Matter and Energy

Honors ChemistryMatter and EnergyMATTER is anything that has mass and volume.

Do you know ALL the states of matter? Kinetic Molecular Theory of MatterAssumptions:All matter consists of particles, such as, atoms, molecules, formula units.Particles are in constant motion (kinetic). These motions arevibrational (only for solids), translational, and/or rotational. Collisions are elastic.Theory explains the physical properties of matter.The state of matter of a substance depends upon the strength of attraction between particles. All 3 for liquids and gases.Vibrational

Combined MotionsTranslationalRotational Gases LiquidsSolids gas liquid solidlittle to no ordermost orderlow densityhigh density (condensed states)compressibleincompressibleno definite volume or shapedefinite volumedefinite volumetakes shape of containerdefinite shapediffuses quicklyslower diffusion ( with temp) low diffusionlow strength of attractionhigh strength of attractionStates of Matter

meltingfreezingcondensingevaporatingdepositionsublimationSolidLiquidGasProperties of MatterPhysical = A characteristic of a substance that does not involve a chemical change

Examples: texture, state of matter, density, hardness, boiling point

Properties of MatterChemical = A property of matter that describes a substances ability to participate in chemical reactions.

Examples: reacting with oxygen, light sensitivityPhysical ChangesDo NOT change the identity

Often change what the substance looks like

Examples: mixing ice tea in water, crushing a rock, freezing waterChemical ChangesAlter the identity of the substance.

The new substance has a different composition than the beginning substances.

Examples: rusting and burning

A shorthand way to express a chemical reaction is with a chemical equation.Chemical EquationsThe substances on the left side of the arrow are called the reactants. They are the starting materials in the reaction.

The substances on the right side of the arrow are called the products. They are the ending materials in a reaction.A + B C + D Examples of Chemical Equations

Signs of a Chemical ChangeGas production bubbles, odor, fizz, smoke

Color change

Release or absorption of energy light or temperature change

Formation of a precipitate a solid substance that falls out of solutionClassification of Matter

Classification of MatterPure substances: A sample of matter with a definite composition; means definite chemical and physical properties.

Includes: Elements and Compounds

ElementsMade up of one type of atom.

An atom is defined as the smallest unit of an element that maintains the properties of that element.

Cannot be separated into similar substances by chemical means.

Represented by symbols.

Elements (cont.)Can exist as atoms or molecules. A molecule usually consists of two or more atoms.

Ex. N2, O2, F2, Cl2, Br2, I2, H2, P4, S8

Elements that have more than one form are called allotropes. Ex. Carbon (graphite and diamond)Parts of the Periodic Table

Metal, Nonmetals and Metalloids (Semimetals):MetalsFound on the LEFT side of the PT

2. NonmetalsLocated on the RIGHT side of the PT

3. Metalloids - Properties of both metals & nonmetals- Good conductors of heat & electricity- High luster (shiny)- Ductile (can be drawn into thin wire)- Malleable (bends without breaking)- High melting points most solids at room temperature- High densities- Reacts with acids- Brittle (easy to break)- No luster (dull)- Neither ductile nor malleable- Nonreactive with acids- Insulators nonconductors (Semimetals)

CompoundsMade up of 2 or more different elements combined in a fixed position.

Can be separated through chemical means.

Represented by formulas.

Electrolysis allows chemists to distinguish between elements in compounds.

Examples: CO2 and H2O

Elements Vs. Compounds

Mixtures: A combination of 2 or more substances that are not chem. combined.Heterogeneous Mixture: Composed of dissimilar components; Can see the partsA.K.A. Mechanical MixtureEx. Cookie, salad, asphalt

Homogenous Mixture: Uniform structure or composition throughout A.K.A. SolutionEx. Lemonade, steel, airAlloy: A solid homogeneous mixture (14 caret gold, steel, pewter)Examples of Alloys

Brass is an alloy of copper and zinc.Steel is an alloy of carbon and iron.

Bronze is an alloy of copper and tin.Microscopic look at mixtures

Counting Atoms in CompoundStep 1: List all elements present

Step 2: Identify the coefficient

Step 3: Count the number of atoms of each element in the compound.

Step 4: Multiply the coefficient by the subscript

Step 5: Add up all the atoms

Counting AtomsNa2SO4Ca(OH)2

3 Fe2(SO3)3Separating Heterogeneous MixturesFiltration: Pour liquid through paper and collect residue (solid)

Separation of Homogeneous MixturesDistillation: Separation based on a difference in boiling points

Another Look at DistillationDistillation DemoA Closer Look at Distillation

Separation of Homogeneous MixturesCrystallization: Evaporate liquid and solid will recrystallize

Separation of Homogeneous MixturesChromatography: Separation of pigments of dye

Percent Concentration of SolutionsA measure of the amount of solute in a solution.

% Concentration = mass of solute x 100 mass of solution

Note: Solute + Solvent = Solution Energy and ChangeEnergy is the capacity to do work.

All physical and chemical changes require energy.

Endothermic - describes a process in which heat is absorbed from the environment.

Exothermic describes a process in which heat is released into the environment.Law of Conservation of Energy Energy is neither created, nor destroyed. It just changes forms.

Types of EnergyPotential energy stored energyKinetic energy energy of motion

Heat TransferTransfer of heat may not affect temperature.

