Physical Science 2-4: Properties of Gases

​Physical Science 2-4: Properties of Gases

Multiple Choice

What is a physical property of these strawberries?

• Red

• Rotten

• Flammable

Multiple Choice

What is a chemical property of paper?

• Flammable

• White

• Light

Multiple Choice

Is an ice cream cone melting a physical or chemical change?

• Physical

• Chemical

Multiple Choice

Is toasting bread a physical or chemical change?

• Physical

• Chemical

Multiple Choice

The ability to rust is a

• Physical property

• Chemical property

Multiple Choice

The element iron is very magnetic. This is an example of a

• Physical property

• chemical property

Lesson Objectives

• Describe factors that affect how a gas behaves

• Use Boyle's law to predict the behavior of a gas

• Use Charles's law to predict the behavior of a gas

Introduction to Gases

• The properties of different states depend on how the particles move in that state of matter

• Gas particles move quickly and spread out to fill the volume of the container

• How much space a gas takes up is dependent on three factors

  • temperature

  • volume

  • pressure

Temperature

• Temperature: Measures the amount of kinetic energy in a substance

  • Tells you how fast the particles are moving

  • We can feel temperature as heat, but heat is not what is being measured

• As the temperature increases, the amount of energy the particles have increases, and they move faster and spread out

• As the temperature decreases, the amount of energy the particles have decreases, and they move more slowly and stay closer together

Volume

• Because gas particles do not stick together, they are able to spread out and take up more space

• The Volume of a gas is dependent on the size of the container it is in

  • If you have a rigid container, the gas particles will be pushed closer together

  • If you have a flexible container, it will expand with the gas

Pressure

• Pressure: The amount of force that is put on an area

• When particles are close together, they exert pressure on the particles around them

  • If you have more particles, they exert more pressure

  • If you have particles moving with more energy, they exert more pressure

What are the Gas Laws?

• When you have a gas, the temperature, pressure, and volume are all related to one another and affect each other.

• Gas Laws are a set of equations that help to describe the relationships between the different variables that affect a gas

• In this class, we will look at two of the gas laws

  • Boyle's Law

  • Charles's Law

Boyle's Law

• Boyle's Law: The Volume of a gas is inversely proportional to the pressure of the gas when the temperature is constant

  • As the pressure increases, the volume decreases

Boyle's Law Sample Problem 1

• A gas that originally occupies 22.4 liters has its pressure increased from 760 mmHg to 1520 mmHg. What is the new volume?

  • Step 1: Identify your Variables

    • P₁₌

    • V₁=

    • P₂=

    • V₂=

  • Step 2: Plug your Variables into the Boyle's Law Equation

Boyle's Law Sample Problem 1

• A gas that originally occupies 22.4 liters has its pressure increased from 760 mmHg to 1520 mmHg. What is the new volume?

  • Step 1: Identify your Variables

    • P₁₌760

    • V₁= 22.4

    • P₂=1520

    • V₂=?

  • Step 2: Plug your Variables into the Boyle's Law Equation and solve for your unknown

Fill in the Blank

A gas that originally occupies 22.4 liters has its pressure increased from 760 mmHg to 1520 mmHg. What is the new volume? Round to one Decimal Place

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Boyle's Law Sample Problem 2

• A weather balloon contains 59.5 L of helium at sea level, where the pressure is 101.3 kPa. The balloon is released from a mountaintop where the pressure is 61.7 kPa. What is the volume of the balloon when it is released?

  • Step 1: Identify your Variables

    • P₁=

    • V₁=

    • P₂=

    • V₂=

  • Step 2: Plug your Variables into the Boyle's Law Equation

Boyle's Law Sample Problem 2

• A weather balloon contains 59.5 L of helium at sea level, where the pressure is 101.3 kPa. The balloon is released from a mountaintop where the pressure is 61.7 kPa. What is the new volume of the balloon when it is released?

  • Step 1: Identify your Variables 

    • P₁= 101.3

    • V₁=59.5

    • P₂= 61.7

    • V₂=?

  • Step 2: Plug your Variables into the Boyle's Law Equation and Solve

Fill in the Blank

A weather balloon contains 59.5 L of helium at sea level, where the pressure is 101.3 kPa. The balloon is released from a mountaintop where the pressure is 61.7 kPa. What is the new volume of the balloon when it is released? Round to Two Decimal Places

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Boyle's Law Sample Problem 3

• What pressure will be needed to reduce the volume of 77.4 L of helium at 98.0 kPa to a volume of 60.0 L?

  • Step 1: Identify your Variables

    • P₁=

    • V₁=

    • P₂=

    • V₂=

  • Step 2: Plug your Variables into the Boyle's Law Equation

Boyle's Law Sample Problem 3

• What pressure will be needed to reduce the volume of 77.4 L of helium at 98.0 kPa to a volume of 60.0 L?

