CHAPTER 10- States of Matter



Solids, liquids and gases



The Kinetic Molecular Theory explains the behavior of moving particles.
- if a gas obeys all parts of the kinetic molecular theory, the gas is idea.
- Real gases exist in our world.
- The more energy a particle has, the faster it moves. Ke= ½ MV2

*The phase of a substance depends on a battle between a substance depends on a battle between a substances kinetic energy and the strength of intermolecular forces.

states_of_matter.gif
Intermolecular Forces (weakest to strongest)
1) London dispersion forces- arise from the random movement of electrons.

external image hameroff13.jpg



2) Dipole-dipole forces- found only in polar molecules
- dipoles are always there, hense dipole-dipole is stronger.
external image Dipole-dipole-interaction-in-HCl-2D.png


3) Hydrogen bonding-
- strongest of the 3 intermolecular forces.
- exist in compounds where the Hydrogen is directly bonded to N, O, or F.


Pressure- a force exerted over a given area

Barometer- atmostpheric pressure Manometer- measures gas pressure

external image Barometer.gif external image Manometer.jpg


Boiling point- temperature at which the vapor pressure of a liquid is equal to the atmospheric pressure

Vapor pressure - is the pressure resulting from the evaporation of a liquid
Three Thermometers Showing the Freezing and Boiling Point of Water in Kelvin, Celsius and Fahrenheit
Three Thermometers Showing the Freezing and Boiling Point of Water in Kelvin, Celsius and Fahrenheit

EXAMPLES-


1) The atmospheric pressure is 1.12 atm. Find gas B's pressure. 1.12 760 mm Hg = 851 mm Hg - 18
1 atm = 833 is the pressure

For that example problem, 760 comes from the conversion for 1 atmosphere. Then you just multiply 1.12 and 760 together, which equals 851 and then subtract 18, which is the height of the manometer is 18. The total then equals 833.


2) If the atmospheric pressure is 729 mm Hg, what is the pressure of Gas B?
729- 15 = 714 mm Hg

15 is the height of the gas in the manometer, you would just need to subtract that from the atmospheric pressure in order to get the final answer.