AIR PRESSURE. What is pressure? A force that is applied over an area.

Slides:

Advertisements

Similar presentations

The GAS LAWS Gases have mass Gases diffuse Gases expand to fill containers Gases exert pressure Gases are compressible Pressure & temperature are dependent.

Advertisements

Gases Properties of Gases Gas Pressure The Nature of Gases Gases are compressible Why can you put more air in a tire, but can’t add more water to a glass.

What is Pressure? P= Force/area Pressure units are N/m 2 or Pascal(Pa)

Gas Pressure. Let’s start with straws…. Both the red and blue arrows represent the same thing—the pressure we feel from the atmosphere What do you notice.

Chapter 11: Behavior of Gases

Pressure Image Source: MSWord Clipart. 4 Main Things You Can Measure About a Gas… Pressure (Pascals) Volume (Liters) Amount (moles) Temperature (Kelvins)

© 2013 Pearson Education, Inc. Chapter 7, Section 2 General, Organic, and Biological Chemistry Fourth Edition Karen Timberlake 7.2 Gas Pressure Chapter.

Measuring Gases College Chemistry.

Existence of Gas pressure based on the kinetic theory gas molecules move freely and randomly. The gas molecules collide with one another and also collide.

AIR PRESSURE Keeping an Atmosphere Atmosphere is kept by the world’s gravity –Low mass (small) worlds= low gravity =almost no atm. –High mass (large)

PRESSURE CHEMISTRY MODELING PRESSURE MACRO- SCALE Pressure is the amount of force exerted over a given area The force exerted is caused by particles.

Pressure. The amount of force an object puts on a surface. Pressure is measured by a barometer. Atmospheric pressure comes from air being pulled down.

Gasses Kinetic molecular theory Pressure. Introduction Earth’s atmosphere is a gaseous solution composed of mostly nitrogen and oxygen The atmosphere.

Section 13.1 Describing the Properties of Gases 1.To learn about atmospheric pressure and how barometers work 2.To learn the units of pressure 3.To understand.

What is Gas Pressure? What are the factors influencing Pressure? Gas Pressure Volume Temperature How do we measure each?

Pressure. Remember, Gas Volume Changes…  Suppose you have a one liter bottle of air. How much air do you actually have?  A liter of air means little.

Ch 11 Gases Gases and Pressure 11.1 Pressure and Force Pressure – (P) the force per unit area on a surface Pressure – (P) the force per unit area on.

1.7.Pressure GCSE Physics David Raju Vundi.

1 Gases Chapter Properties of Gases Expand to completely fill their container Take the Shape of their container Low Density –much less than solid.

Gas Laws Units Used With Gas Laws PRESSURE: The force applied by many gas particles colliding with each other. 1.Atmospheres (atm) STP= 1atm 2.Pounds.

GAS LAWS. Properties of Gases  Composed of randomly scattered particles  No definite _________ or ___________  Spread out to fill the space of their.

 States of Matter  Solid  Particles close together  May only vibrate  Liquid  Particles not as close together  Particles may move past each other,

The Properties of Gases. Properties of Gases 1. Gases expand to fill the container. 2. Gases take on the shape of the container. 3. Gases are highly compressible.

Gas Laws Units Used With Gas Laws PRESSURE: The force applied by many gas particles colliding with each other. 1.Atmospheres (atm) STP= 1atm 2.Pounds.

Pressure and Temperature William Thomson “Lord Kelvin”

1 Gases: Ch Pressure Basic properties of gases –Expand to completely fill their container –Take the shape of their container –Have low density (compared.

Chapter 12: States Of Matter

Gas Laws Boyle ’ s Law Charles ’ s law Gay-Lussac ’ s Law Avogadro ’ s Law Dalton ’ s Law Henry ’ s Law 1.

Section 10-2: Pressure Pressure (P): the force per unit area on a surface Pressure = Force / Area Newton (N): SI unit of force.

AIR PRESSURE Keeping an Atmosphere Atmosphere is kept by the world’s gravity –Low mass (small) worlds= low gravity =almost no atm. –High mass (large)

States of Matter. The Kinetic-Molecular Theory Explains the properties of gases, liquids, and solids.

Measuring Pressure.

Chapter 13 Notes Kinetic Molecular Theory. Kinetic Theory and Gases Kinetic Energy—Energy that an object has due to motion. The Kinetic Theory states:

13.1 Describing the Properties of Gases

Properties of Gases Gas Pressure.

Fluids & Pressure Objectives:

Gases consist of large numbers of tiny particles that are far apart relative to their size. Collisions between gas particles and between particles and.

15.2 Air Pressure Key Concepts: What are some of the properties of air? What instruments are used to measure air pressure? How does increasing altitude.

