Uploaded by Avinashpall Singh

Chemistry Test Review States of Matter

advertisement
Chemistry Test Review: States of Matter
Test Format:
-
Multiple Choice Questions on Facts
-
Short Answers (General Ideas)
-
Calculations (Conversions, Between Pressure, Monometer)
-
Interpreting Graphs and be familiar with words describing state changes (ie,
melting)
Lesson 13.1: Gases
Kinetic: The energy an object has because of its motion
Kinetic Molecular Theory states that tiny particles in ALL forms of matter are in constant
motion.
KMT as it applies to Gases:
1. Gases are composed of particles, usually molecules or atoms
- No attraction or repulsion between particles
2. Particles in gases move rapidly in constant random motion
- Only change direction when they collide with each other
3. Collisions are perfectly elastic, meaning that kinetic energy is transferred without
loss from one particle to the other
- Total kinetic energy remains constant
Note: When there are ​no particles present, there can be no collisions, thus resulting in a
vacuum.
Lesson 13.2: Liquids
When a particle is heated, it absorbs energy, some of it will be stored as potential
energy (does not raise the temperature) but the remaining energy will result in the
particles speeding up and increasing in temperature.
-
The higher the temperature = Wider range of kinetic energies
Absolute zero (O Kelvin) is when, theoretically, all particles will stop moving.
At any given temp. a
​ ll particles​, regardless of the state​ have the same average
kinetic energy.
Gases and liquids can both flow, but u
​ nlike gases, liquid particles are
attracted to each other.
Particles of a liquid vibrate and spin but do not have enough energy to escape
that bond and turn to gas (until it's heated, since more energy is being added)
Liquids and solids are known as condensed states of matter because increasing the
pressure, will not result in any changes to the volume.
● Liquid to Gas: Vaporization
● Liquid to Gas (But no heat is added): Evaporation
● Gas to Liquid: Condensation
The most energetic particles in a liquid escape first when heated, since the ones
with more energy, whatever is left will have a lower kinetic energy.
-
Mr. Bohart’s Bong experiment demonstrated that the R
​ ate of Evaporation =
Rate of Condensation.
❖ Know how to convert between pressures and how to read a manometer.
(Worksheet 1 and 2).
Boiling point = Vapour pressure of liquid is equal to the external pressure on the liquid
Normal boiling point is 101.3 kPa or 1atm or 760 torrs (etc).
Higher altitude means less atmospheric pressure, so it would take less energy to
bring water to a boiling point. (vice versa)
-
Remember: Boiling and Evaporation are COOLING processes because the
particles with the most heat and energy escape first.
When analyzing graphs, the stuff on the left side have weaker intermolecular forces
(IMF's) Right side means stronger IMF’s.
Lesson 13.3: Solids
Solid ​particles tend to vibrate about fixed points​, rather than sliding from place to
place.
Particles are highly organized; able to move but not by very much. (Crystalline)
When solids are heated they move more and more until order breaks down.
● Solid to Liquid: Melting
● Liquid to Solid: Freezing
Most solids have high melting points because the​ energy needed to break the particle
apart is very high.
●
Amorphous: Anything without a clearly defined shape or form.
●
Allotrope: Different variations of the same element (ie, diamond and graphite are
both carbon particles rearranged)
●
Unit Cell: The smallest building block of a crystal, consisting of atoms, ions, or
molecules,
Extras:
●
Be familiar with q=mc∆t
●
Know how to analyze graphs (most are labeled)
●
Pressure conversions
●
Solid to vapour: Sublimation
●
Vapour to solid: Deposition
●
Equilibrium: Two things are happening at once
●
Triple Point: All three phases of state changes are happening at once (As in video)
Download