physical behavior of matter
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DESCRIPTIONPhysical Behavior of Matter. Text Book: Chapters 10, 11, and 12 Review Book: Topic 4. Review: States/phases of Matter. Matter can come in the form of: Solid : matter that has a definite shape and volume. True solids have a “crystalline” structure. - PowerPoint PPT Presentation
Physical Behavior of MatterText Book: Chapters 10, 11, and 12Review Book: Topic 4
1Review: States/phases of MatterMatter can come in the form of:Solid: matter that has a definite shape and volume. True solids have a crystalline structure.Liquid: a form of matter that flows, has fixed volume, and takes the shape of its container.Gas: matter that has no definite shape or volume, it adopts the shape and volume of its container
LOOK at the TABLE!2
A lot of space between particles. Particles rotate, vibrate and move around
Little space between particles. Particles rotate and vibrate.
No space between particles. Particles only vibrate without changing position.3Things to knowEntropy refers to randomness of atoms. So, Gas would have the greatest entropy.Enthalpy is the amount of heat retained
5Heating and Cooling CurvesPhase changes are physical changes - they do not involve a change in the composition of a substance.We will now look at two types of graph curves that show s substance going from the solid to gas phase (Heating Curve) and reversely turning from gas to solid (Cooling Curve).
REMEMBER: There are two types of reactions- Endothermic (absorb heat) and Exothermic (release heat).6Background: Kinetic energy: is energy a body possesses because it is in motionlike when atoms are in motion. The average kinetic energy of the atoms or molecules is measured by the temperature of the body.Potential energy: is the capacity for doing work that a body possesses because of its position or conditionthink of it as an atom waiting to get into motion, its stored energy it can used.Example: you are at the start line if a racethis is Potential energy. Once you begin to runthis is kinetic energy.** Motion (kinetic energy) produces heatso as kinetic energy increases the phase will go from solid to liquid.
7Vocabulary to know:
fusion, melting: solid to liquid phase changeboiling, vaporization: liquid to gas phase change evaporation: liquid to gas phase change of the particles on the outer surface onlysolidification, freezing: liquid to solid phase changecondensation: gas to liquid phase change
Heating CurveWhen particles have enough kinetic energy (moving energy due to gain in heat energy) to break bonds holding them in solid phase- they melt or go through FUSION.Amount of liquid increases and solid decreases.Temperature continues until boiling point is reached, VAPORIZATION then begins (when attractive forces are broken among atoms that were keeping them in liquid phase).
Melting PointBoiling Point10
11Cooling CurveThe opposite of a Heating Curve
13Skipping a StepSublimation: Solid to gas phase change (the substance is said to be Sublime) Ex: Dry IceDeposition: gas to solidSublimation and Deposition are OPPOSITES!
Review:HW 1: Review book15Temperature and ScalesThe temperature of a substance is a measure of the average kinetic energy of its particles.Heat is the measure of energy transferred from one substance to another.Scientists use Kelvin and Celsius as their scale for temperature.Formula the know: Kelvin= Celsius + 273Celsius temperatures to know: 0= freezing pt of water 100= boiling pt of water -273= absolute zero
16RememberONLY HEAT IS TRANSFERED! Coldness does not transfer, things become cold or cooler when their heat is transferred somewhere else. Ex #1: if your nose is cold and you touch it with your warm hands, your hands become cooler due to the heat transfer from hands to nose.Ex#2: Ice melting- ice is cold, and melts when it absorbs heatmaking it turn into a liquid.
17Question:What Kelvin Temperature is equivalent to 35C?
Work: K= C+ 273 K= 35 + 273 K= 308HW #2: Review Book
18Measurement of Heat EnergyThe amount of heat given off or absorbed in a reaction can be calculated by: q=mCTWhere: q= heat (in joules) m= mass of the substance C= specific heat capacity of the substance T= Change in temperature (Final Temp- Initial Temp)** All the formulas you will need are on Table T of your formula sheet!19Example:Question: How many joules are absorbed when 50.0 grams of water are heated from 30.2C to 58.6C?