Pressure in solids, liquids Atmospheric pressure

Gases and Pressure Section Vocabulary Pressure: the force per unit area on a surface Atmospheric pressure: the force per unit area exerted against.

Palm trees feeling the push of the air from a hurricane wind A balloon is inflated from a CO2 canister; pressure is increasing as the balloon inflates.

The pressure acting on the bottom of the suspended metal block is greater than that acting on the top due to the increase of pressure with depth. 

Weather Part 2: Air Pressure. Air Pressure… is a measure of the force of the air pressing down on Earth’s surface. at any point on the Earth is equal.

Gas Laws! Introduction to Gas Laws.. Key Terms  Pressure: the amount of force per unit area of surface  Newton: the SI unit for force  Pascal: the.

Pressure Force applied per unit area. Force Area.

Pressure Pressure- force applied to one unit of surface area Pressure = force / area Metric force unit = newton (N) Metric pressure unit = pascals (Pa)

Air Pressure Notes. Properties of Air Oxygen (O 2 ) Nitrogen (N 2 ) CO 2, H 2 O, and others.

Chapter 5: Gases CHE 123: General Chemistry I Dr. Jerome Williams, Ph.D. Saint Leo University.

Gas Pressure.  When you complete this presentation, you will be able to:  describe gas pressure in terms of the motion of gas particles.  describe.

Introduction to Gas Laws Chapter 14 Benchmark 4. Pressure The force per unit area that the particles in the gas exert on the walls of their container.

Gas Notes. Physical Properties of all gases  Gases have mass  Gases are easily compressed –Air in you car tires, air in a basketball  Gases will expand.

The air is made up of molecules. Air molecules are everywhere.

The weight of Earth’s atmosphere above us exerts a pressure on us. In a way, we live at the bottom of an ocean of air.

Behavior of GASES.

Lecture Presentation Chapter 8 Gases Karen C. Timberlake.

Add to table of Contents

Pressure and Temperature

Gases & Atmospheric Chemistry

The Nature of Gases Gases have some interesting characteristics that have fascinated scientists for 300 years. The first gas to be studied was air &

What is Pressure? To create the most pressure,

Gases Boyle’s Law.

The Nature of Gases Under Pressure!

Northwestern High School

Chapter 11 Pressure and Force

Gases: Critical to Our Lives

Chapter 11 Gases and Pressure Section 1.

Presentation transcript:

AIR PRESSURE

What is pressure? A force that is applied over an area.

What is air pressure? Balloon example – what about the particles is causing pressure in the balloon? Air pressure is caused by the particles of air colliding with sides of the container (in this case, the balloon)

What is atmospheric pressure? What is the Earth’s atmosphere made up of? Why does Earth have an atmosphere?

Gravity and Atmospheric Pressure The stronger the gravity, the more gas is held by the world and the greater the weight of atmospheric pressure on a point.

Atmospheric Pressure Atmospheric pressure – the amount of force (gravity) exerted on 1 meter 2 column of air.

High altitudes = lower pressure Low altitudes = higher pressure

What would be the units of pressure? Pressure is a force that is exerted on an area. Units of Pressure: – Atmosphere (atm.) – pounds per square inch or psi (1 atm. = 14.7 pounds per square inch) – mm or inches of mercury (1 atm.= 760 mm or inches of Hg) – torrs (1 torr = the pressure exerted by 1 cm of mercury) – Pascal or Pa(1 newton per square meter) 1 kPa = 1000 Pa and 1 atm. = kPa

What happens when you draw a liquid through a straw into your mouth? When you suck on a straw, you remove some of the particles of air in the straw. Since there are more particles of air striking the liquid in the cup than are striking the liquid in the straw, the effect of these extra collisions is to push the liquid up into your mouth. So actually, you are not sucking the liquid into your mouth, the atmosphere is pushing it there.

Evangelista Torricelli ( ) Torricelli wanted to figure out why he could not pump liquid up to the top floor of his villa with a pump. He reasoned that even if the pump could remove all the air above the column of liquid, the pressure exerted by the atmosphere could only support a column of liquid so high (~34 ft). As the story goes, he replaced the top portion of the pipe with a glass tube and noted that the water level fluctuated depending on the weather. He found that he could more conveniently study this behavior if he used a liquid with a greater density. He filled the tube with mercury (d = 13.6 g/mL) and found that atmosphere could pressure could support a column of mercury varying from inches. Such a device is called a barometer.

Torricelli’s barometer used a glass column suspended in a bowl of mercury. The pressure of the air molecules pushed the mercury up into the glass tube. The weight of the mercury in the tube was equal to the weight of the air pressing down on the mercury in the dish.

As atmospheric pressure increases… The mercury in the tube rises.

Another Instrument used to measure pressure… Manometer

Manometers Cont.