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Bill Nye Discovery Video Atoms in an aluminum can Properties of MatterProperties Temperature Misconceptions (Heat Capacity)Temperature Misconceptions.

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Presentation on theme: "Bill Nye Discovery Video Atoms in an aluminum can Properties of MatterProperties Temperature Misconceptions (Heat Capacity)Temperature Misconceptions."— Presentation transcript:

1 Bill Nye Discovery Video Atoms in an aluminum can Properties of MatterProperties Temperature Misconceptions (Heat Capacity)Temperature Misconceptions

2 Matter and Energy

3 I. What is matter? Matter can be defined as anything that ____ _____________________. Therefore, all matter has a _____ and a ______. The building blocks of matter are atoms and molecules. An atom is _________________________ ____________________________________. An element is a _____________________ __________________. → Cannot be ___________; simplest form of matter Give three examples of elements: has mass and takes up space mass volume the smallest unit of an element that maintains the properties of that element pure substance made of only one kind of atom broken down

4 A compound is a substance that is made from ___________________________________ _______________. Give three examples of compounds: A molecule is the ________________________ __________________________________ _____________________. the atoms of two or more elements that are chemically bonded smallest unit of an element or compound that retains all the properties of that element or compound

5 A. Describing Matter 1. Extensive Property – a property that depends on the ______ of matter in a sample. Examples: 2. Intensive Property – a property that depends on the ____ of matter in a sample, not the amount of matter. Examples: To identify an unknown substance, ______________ are examined. amount mass, volume type melting point, density many properties

6 Properties can be divided into two groups: a. physical property- ________________ _________________________________ _________________ Examples: → A physical change ________________ _____________________________ ____________________ Examples: Check out Table S! a characteristic that can be observed or measured without changing the identity of the substance. boiling point, malleability, texture is a change in a substance that does not change the identity of the substance. cutting, melting, boiling

7 Properties can be divided into two groups: b. chemical property- relates to a substances ability to ______________ that will transform it into _______________. Examples: ability of charcoal to _____, the ability of iron to ____. → A chemical change is a change in which ___________________ are converted into _________________. Examples: charcoal burning -charcoal (carbon) plus oxygen yields carbon dioxide. undergo changes another substance burn rust one or more substances different substances

8 * Chemical changes are often written as ________, with the _________ (undergoing the change) and ________ (substances formed) clearly identified: reactions reactants products carbon + oxygencarbon dioxide (reactants)(product)

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10 B. Classification of Matter Pure Substance- Element or _________; Composition is ______________ sample. Mixture- A __________________________ ________; → a homogeneous mixture is ________ ________________; also called a _______. Example: → a heterogeneous mixture is _____ _______ throughout sample; Example: compound same throughout physical blend of more than one substance uniform throughout sample solution NOT uniform salt water Ice Cream Blizzard

11 1. Separating Mixtures - based on differences in physical properties ( ) Filtration – separates a ________________ in a _____________ mixture. Ex. Brewed coffee Distillation – used to separate a mixture of _________ based on their ____________ ______. density, boiling point, melting point solid from the liquid heterogeneous two liquids different boiling points

12 Checkpoint What is the difference between an element and a compound? __________________________________________________________ How many different elements are in a water molecule? ______ A molecule of carbon dioxide? _______ How do physical properties and chemical properties differ? __________________________________________________________ Classify each as a physical change(P) or a chemical change (C): ripping a sheet of paper _____ melting a piece of wax ____ burning a log _____ Identify the following as a homogeneous mixture, a heterogeneous mixture, or a pure substance: Sand on a beach __________ iodine ________________ Apple juice _____________ chicken noodle soup ___________ Separating Mixtures Activity

13 Unit 2- Part 2:The Flow of Energy Law of Conservation of Energy – _____ ___________________________________ ________________________ → Energy can only change forms. I. Heat and Temperature Thermochemistry is the study of the _______ ____________ that accompany chemical reactions or physical changes. Temperature is a measure of the _________ ____________ of the particles in a sample of matter. in any chemical or physical process, energy is neither created nor destroyed. changes in heat energy average kinetic energy

14 → The greater the avg. kinetic energy, the ___________________. * Absolute Zero - point at which all molecular motion stops; has never been reached! UnitFahrenheitCelsiusKelvin SymbolºFºCK Conversion(9/5)ºC Freezing Point of Water Boiling Point of Water Body Temperature Room Temperature~ Absolute Zero* greater the temperature ºC

15 Convert the following: a.98.6 ºF to ºC b. 84ºC to K c. -5.6ºC to ºF d. 210ºF to K

16 A. The ability to measure temperature is based on __________. * Heat (q) is the sum total of the ______ _______ of the particles in a sample of matter, and measured in ______ (or kJ). Heat always flows from areas of _______________, to areas of ______________. Example: If a hot brass bar is placed in a room-temperature glass of water, the heat will flow from __________, to ________, until both are ________ __________. heat transfer kinetic energies Joules high concentration low concentration the brass bar the water the same temperature