During a phase change, the temperature will remain constant until all of the substance has changed state.

The temperature will increase when a substance is a solid, liquid, or gas.Kinetic Theory of MatterGases posses the greatest amount of kinetic energy.

Two factors that determine the state of matter of a substance: speed of particles and distance

There are two factors contribute to the attraction between the particles.Kinetic Theory of MatterSubstances change phases when they overcome these attractions.

The overall kinetic energy will not change until the entire substance has completely changed.

Comparison of the three states of matter

Kinetic-Molecular Theory and Gases1. Gases are small particles that have mass. These particles are usually molecules, except for the Noble Gases.

2. The particles in gases are separated by relatively large distances.

3. The particles in gases are in constant rapid motion (random).4. Gases exert pressure because their particles frequently collide with the walls of their container and each other.

5. Collisions of gas particles are perfectly elastic.

Inelastic CollisionElastic CollisionGas particles do not slow down when hitting each other or the walls of their container.

6. Temperature of a gas is simply a measure of the average kinetic energy of the gas particles. High temp. = high KE, Low temp. = low KE

7. Gas particles exert no force on one another. Attractive forces are so weak between particles they are assumed to be zero.

Boyles Law Pressure - Volume Relationship. The pressure & volume of a sample of gas at constant temperature are inversely proportional to each other.IndirectP1V1 = P2V2

Boyles Law

Boyles Law Problem A gas has a volume of 300. mL under a pressure of 740. mm of mercury. If the temperature remains constant, calculate the volume when under a pressure of 750. mm Hg.P1V1 = P2V2

Charles Law: Temperature - Volume Relationship. At constant pressure the volume of a fixed amount of gas is directly proportional to its absolute temperature. Law assumes n is constant.Direct

*Temperatures must be in Kelvin! K = C + 273

Balloon in cool and cold water:

Charless Law

A gas sample at 83C occupied a volume of 1470 m3. At what temperature, in C, will it occupy a volume of 1250 m3?V1 = 1470 m3V2 = 1250 m3T1 = 83C = 356 KT2 = ?

T2 = 30.CCharles Law ProblemThe pressure of a fixed volume of gas is directly proportional to its absolute temperature. Law assumes n is constant.

Direct P1 = P2

T1 T2*Temperatures must be in Kelvin! K = C + 273Gay-Lussacs LawGay-Lussacs Law

Before a trip, the pressure in a car tire was 1.80 atm at 21oC. At the end of the trip, the pressure gauge reads 1.90 atm. Calculate the temperature, in Celsius, of the air inside the tire at the end of the trip. Assume the tire volume does not change. P1 = 1.80 atmP2 = 1.90 atmT1 = 21C = 294 KT2 = ?

T2 = 37CGay-Lussacs Law The Combined Gas Law

Choyles This law can be used to determine how changing two variables at a time affects a third variable.

A gas occupies 72.0 mL at 25 C and 198 kPa. Convert these to standard conditions. What is the new volume?P1 = 198 kPaP2 = 101.325 kPa V1 = 72.0 mLV2 = ?T1 = 298 KT2 = 273 K

Gases in a mixture behave independently of each other.The total pressure of a gaseous mixture equals the sum of the partial pressures of the individual gases in a mixture.Partial pressure = individual pressure of a gas in a mixturePT = p1 + p2 + p3 + Daltons Law of Partial Pressures

Daltons Law of Partial Pressures:

Example #1) A flask contains a mixture of oxygen, argon, and carbon dioxide with partial pressures of 745 torr, 0.278 atm, and 391 torr respectively. What is the total pressure in the flask?

PT = Pa + Pb + Pc + In the lab, gases are collected over water (water displacement). As a result, water vapor contributes to the total pressure.PT = pdry gas + pwater vaporwhere pwater vapor varies with temperatureDaltons Law of Partial PressuresT (oC)P (mm Hg)T (oC)P (mm Hg)T (oC)P (mm Hg)T (oC)P (mm Hg)04.62625.25197.276301.414.92726.752102.177314.125.32828.453107.278327.335.72930.054112.579341.046.13031.855118.080355.156.53133.756123.881369.767.03235.757129.882384.977.53337.758136.183400.688.13439.959142.684416.898.63542.260149.485433.6109.23644.661156.486450.9119.83747.162163.887468.71210.53849.763171.488487.11311.23952.464179.389506.11412.04055.365187.590525.81512.84158.366196.191546.11613.64261.567205.092567.01714.54364.868214.293588.61815.54468.369223.794611.01916.54571.970233.795634.02017.54675.771243.996658.02118.74779.672254.697682.02219.84883.773265.798707.32321.14988.074277.299733.22422.45092.575289.1100760.02523.8

EudiometerPiece of glassware used to measure the change in volume of a gas. It is similar to a graduated cylinder. It is closed at the top end with the bottom end immersed in water or mercury. The liquid traps a sample of gas in the cylinder, and the graduation allows the volume of the gas to be measured.

Example #2) Atmospheric pressure is 101.3kPa, and air is a mixture of N2, O2, and Ar as 78.0%, 21.0%, and 1.0%, respectively. Calculate the partial pressure of O2.

21.3 kPaExample #3) Hydrogen gas is collected by water displacement at 18C. Air pressure on that day is 744.0 mm. Calculate the pressure due to the dry hydrogen gas. 728.5 mm Hg