What is the Kinetic Molecular Theory?
The Kinetic Molecular Theory, commonly referred to as the Kinetic Theory of Matter, explains the properties of matter. All matter is made of atoms and molecules that act like tiny particles. These particles are always in motion. The higher the temperature is the faster they will move. If they are the same temperature, the bigger particles move slower than the smaller particles.
The Kinetic Molecular Theory, commonly referred to as the Kinetic Theory of Matter, explains the properties of matter. All matter is made of atoms and molecules that act like tiny particles. These particles are always in motion. The higher the temperature is the faster they will move. If they are the same temperature, the bigger particles move slower than the smaller particles.
3 Main Types of Phases
Solid
Rigid, fixed structure Very small distance between particles Moves in vibration |
Liquid
Shape of container Small distance between particles Fluid movement |
Gas
Shape of container Large distance between particles Very fast, random movements |
Plasma
Phase where atoms lose their electrons Very high temp Not one of the 3 main types of matter |
Phase Changes
Energy is the ability for matter to change or move. Energy is required to change the phases of matter form one to another. There are six different phase changes, melting, evaporation, sublimation, freezing, condensation, and deposition.
Energy is the ability for matter to change or move. Energy is required to change the phases of matter form one to another. There are six different phase changes, melting, evaporation, sublimation, freezing, condensation, and deposition.
Melting
Solid to Liquid Ex. Ice to water |
Evaporation
Liquid to Gas Ex. Puddles disappearing as temperature increases |
Sublimation
Solid directly to Gas (No liquid) Ex. Ice cubes shrinking over time |
These three phase changes are endothermic, meaning they're absorbing energy in the form of heat.
Freezing
Liquid to Solid Ex. Hot candle wax cooling off |
Condensation
Gas to Liquid Ex. A cold drink "sweating" |
Deposition
Gas directly to Solid (No liquid) Ex. Frost on grass early in the morning |
These three phase changes are exothermic, meaning they're releasing energy in the form of heat.
Standard Temperature Pressure
Each pressure has a STP, Standard Temperature Pressure.
Each pressure has a STP, Standard Temperature Pressure.
Standard Pressure Values
At sea level, the pressures can be recorded as: 14.7 psi (pounds per square inch) 29.9 inHg (inches of Mercury) 760 mmHg (millimeters of Mercury) 760 torr 1 atm (atmosphere) 101.325 kPa (kilopascals) All of these values are equal to each other 29.9 inHg = 101.325 kPa 760 torr = 760 mmHg 1 atm = 14.7 psi |
Standard Temperature Values
0C (Zero degrees Celsius) 273 K |
Conversions
Pressure Conversions
Ex. 421 torr = ? Atm 1. Draw a fence, Put 421 torr on outside of the fence. 2.You're getting rid of torr, it goes on bottom. You're finding Atm, it goes on top. 3. Use the STP as your values. 4. Solve 421 torr | 1 Atm = .554 Atm | 760 torr |
Temperature Conversions
F = (9/5) C + 32 C= (5(F - 32)) / 9 K = 273 + C C = K - 273 If you are given Fahrenheit, you MUST convert it first. |
Kinetic Energy
Kinetic Energy is energy that's in motion, it is the energy of a moving object. Matter is made from particles in motion, so particles have kinetic energy.
KE = (mv^2)
2
or
KE = (ma)
2
Kinetic Energy is measured in Joules, J.
1 J = 1kg ● m^2
s^2
The mass must be in kg, if not you have to convert, and the velocity must be in m/s or m^2/s^2.
Ex. Calculate the KE of a car with a mass of 6780 grams and a speed of 36 km/h.
Kinetic Energy is energy that's in motion, it is the energy of a moving object. Matter is made from particles in motion, so particles have kinetic energy.
KE = (mv^2)
2
or
KE = (ma)
2
Kinetic Energy is measured in Joules, J.
1 J = 1kg ● m^2
s^2
The mass must be in kg, if not you have to convert, and the velocity must be in m/s or m^2/s^2.
Ex. Calculate the KE of a car with a mass of 6780 grams and a speed of 36 km/h.
6780 g | 1 kg = 6.780 kg
| 1x10^-3 36 km | 1x10^-3 | 1 hr = 10 m/s hr | 1 km | 3600 sec |
KE = mv2 = 6.780 (10)^2 = 339 = 340 J
2 2 |
How to Read Phase/ Energy Diagrams
Heat v Temperature
Temperature and heat aren't the same thing. Temperature is the measure of the Average Kinetic Energy of particles in a sample of matter, while heat is the energy transferred between samples of matter because of a difference in their temperatures.
Temperature and heat aren't the same thing. Temperature is the measure of the Average Kinetic Energy of particles in a sample of matter, while heat is the energy transferred between samples of matter because of a difference in their temperatures.
Specific Heat
Physical property of a substance used to compare heat absorption capabilities for different materials. (Heat Capacity) Cp = q m●T Cp- Specific Heat q- Energy Required m- Temp of 1 gram T- Kelvins |
Change in Temperature
T = q m●Cp Heat Energy q = Cp ● m ● T Mass m = q Cp●T |