UNIT 2: C L A S S I F I C AT I O N O F M AT T E R
MATTER Reflect: What is matter?
MATTER Matter: Anything that has mass and occupies space. You can describe matter in terms of quantity by mass NOT weight.
MATTER In chemistry we will look at 3 different categories or phases of matter. Each phase can be described and classified by using a PARTICLE MODEL. Solid Liquid Gas
PROPERTIES OF MATTER Solid Definite shape & volume Particle Diagram of a solid = solid particle
PROPERTIES OF MATTER Liquid Definite volume, but takes the shape of its container Particle Diagram of a liquid = liquid particle
PROPERTIES OF MATTER Gas Takes shape of container. No definite shape or volume Particle Diagram of a gas = gas particle
KINETIC MOLECULAR THEORY OF MATTER Atoms & molecules are constantly in motion (kinetic energy) in any phase. We measure the average kinetic energy of these movements of the molecules/atoms as temperature! Avg. KE = Temp.
3 PHASES OF MATTER & KMT Solids Kinetic Molecular Theory - Particles do move (vibrate) - Held tightly together - Particles are ordered - Least amount of energy
3 PHASES OF MATTER & KMT Liquids Kinetic Molecular Theory - Some particle movement - Still highly attracted to each other - Particles are disordered - Moderate amount of energy
3 PHASES OF MATTER & KMT Gases: Kinetic Molecular Theory - Lots of particle movement - Large distances between the particles - Particles are disordered - Most amount of K.E.
HOW DO YOU CHANGE BETWEEN THE PHASES? Big Idea: You can change between the 3 phases of matter by either putting energy IN or taking energy OUT.
Increase in Temp. Causes atoms/molecules to gain more energy (KE) and move faster Sublimation Fusion/Melting Vaporizing/evap Freezing solidification crystallization Condensation Deposition
Evap Condensation Melting/Fusion Freezing
http://www.kentchemistry.com/links/matter/heatingcurve.htm
Big Idea: Temperature MEASURES the average kinetic energy of particles in a sample of matter. Converting between Kelvin and Celsius: 1. Convert 50 K to the Celsius scale. 2. Normal body temperature is 310 K. Convert this to the Celsius scale. 3. Antifreeze, or ethylene glycol, boils at 199 C. Convert to the Kelvin scale.
Key Points on the temperature scales!
REAL GASES VS. IDEAL GASES L I F E V S. I D E A
KINETIC MOLECULAR THEORY OF GASES: HOW CHANGES IN TEMPERATURE AFFECT VOLUME AND PRESSURE OF A GAS. Demo Measuring a Balloon Observable Characteristic of the Gas Explain in terms of particles. REAL GASES
GASES & KMT Demo Measuring a Balloon Observable Characteristic of the Gas Gases have mass. Explain in terms of particles. Each particle has a mass (total mass of the sample is equal to the sum of the masses of the particles. REAL GASES
GASES & KMT Demo Vapor Ramp Observable Characteristic of the Gas Explain in terms of particles. REAL GASES
GASES & KMT Demo Vapor Ramp Observable Characteristic of the Gas Gases have specific densities. Explain in terms of particles. The compactness of the particles differs from gas to gas. REAL GASES
GASES & KMT Demo Compression (syringe) Observable Characteristic of the Gas Explain in terms of particles. REAL GASES
GASES & KMT Demo Compression (syringe) Observable Characteristic of the Gas Gases are compressible Explain in terms of particles. The space between particles can be reduced. REAL GASES
GASES & KMT Demo White Smoke (perfume) Observable Characteristic of the Gas Explain in terms of particles. REAL GASES
GASES & KMT Demo White Smoke (perfume) Observable Characteristic of the Gas Gases diffuse Explain in terms of particles. Because motion is random, given enough time particles will spread out evenly/randomly in the given space. REAL GASES
When a smelly gas such as a deodorant is let loose in a room, its particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions. They eventually spread through the whole room. This is diffusion. Diffusion in gases is quick because the particles in a gas move quickly. It happens even faster in hot gases
GASES & KMT Demo Ethanol Canon (potato gun) Observable Characteristic of the Gas Explain in terms of particles. REAL GASES
GASES & KMT Demo Ethanol Canon (potato gun) Observable Characteristic of the Gas Gases exert pressure. This pressure exists as a force. Explain in terms of particles. Particles collide more (create pressure) in smaller spaces or when they are moving faster. REAL GASES
Big Idea Pressure: Pressure is created when atoms/molecules collide with other particles or the walls of their container.