17 What is the flow of energy when an ice cube is placed in a warm glass of water? A calorie (cal) is the _____________ needed to raise the temperature of _________________. → How many calories are needed to raise one gram of water 8°C? → How many calories are needed to raise two grams of water 4°C? quantity of heat 1 gram of water 1°C

18 The quantity of heat being transferred depends on three things: 1. The ______ of the material changing temperature. - _____ conducts heat much better than ______. ● The specific heat of a substance is the ___________________________________ ________________. Using your reference tables, what is the unit for specific heat? SubstanceSpecific Heat ( ) water (l)4.18 ethanol (l)2.44 calcium (s)0.647 gold (s)0.129 nature metal plastic amount of heat needed to raise one gram of the substance 1°C

19 ☼ Heat affects the temperature of objects with _______________ much less than the temperature of those with _______________. 2. The _____ of the material changing temperature. - It takes more heat to increase the temperature of a ______ block than it does to increase the temperature of a _____ block. 3. The ____ of the temperature change. - _________ is needed to change the temperature of a liter of water 8°C than to change a liter of water 1°C. high specific heat low specific heat mass 10cm 3 1cm 3 size More heat

20 Combining these three factors, the amount of heat (q) gained or lost with a change in temperature of a substance can be found using the following equation: q= q = mC Δ T m= C= Δ T= heat released or absorbed (Joules) mass of substance (grams) specific heat capacity (J/g●°C) change in temperature (°C)

21 The temperature of a 85.0 gram piece of copper alloy increases from 30.0°C to 45.0°C when the copper absorbs 523 J of heat. What is the specific heat of the copper alloy? How much heat will the same sample lose if it is cooled to 25 °C? 0.41 J/(gK) 697 J

22 What is the total number of Joules of heat energy absorbed by 15 grams of water when it is heated from 30 °C to 40 °C? How many Joules of heat energy are released with 50 grams of water is cooled from 70 °C to 60 °C? → How many calories are released in the above example?

23 II. States of Matter Change of state- a ______________ of a substance from one state of matter to another. The three states of matter are indicated on the chart below: StateCharacteristicExample ShapeVolumeMolecular Arrangement Solid (s) Liquid (l) Gas (g) physical change definite indefinite Close together; fixed Close together; flow Far apart; flow iron water neon

24 The arrangement of molecules can be seen in the diagram below: A. Although it may be difficult to imagine, the molecules in each state are in constant motion. What happens when a drop of food color is placed on one side of a cup of water? In which state do you think particles are moving the fastest? The slowest?

25 Compare the molecules in each state of matter: SolidLiquidGas Speed of particles Avg. KE of particles Attraction among particles Entropy (randomness) Low Energy High Energy

26 What happens when you add heat energy to solid water (ice)? What happens when you add heat energy to liquid water? Therefore, as ______________ to the different states of matter, they are able to _______ _____________________. As heat is added, the molecules become so ________, that they overcome the _____________ holding them together. It melts into a liquid It vaporizes into steam energy is added change into a new state of matter energetic attractive forces

27 Possible changes of state are shown below: Which terms are opposites? -

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29 B. Heats of Vaporization and Fusion 1. Heat of Vaporization (Hv) – the heat necessary to convert a given amount of a _____________ _______ It takes 40.7 kJ to vaporize 18 grams of water (2260 J/g) How many kJ does it take to condense 18g of water? → Exactly the same as the quantity of heat ________ when the vapor condenses (-ΔHcond). liquid into a gas (vapor). released

30 Vaporization and condensation occur at the same __________!! a.Determining heat needed to vaporize/condense a specific amount of liquid/gas → q = mHv temperature

31 How much heat is absorbed when 24.8 g of H2O(l) at 100°C and kPa is converted to steam at 100°C? How many kilojoules of heat are absorbed when 0.46 g of chloroethane (C 2 H 5 Cl) vaporizes at its normal boiling point? (Hvap = 26.4 kJ/mol)

32 2. Heat of Fusion (Hf) – the heat necessary to convert a given amount of a ____________________. It takes 6.0 kJ to melt 18 grams of solid water (334 J/g). How many kJ does it take to freeze 18g of water? → Exactly the same as the quantity of heat is released when the liquid solidifies (-ΔHsolid) Fusion and melting occur at the same __________!! a. Determining heat needed to melt/freeze a specific amount of solid/liquid → q = mHf solid into a liquid temperature

33 How many grams of ice at 0 ° C will melt if 2.25 kJ of heat are added? How many grams of ice at 0°C could be melted by the addition of kJ of heat?

34 If heat is being added, why is the temperature constant? The energy is being used to ____________ _____________. Substances with high ____________ and ___________ have high __________________. overcome the attractive forces melting points boiling points intermolecular forces

35  Checkpoint What formula would you use if there is a change in temperature? _________________ Which state of matter has the strongest intermolecular forces? _________________ What formula would you use to determine how much energy it takes to convert a solid to a liquid? _______________________ From a gas to a liquid? ___________________ Does it take more energy to turn ice into liquid water or to turn liquid water into water vapor? Explain _____________________ Why do substances with strong intermolecular forces have higher melting and boiling points? _______________________

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