  • Step 1: Identify your Variables

    • P₁= 98.0

    • V₁= 77.4

    • P₂= ?

    • V₂=60.0

  • Step 2: Plug your Variables into the Boyle's Law Equation

Fill in the Blank

What pressure will be needed to reduce the volume of 77.4 L of helium at 98.0 kPa to a volume of 60.0 L? Round your answer to two decimal Places.

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Multiple Choice

What is the formula for Boyle's Law?

• P₁V₁=P₂V₂
• P₁V₁/P₂V₂
• P₁V₂=P₂V₁
• P₁/V₁=P₂/V₂

Fill in the Blank

You have a gas that has a pressure of 2 ATM and a volume of 10L.  What would be the new volume if the pressure was changed to 1 ATM?

Fill in the Blank

A gas at a volume of 4 liters is at a pressure of 2 atm. The volume is changed to 16 Liters, what must the new pressure be?

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Charles's Law

• Charles's Law: the volume of a gas is directly proportional to the temperature of a gas when the pressure is constant

  • As you increase the temperature of a gas, the Volume will increase

Charles's Law Sample Problem 1

• A weather balloon contains 5.30 kL of helium gas when the temperature is 285 Kelvin. At what temperature will the balloon’s volume have increased to 6.00 kL?

  • Step 1: Identify your Variables

    • V₁=

    • T₁=

    • V₂=

    • T₂=

  • Step 2: Plug your Variables into Charles' Law Equation

Charles's Law Sample Problem 1

• A weather balloon contains 5.30 kL of helium gas when the temperature is 285 Kelvin. At what temperature will the balloon’s volume have increased to 6.00 kL?

  • Step 1: Identify your Variables

    • V₁= 5.30

    • T₁= 285

    • V₂= 6.00

    • T₂= ?

  • Step 2: Plug your Variables into Charles' Law Equation

Fill in the Blank

A weather balloon contains 5.30 kL of helium gas when the temperature is 285 Kelvin. At what temperature will the balloon’s volume have increased to 6.00 kL? Round Your Answer to Two Decimal Places

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Charles's Law Sample Problem 2

• A balloon is inflated with 6.22 L of helium at a temperature of 309 Kelvin. What is the volume of the balloon when the temperature is 295 Kelvin?

  • Step 1: Identify your Variables

    • V₁=

    • T₁=

    • V₂=

    • T₂=

  • Step 2: Plug your Variables into Charles' Law Equation

Charles's Law Sample Problem 2

• A balloon is inflated with 6.22 L of helium at a temperature of 309 Kelvin. What is the volume of the balloon when the temperature is 295 Kelvin?

  • Step 1: Identify your Variables

    • V₁= 6.22

    • T₁= 309

    • V₂= ?

    • T₂= 295

  • Step 2: Plug your Variables into Charles' Law Equation

Fill in the Blank

A balloon is inflated with 6.22 L of helium at a temperature of 309 Kelvin. What is the volume of the balloon when the temperature is 295 Kelvin? Round your Answer to Two Decimal Places.

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Charles's Law Sample Problem 3

• A balloon has a volume of 10.50 L if the temperature is 288 Kelvin. If the temperature is 238 Kelvin, what will be the volume of the balloon?

  • Step 1: Identify your Variables

    • V₁=

    • T₁=

    • V₂=

    • T₂=

  • Step 2: Plug your Variables into Charles' Law Equation

Charles's Law Sample Problem 3

• A balloon has a volume of 10.50 L if the temperature is 288 Kelvin. If the temperature is 238 Kelvin, what will be the volume of the balloon?

  • Step 1: Identify your Variables

    • V₁= 10.50

    • T₁= 288

    • V₂= ?

    • T₂= 238

  • Step 2: Plug your Variables into Charles' Law Equation

Fill in the Blank

A balloon has a volume of 10.50 L if the temperature is 288 Kelvin. If the temperature is 238 Kelvin, what will be the volume of the balloon? Round Your Answer two Two Decimal Places

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Multiple Choice

What is the formula Charles' Law?

• V = T
• VT = VT
• T₁ / V_{1 =} T₂ / V₂
• V₁ / T₁ = V₂ / T₂

Fill in the Blank

(Charles Law) There are 65 liters of helium in a balloon at 35 K. If the temperature of the balloon is increased to 40 K, what will the new volume of the balloon be? Round Your Answer to one Decimal Place!

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Fill in the Blank

There are 40 liters of helium in a balloon at 100 K. If the temperature of the balloon is increased to 200 K, what will the new volume of the balloon be? Round Your Answer to a Whole Number!