Warm-up 9/7/10 • New Unit – Matter and Energy • Warm-up #1: Describe an apple.
Objectives • Students will apply their understanding of physical and chemical properties and changes. (CS 4.12.1*, CLG 4.1.1*)
AGENDA • Discuss warm-up • Notes on Matter • Matter Video Clip • Wrap-up
Chemistry Unit Two Matter and Energy
Matter • Matter • anything that has a mass and takes up space. • Law of Conservation of Mass/Matter • Matter can be described using ..
PROPERTIES Types of Properties
Characteristics of Matter • Physical Properties • Examples: • Color,smell, taste, hardness, density, texture, melting/boiling/freezing points, magnetic attraction, solubility, electrical conductivity, temperature, state or phase
Two Types of Physical Properties • Extensive • Intensive • Depends on the type of matter NOT size of sample • examples: color, melting point, specific heat, density, appearance, etc…
Characteristics of Matter • Chemical Properties • Examples: • Oxidation, Corrosion, Hydrolysis, Combustion, Flammability, Reaction to Acid or Base.
Two Types of Changes • Physical Change • . • Does not change the chemical composition of the matter!!
Characteristics of Matter • Chemical Change • forms a new substance that has different physical and chemical properties than the original substance. • Also known as a .
World of Chemistry • http://www.learner.org/resources/series61.html?pop=yes&pid=797
Kinetic Theory • All matter is made of tiny particles in . • Potential Energy (PE) • energy due to the position or condition • at the atomic level: • the distance between the particles • = lower PE = higher PE • Kinetic Energy (KE) • energy due to motion • =higher KE = lower KE
Plasma • extraordinary state of matter • consists of high energy particles • electrons are stripped from their nuclei • examples: *Most Abundant State of Matter in the Universe!*
Phase Changes Changes of State • energy (heat) to a substance causes phase changes • The potential energy of the particles is • During a phase change, temperature
Phase Changes • Melting • Δ (adding energy) • Freezing • Δ (removing energy) • Melting point & freezing point of a substance occur temperature.
Phase Changes • Boiling • Δ (adding energy) • Evaporation • Δ (adding energy) • Condensation • Δ (removing energy) • Difference between boiling & evaporation: • a specific temp. below the surface • any temp. at the surface
Phase Changes • Deposition • Δ (removing energy) • Examples: • Sublimation • Δ (adding energy) • Examples:
Phase Change Graphs (T vs t) Liquid Melting Solid AB -heat Δ KE -move faster -temp. -solid BC -heat Δ PE -get farther apart -temp. stay same -melting CD -heat Δ KE -move faster -temp. -liquid
Phase Change Graph (T vs t) Gas Boiling DE -heat Δ PE -get farther apart -temp. stay same -boiling EF -heat Δ KE -move faster -temp. -gas
Phase Change Graph (T vs t) A C B E D F
Phase Change Graph (T vs t) A B C D E F
Phase Change Graph (T vs t) Boiling Freezing Melting What is the boiling point? What is the melting point? What is the freezing point?
Phase Change Graph (T vs t) If melting & freezing points occur at the same temperature, how do you know which change is occurring?
Phase Change Graph (T vs t) What is this substance? - How do you know? -
Heat Calculations • Heat (q) • Energy transferred from an object at a higher temperature to an object at a lower temperature. (heat lost = -heat gained) • q = mcT • q=mHfus • q=mHvap
Heat Calculations • A 10.0g sample of iron at 50.4oC is cooled to 25.0oC in 50.0g of water. Calculate the amount of heat lost by the iron. ciron= 0.449 J/goC *How much heat is gained by the water? • A 2.1g ice cube at –8.0oC melts completely and warms to 12.5oC. How much heat was required? Hfus ice = 334 J/g cice = 2.03 J/goC cwater = 4.18J/goC
Classification of Matter Matter
Matter • Pure Substances • Mixtures • Element
Matter (cont’d) • Compound • Homogeneous Mixtures • Heterogeneous Mixture
Classifications of Mixtures • Solutions • Colloids • Suspension
Solutions • SOLUTION • ELECTROLYTE
Types of Solutions • Gas-Gas • Liquid-Gas • Gas-Liquid • Liquid-Liquid • Solid-Liquid • Solid-Solid
Characteristics of Solutions • Homogeneous Mixture • Soluble- • Insoluble • Immiscible • Miscible
Solvation • When a solid solute is placed in a solvent, the solvent particles completely surround the surface of the solid solute. • If attractive forces between the solute particles and the solvent are greater than the attractive forces holding the the solute particles together, the solvent particles pull the solute particles apart and surround them.
- + + + - + + + - - - + - + + - + - + + - + - - + - + + + - + - - + + + + Process of Solvation H2O H = O = - - + - + NaCl Na = Cl = + -
Water- Universal Solvent • molecule • Dipoles allow
Solvation Factors • Agitation • Increasing surface area of solute • Increasing temperature of solvent
Heat of Solution • Endothermic- • Exothermic-
Solubility • Refers to • g / 100 g • vs vs
Concentration • How much solute is dissolved in a specific amount of solvent
Molarity • / • Calculate the molarity of 1.60 L of a solution containing 1.55 g of dissolved KBr? • How many grams of CaCl2 would be dissolved in 1.0 L of a 0.10M solution of CaCl2?
Diluting Solutions • M1V1 = M2V2 • What volume of a 3.00 M KI stock solution would you use to make ).300 L of a 1.25 MKI solution?
Colligative properties of Solns • Physical properties of solutions that are affected by the number of particles but not the identity of dissolved solute particles