Where do we start?Always write down what you know and what you are looking for!!We Know: mass= 50.0 g Cwater= 4.18 J/g xC (found on table B) T= (58.6C- 30.2C)= 28.4CWe are looking for:q= joules
20ExampleContPlace all the factors you know into the formula and solve. q=mCT q= (50.0 grams)(4.18 J/gram x C) (28.4C) q= 5936 J or 5.94 x 103 J
Answer: 5.94 x 103J
21Heat of FusionThe amount of heat needed to convert a unit mass of a substance from solid to liquid at its melting point is called HEAT OF FUSION.The heat of fusion of solid (ice) water at 0C and at 1 atmosphere is 334 J/gHeat absorbed increases the potential energy of the substance without increasing the kinetic energyso during this process there is no temperature change.
22Example:Know:** Heat of Fusion, Heat of Vaporization, and Specific Heat for water can be found on Table B in your formula sheet!
Question: How many joules are required to melt 255g of ice at 0C?We know:m= 255 gHeat of fusion of water (from Table B)= 334 J/gLooking for:q= ?Looking at Table Twe have to use the formula q= mHfSo, we have to multiply the mass by heat of fusion value q= (255g)(334 J/g)Answer: 85,170 J = 85.2 kJ
***(1 J= 1000 kJ) 23Heat of VaporizationDuring boiling, liquid is turned into a gaseous vapor.Temperature is constant during this change even though energy is constantly added.Heat energy increase the potential energy of the particles in the gaseous phase.The amount of heat needed to convert a unit mass of a substance from its liquid phase to its vapor phase at constant temperature is called HEAT OF VAPORIZATIONThe Heat of Vaporization of water at 100C and 1 atmosphere is 2260 J/g.** Condensation if the reverse of the boiling process, so the heat of condensation is also 2260 J/g (exothermic).
24Example:Question: How many joules of energy are required to vaporize 423g of water at 100C and 1 atm?We Know:m= 423 gramsHeat of Fusion (from Table T)= 2260 J/gramLooking for:q= ? JoulesFrom Table T, we find we have to use q= mHvSo, we have to multiply the mass of the substance by the heat of vaporization:q= (423 grams) (2260 J/ grams)= 955,980 JAnswer: 955,980 J or 955.98 kJ
HW # 3 Review Book25Behavior of GasesKinetic molecular theory: (or KMT) is a model or theory that is used to explain the behavior of gases by describing the relationships among pressure, volume, temperature, velocity, frequency, and force of collisions.Summary of the Theory:Gases contain particles (usually molecules or atoms) that are in constant, random, straight-line motion.Gas particles collide with each other and the wall of the container. These collisions could result in the transfer of energy, but there is no net loss of energy because of these collisions. Collisions are said to be perfectly elastic ( energy is completely transferred and not lost- it is the same before and after collision)Gas particles are separated by a relatively great distance, so the volume occupied by the particles themselves is negligible and is not needed to be accounted for.Gas particles do not attract each other.
HW # 4 Review Book and Text book26Relationship by FormulaYou can figure out the relationship among pressure, temperature, and volume by using the following Combined Gas Law equation:
P1V1 = P2V2 T1 T2*For this equation, Temperature (T) has to be in Kelvin!**Any problem that does not give you a second number for one of the values, but states it is in STP- use the values on Table A for the missing values!27Ideal vs Real GasesThe Kinetic molecular theory explains the behavior of gas called an ideal gas, but solving problems in a laboratory with real gases may not have the outcome predicted using the ideal gas. Why does theory (what is predicted to happen) not always the real outcome? This is because two assumptions in the Kinetic molecular model are not perfectly correct.
28Two assumptions of the Kinetic molecular theory:Gas particles do not attract one another: although this is usually the case because attractive forces are so small, there are extreme times that these forces are important. For example: when there is extreme cold in the atmosphere, attractive forces among the molecules make the water molecules combine to form rain or snow.Gas particles do not occupy volume: although gas particles do not occupy large space under normal conditions, but when pressure increases this becomes important. At high pressure, the increased concentration of particles leads to more collisions and a greater chance of combining.
29ContinuedA gas is said to be ideal when it behaves as predicted, but most gases are not ideal. The closes gases to being ideal are Hydrogen and Helium.Gases are most ideal at low pressures and high temperatures.this is why extreme cold or high pressures are important.
30Avogadros HypothesisAvogadro stated a theory that when the volume, temperature, and pressure of two gases were the same- they contained the same number of molecules. So, 12 liters of nitrogen at STP would contain the same number of molecules as 12 liters of oxygen at STP. Today, we believe that 22.4 liters of any gas will contain one mole of that gas. We know from our previous chapters, that 6.02 X 1023 moles are in 1 mole of any substance= Avogadros Number31Separation of Mixtures: Separatory