Phases of Matter

Phases An element or a compound can exist in either a solid, liquid or gas These 3 types are called the phases of matter

Solid The solid phase has particles that are held very rigidly. It has a definite volume and shape. It has very strong connective forces between the particles

Liquid Particles in a liquid are held together, but not as tightly as a solid is. Because the particles are mobile, it has no definite shape. But it does have a definite volume

Gas Gas particles have almost no attraction to each other, so the particles can spin anywhere. Gas will spread to fill whatever container it is put in It has no volume and no shape

Heating A solid is solid because the particles are held together tightly, and a gas is a gas because it is not held together at all. If something solid is heated the heat added to the molecule makes it move faster and it will break to connections between the other molecules.

Heating curve As heat is added molecules gain KINETIC Energy. This means the molecules spin faster and faster.

Heating curve When it has just enough energy to break the bonds it is changing phases. At the straight lines the temperature does not change but the POTENTIAL energy changes

Heating curve The last bit of heat added to melt something is called heat of fusion. The last bit of heat needed to vaporize something is called heat of vaporization

Changes of matter Solid -  liquid = Melting Liquid  solid = Freezing Liquid  gas =Vaporization Gas  Liquid = Condensation Solid  gas = Sublimation Gas  solid = deposition

Temperature Temperature is a measure of the Average Kinetic Energy of a substance. And when two substances are in contact heat always moves from hot to cold until everything evens out.

Kelvin Absolute zero is the temperature where no energy at all is present. It is called 0 degrees kelvin which is equal to -273 celcius. The reference table gives a conversion.

Heat We need a way to measure how much heat is added or lost by something. Heat is measured in a unit called joules.

Heat If something has it’s temperature changed but doesn’t change state…. (Ex. If something is heated from 20c  50 c ) We have a formula to measure the heat added.

Heat Q= mc t This means heat ( Q) = mass (M) X Specific heat (c) X change is temp (T) Ex. How many joules are used to heat 50g of water from celcius

Heat of fusion If we want to know how much energy it took to melt something ( heat of fusion) We use Q= MHf EX. How much heat is needed to melt 32 grams of water

Heat of vaporization If we want to know how much heat is needed to boil something we use Q=MHf EX. How much heat is needed to boil 23 grams of water.

Behavior of gasses The kinetic molecular theory is used to explain the behavior of gasses. It has 4 rules 1- Gas particles are in random STRAIGHT line motion

Behavior of gasses 2- Collisions of gas particles are perfectly elastic ( this means all energy lost by 1 particle when it hits another is transferred to the second) 3- Gas particles are so small, and the distance spereating them is so big that the volume of the gas is negligable

Behavior of gasses 4- Gas particles have no attraction for each other.

Preasure & volume As the volume a gas has to move around in goes down the preasure the gas exerts on the walls go up. The same is true in the opposite direction.

Temp & preasure As the temp of a gas increases the molecules move faster and collide with the walls more. This means as temp goes up so does pressure.

Combined gas laws If we know the volume or preasure of gas at one point, and then we change the temp we can determine the new volume or preasure

Combined gas law Ex. What volume will a gas occupy if the preasure on 3 liters of gas goes from 4- 6 ATM, Assume the temp remained constant

Ideal vs Non ideal gas An ideal gas is a gas that does exactly what we expect it to do. Meaning – no attractions, no volume, random motion, & elastic collisions. To do this the gas must have space to move & energy to move ( Heat)

Non ideal If a gas is given very little space to move (meaning A LOT of pressure) Or it is cooled A LOT (So it has no energy) it is called a NON IDEAL GAS Low pressure & High Temp= Ideal High pressure & Low Temp= Not Ideal

Numbers of gas particles The rule for number of particles is that any2 gasses are equal is they take up the same amount of space Ex 3 liters of neon gass has the same number of particles as 3 liters of helium gas

Seperation of mixtures When 2 things are physically mixed they can be spereated using there different properties 1) Filtration 2) Distilation