Gases
This presentation is the property of its rightful owner.
Sponsored Links
1 / 16

Gases Part 1 PowerPoint PPT Presentation


  • 97 Views
  • Uploaded on
  • Presentation posted in: General

Gases Part 1. Elements that exist as gases at 25 0 C and 1 atmosphere. Physical Characteristics of Gases. Gases assume the volume and shape of their containers. Gases are the most compressible state of matter. Gases will mix evenly and completely when confined to the same container.

Download Presentation

Gases Part 1

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Gases part 1

Gases

Part 1


Gases part 1

Elements that exist as gases at 250C and 1 atmosphere


Gases part 1

Physical Characteristics of Gases

  • Gases assume the volume and shape of their containers.

  • Gases are the most compressible state of matter.

  • Gases will mix evenly and completely when confined to the same container.

  • Gases have much lower densities than liquids and solids.


Gases part 1

Force

Area

Barometer

Pressure =

(force = mass x acceleration)

Units of Pressure

1 pascal (Pa) = 1 N/m2

1 atm = 760 mm Hg = 760 torr

= 101,325 Pa = 14.7 psi = 29.92 in. Hg


Gases part 1

10 miles

0.2 atm

4 miles

0.5 atm

Sea level

1 atm


Boyle s law

Boyle’s Law

P α 1/V

This means Pressure and Volume are INVERSELY PROPORTIONAL if moles and temperature are constant (do not change). For example, P goes up as V goes down.

P1V1 = P2 V2

Robert Boyle (1627-1691). Son of Earl of Cork, Ireland.


Charles s law

Charles’s Law

If n and P are constant, then V α T

V and T are directly proportional.

V1 V2

=

T1 T2

  • If temperature goes up, the volume goes up!

Jacques Charles (1746-1823)


Gay lussac s law

Gay-Lussac’s Law

If n and V are constant, then P α T

P and T are directly proportional.

P1 P2

=

T1 T2

If temperature goes up, the pressure goes up!

Joseph Louis Gay-Lussac (1778-1850)


Combined gas law

Combined Gas Law

  • The good news is that you don’t have to remember all three gas laws! Since they are all related to each other, we can combine them into a single equation. BE SURE YOU KNOW THIS EQUATION!

    P1 V1 P2 V2

    =

    T1 T2


Gases part 1

STP in chemistry stands for Standard Temperature and Pressure

Standard Pressure = 1 atm (or an equivalent)

Standard Temperature = 0 deg C (273 K)

STP allows us to compare amounts of gases between different pressures and temperatures


Avogadro s law

Avogadro’s Law

Va number of moles (n)

Constant temperature

Constant pressure

V = constant x n

V1/n1 = V2/n2


Ideal gas equation

Boyle’s law: V a (at constant n and T)

Va

nT

nT

nT

P

P

P

V = constant x = R

1

P

Ideal Gas Equation

Charles’ law: VaT(at constant n and P)

Avogadro’s law: V a n(at constant P and T)

R is the gas constant

PV = nRT


Gases part 1

R =

(1 atm)(22.414L)

PV

=

nT

(1 mol)(273.15 K)

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP).

PV = nRT

R = 0.082057 L • atm / (mol • K)

Experiments show that at STP, 1 mole of an ideal gas occupies 22.414 L.


Gases part 1

m

V

PM

=

RT

dRT

P

Density (d) Calculations

m is the mass of the gas in g

d =

M is the molar mass of the gas

Molar Mass (M ) of a Gaseous Substance

d is the density of the gas in g/L

M =


Gases part 1

M =

dRT

P

A 2.10-L vessel contains 4.65 g of a gas at 1.00 atm and 27.00C. What is the molar mass of the gas?


  • Login