Welcome

Please register to have access to more features!

It is highly recommended that you have Javascript enabled; many features will not work unless you do. The recommended browsers are Firefox and Chrome; the board is also NOT mobile-friendly.

Please invite your friends!

If you were referred by someone (ex. me, Jessica) please put their username in the referral box on the registration page. Ask them if you don't know their username.

If you are visiting for TESTING PURPOSES ONLY, this is the test account information:


Username:
Test
Password: test123



Select a forum to post in:

Gas Laws

Science topics

Moderators: Jessica, Teachers

Looking for a topic?
View the Science Topics Directory to find topics quicker under different kinds of science.

Gas Laws

Post Number: #1  Postby Jessica » May 28th, 2011, 8:15 pm

Gas Pressures


Air is a mixture of several gases and the gaseous molecules are in constant motion. This constant motion causes them to collide with objects and exert a pressure. This pressure is known as atmospheric pressure.

As the particles of gas decrease, the collisions are not as frequent, and pressure decreases.

Pressure is the measure of force per unit area.

  • SI unit for pressure is the kPa.
  • Two other units are still commonly used:
    • millimeters of mercury
    • atmospheres

1 atm = 760 mm Hg = 760 torr = 101.3 kPa = 14.7 psi





Laws


Boyle's Law

At constant temperature and number of moles, the pressure and volume of a gas are INVERSELY related. In other words, as pressure is reduced, the volume increases. And vice versa - if pressure is increased, volume decreases.


Charles' Law

At constant pressure and number of moles, the temperature (in Kelvin --> K = Celsius + 273) and volume of a gas are DIRECTLY related. In other words, if temperature is increased, so will the volume. If it decreases, so does the volume.


Combined Gas Laws






Ideal Gas Equation


An ideal gas is one in which the molecules have no volume and exert no attraction for one another. No ideal gases exist, but under certain conditions of temperature and pressure, real gases approach ideal behavior.

The four variables used to describe the state of a gas can be combined into a single expression.

PV = nRT


where R is a proportionality constant known as the ideal gas constant.
  • 0

User avatar
Jessica
Board Owner
Topic Author

Founder
Sapphire
Sapphire
 
15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership15 years of membership
 
Posts: 3,505
Topics: 1,244
Articles: 30
Joined: December 22nd, 2010, 8:04 pm
Local time: April 20th, 2026, 8:19 am
Last Visit: February 23rd, 2026, 9:06 pm
Location: Pennsylvania
Gender: Female
Cash on hand: 6,565.41
Bank: 160,501.08
Reputation: 148
Medals: 21
#1: July 2012 1st Place (1) R-Contest #1 First Place (1) Best staff member 2013 (1) Easter Egg Hunt 2013 (1) Graphic Drawing Participant (1) 1 Year (1) 2 Years (1) 3 Years (1) 4 Years (1) 5 Years (1)
6 Years (1) 7 Years (1) 8 Years (1) 9 Years (1) Founder (1) Highest Rep (1) Referrer (1) Top poster (1) Facebook group (1) Pin-Board (1)
Article Author (1)
Referrals: 27
Blog: View Blog (536)
Subject(s): Chinese, Math
Global Moderator
Admin
Moderator

Return to Science Topics

Login  •  Register
Reputation System ©'