nitrogen gas (N 2 ) at 1 atm if the gas is held in a 10.0 L container?

Guided Practice #2 What volume is occupied by 7.02 moles of sulfur dioxide, SO 2, at 361 o C and atm?

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 You should be working SILENTLY Stay in your own seat An ideal gas is trapped in a closed container. The pressure inside the container is 634 mmHg. If there are 38 g H 2 at 98 ºC, calculate the volume of the container. Write the Learning Target

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  ZnCl 2 + H 2 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 L ammonia at 27.0 ºC and 115 kPa? HgCl NH 3  NH 4 Cl + Hg(NH 2 )Cl

Guided Practice #1 The combustion of octane is shown below: 2 C 8 H O 2  16 CO H 2 O 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 (NaHCO 3 ) are needed to react to form liters of carbon dioxide? HNO 3 + NaHCO 3  NaNO 3 + CO 2 + H 2 O

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 You should be working SILENTLY Stay in your own seat Zinc metal reacts with hydrochloric acid according to the reaction below: Zn + 2 HCl  2 ZnCl 2 + H 2 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 = ] Write the Learning Target

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 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?