KMT & IDEAL GASES
THEORETICAL CHARACTERISTICS OF AN IDEAL GAS Gases: straight lines. Postulate #1 Gas particles travel in IDEAL GASES
THEORETICAL CHARACTERISTICS OF AN IDEAL GAS Gases: Postulate #2 Particles collide with the walls of the container & each other with elastic collisions. Elastic collisions = Complete transfer of energy. IDEAL GASES
INELASTIC VS. ELASTIC COLLISIONS
There are no bonds between the particles in a gas, so they are free to move in any direction. They strike the walls of their container and create a pressure.
THEORETICAL CHARACTERISTICS OF AN IDEAL GAS Gases: Postulate #3 Particles have no volume themselves. (Exist as points) IDEAL GASES
THEORETICAL CHARACTERISTICS OF AN IDEAL GAS Gases: Postulate #4 There are no attractive forces between molecules IDEAL GASES
Big Idea Real gases act most ideal at HIGH temperatures and LOW pressure.
KMT Practice Regents Questions
PRESSURE & VOLUME Boyle s Law:
TEMPERATURE & VOLUME Charles Law:
TEMPERATURE & PRESSURE Gay Lussac/Amonton:
GAS LAWS Combined Gas Law: P 1 V 1 = P 2 V 2 T 1 T 2 (temperature must be in Kelvin)
GAS LAWS Practice Problem 1: A gas at 608mm Hg is held in a container with a volume of 545 cm 3. The volume of the container is increased to 1065 cm 3 without a change in temperature. Calculate the new pressure of the gas.
GAS LAWS Practice Problem 2: What will be the volume of a gas sample at 335 K if its volume at 273 K is 8.57 L? Assume pressure remains unchanged.
GAS LAWS Practice Problem 3: A sample of oxygen gas has a volume of 205 cm 3 when its temperature is 22.0 C and its pressure is 30.8 kpa. What volume will the gas occupy at STP? (Hint: Table A)
GAS LAWS Avogadro s Law: Gases with the same Volume (at the same temperature and pressure) have the same number of particles.
GAS LAWS Practice Regents Questions.
PLEASE CREATE AN ACCOUNT Go to testwizard.com Create an account using your gmail account Please join the class using the following code: CCOS-2CIM-XV
PLEASE GO TO GOOGLE CLASSROOM Complete the assignment U1V4 Classification of Matter RESULTS WILL BE SUBMITTED AND SENT IN FOR A GRADE!!
PURE SUBSTANCE: ONE TYPE OF PARTICLE. Definition: Made of 1 type of atom Representation: Elements Characteristics: - Cannot be broken down/separated (chemically) - Pure Substances (contains only 1 type of particle) - Written w/ symbols - 92 natural, aprox 118 total (named after people, places, Latin names, etc) - Ex: Copper, Calcium, Hydrogen, O 2, Mg, Cu, F 2
COMPOUNDS Definition: Made up of 2 or more elements chemically combined. (bonded together) Representation: Characteristics: - Chemically bonded (can be chemically separated) - Pure substance - Have different properties than the elements that make them up - Specific ratio of elements within the compound - Written with formulas Examples: Copper (II) Chloride, Sodium Chloride, H 2 O, C 6 H 12 O 6
CLASSIFICATION OF MATTER Particle Diagram Practice: Label the boxes below as an element, mixture or compound.
