TOPIC 4 PHYSICAL BEHAVIOR OF MATTER. Phases of Matter The 3 phases of matter are: solid, liquid &...
-
Upload
jessie-fitzgerald -
Category
Documents
-
view
218 -
download
1
Transcript of TOPIC 4 PHYSICAL BEHAVIOR OF MATTER. Phases of Matter The 3 phases of matter are: solid, liquid &...
TOPIC 4PHYSICAL BEHAVIOR
OF MATTER
Phases of Matter
The 3 phases of matter are: solid, liquid & gas.
Heat is exchanged during heating, cooling & phase changes.
The kinetic molecular theory explains the behavior of gases.
Mixtures separate by physical means.
Phases of Matter
The solid phase contains matter held in a rigid form.
A substance in this phase has a definite volume and shape.
Strong attractive forces hold the particles together and true solids have a crystalline structure.
Phases of Matter
The liquid phase has particles that are not held together as rigidly as the solid phase.
Particles are able to move which prevents the liquids from having a definite shape but are held together with enough attractive forces to give a definite volume.
Phases of Matter
The gaseous phase has minimal attractive forces holding them together.
Gases have neither a definite shape nor a definite volume, therefore, they will spread out indefinitely unless confined.
Heating & Cooling Curves
As temperature increases, kinetic energy increases.
Heating & Cooling Curves
Melting, also known as fusion, occurs because the particles
have enough kinetic energy to break their bonds.
Heating & Cooling Curves
During melting, temperature remains constant even though heat is being added
and thus potential energy increases but since the temperature remains constant so
does the kinetic energy.
Heating & Cooling Curves
Boiling, also known as vaporization, occurs because the particles have even more
kinetic energy breaking the liquid bonds.
Heating & Cooling Curves
Kinetic energy increases during the heating of a solid, liquid and gas.
Heating & Cooling Curves
Potential energy increases and kinetic energy remains
constant during melting of a solid and the boiling of a liquid.
Heating & Cooling Curves
The reverse of boiling is condensation and the reverse of melting is
freezing.
Heating & Cooling Curves
Sublimation is when a solid changes directly to a gas
and the reverse process is called deposition.
Temperature
Temperature is a measure of the average kinetic energy of particles measured in °C or in K and heat flows from higher temperature to
lower temperature.
Temperature
K = °C + 273 (on RT)
Heat Energy
Heat is a measure of the amount of energy transfer
and is measured in calories or joules.
Heat EnergyThe amount of heat given off or absorbed can be
calculated using the formula: q = mCΔT; where q is heat measured in Joules, m is mass
measured in grams, C is specific heat measured in J/g·K, ΔT is change in temperature measured
in °C or K.
Heat Energy
The heat of fusion is the amount of heat needed to convert a
solid to liquid and the value is 334 J/g found in Table B.
Heat Energy
The heat of vaporization is the amount of heat needed to
convert a liquid to gas and the value is 2260 J/g found in Table
B.
Heat Energy
Melting and boiling are endothermic processes, requiring heat; freezing and condensation
are exothermic processes, releasing heat.
Behavior of Gases
The kinetic molecular theory is a model/theory used to
explain the behavior of gases.
Kinetic Molecular Theory Ideas
Particles are in constant, random, straight-line motion
Particles collide with each other & walls; transfer energy; no net loss
Kinetic Molecular Theory Ideas Particles separated by
great distances, therefore, volume by themselves is negligible
Particles do not attract each other
Behavior of Gases
The two elements most like a real gas are hydrogen &
helium.
Behavior of Gases
Gases are most ideal at low pressure and high
temperature.
Behavior of Gases
Avogadro’s hypothesis states that when the volume, temperature &
pressure of two gases are the same, they contain the same
number of molecules.