CLASSIFICATION OF MATTER Reflect: If solid water melts into liquid water, has the basic identity of the water changed? Explain. No, it is still water, it is just in a different phase. If water is decomposed into oxygen and hydrogen gas, has the basic identity of the water changed? Explain. Yes, it is no longer 2 hydrogens and an oxygen bonded together. The molecule has been separated into two distinct different elements.
Big Idea Regardless if matter is going through a physical change or a chemical change, the amount of matter ALWAYS STAYS CONSTANT. Amount of matter before the change = Amount of matter after the change Law of Conservation of Matter: Matter (mass) can not be created or destroyed, it just changes form.
Complete the Practice Regents Questions
SEPARATING MIXTURES BASED ON THEIR COMPOSITION: SEPARATION OF HETEROGENEOUS MIXTURES Filtration Magnetism Based on differences in phase Based on magnetic/ metallic Works on separating particles properties that do NOT dissolve. Ex: separating iron filings from a Ex: separating sand and water nonmetallic substance (sulfur). mixture
SEPARATING MIXTURES BASED ON THEIR COMPOSITION: SEPARATION OF HOMOGENEOUS MIXTURES Distillation Based on differences in boiling points Separates liquids from each other. Liquid w/ the lower boiling point boils off first. Ex: separating crude oil Chromatography Based on differences in solubility & polarity Ex: separating plant pigments or ink
SEPARATING MIXTURES BASED ON THEIR COMPOSITION: SEPARATION OF HOMOGENEOUS MIXTURES Evaporation/Crystallization: For use in separating solids dissolved in a liquid. Ex: aqueous salt solution (separating the salt from salt water).
KINETIC MOLECULAR THEORY Kinetic Molecular Theory: The theory of the movement of molecules at different pressures and temperatures.
GASES & KMT Temperature: Total average kinetic energy of particles Pressure: Sum of collisions between particles/walls of container
GAS LAWS II Reflect: Explain, in terms of kinetic molecular theory, why the pressure increases in a gas sample if you increase temperature (assume the volume remains constant)
GAS LAWS II Graham s Law: The lighter a gas is, the quicker it diffuses (or effuses goes through a small hole). Which gas would diffuse (or effuse) fastest? CH 4 CO 2 He H 2
GAS LAWS II Dalton s Law of Partial Pressures: The total pressure of a gas is equal to the sum of the partial pressures of the individual gases that make up the sample. P t = P a + P b + P c.
GAS LAWS II Practice Problem 1: What is the atmospheric pressure if the partial pressure of nitrogen, oxygen and argon are 604.5 mm Hg, 162.8 mm Hg, and 0.5 mm Hg, respectively?
GAS LAWS II Practice Problem 2: If the total pressure of a gas sample is 33.9 atm, what is the partial pressure of an unknown gas if the other gases have partial pressures as follows: oxygen gas is 10.4 atm, hydrogen 7.8, and carbon dioxide is 4.2 atm?
CLASSIFICATION OF MATTER Reflect: State the term for as many phase changes as you can.
CLASSIFICATION OF MATTER
PURE SUBSTANCE: ONE TYPE OF PARTICLE. Definition: Made of 1 type of atom Representation: Elements Characteristics: - Cannot be broken down/separated (chemically) - Pure Substances - Written w/ symbols - 92 natural, aprox 118 total (named after people, places, Latin names, etc) - Ex: Copper, Calcium, Hydrogen, O 2, Mg, Cu, F 2
COMPOUNDS Definition: Made up of 2 or more elements chemically combined. (bonded together) Representation: Characteristics: - Chemically bonded (can be chemically separated) - Pure substance - Have different properties than the elements that make them up - Specific ratio of atoms - Written with formulas Examples: Copper (II) Chloride, Sodium Chloride, H 2 O, C 6 H 12 O 6
CLASSIFICATION OF MATTER Particle Diagram Practice: Label the boxes below as an element, mixture or compound.
Answer Practice Regents Questions