PACKET #2 Physical Behavior of Matter Reference Table: S & Periodic Table

ENERGY: The ability to do work Chemical – released or absorbed in a chemical reaction. Electrical – energy from the flow of electricity (moving electrons) Electromagnetic Radiation – made of waves which include gamma, UV, light, radio, etc… Heat (thermal) – random motion of atoms/molecules (oil burns, chemical - > thermal) Mechanical – energy in moving objects, i.e. rock falling, car moving. Nuclear – the energy given off when a nucleus breaks down into smaller nuclei or when two nuclei are united to form a larger nucleus. Kinetic Energy: energy of movement. Potential Energy: stored energy.

LAW OF CONSERVATION OF ENERGY: Energy can’t be created or destroyed, but can only be changed from one type to another. Example: Lighting a match converts chemical energy to thermal energy (kinetic energy).

MATTER: Anything that has mass and takes up space. Matter can be classified according to: 1. Physical state of matter (solid, liquid, gas) 2. Composition (element, compound, mixture)

Physical States of Matter A. Solid: (s) -Definite Shape; Definite Volume -All the solids have a crystalline structure or regular geometric pattern -Molecules are held tightly together, vibrating in a fixed position.

Physical States of Matter Aqueous: (aq) -When a solid is completed dissolved in water

Physical States of Matter B. Liquid: (l) -NO Definite Shape; Definite Volume -Molecules are still close together, but not as close as with a solid -Particles in the liquid phase have no regular arrangement and are in constant motion, moving freely about their container

Physical States of Matter C. Gas (Vapor): (g) -NO Definite Shape; NO Definite Volume -Conform to the container they are in i.e. they are compressible -Molecules are far apart and move at very high speeds

Potential Energy (PE): Stored energy. Kinetic Energy (KE): Energy of movement. Energy is transferred from one form to another.

Temperature Defined as the average kinetic energy of a particular substance. The higher the temperature, the faster particles move, and the higher the KE is. The lower the temperature, the slower the particles move, and the lower the KE is. This is why a solid has a low KE, and a gas has the highest KE.

Heat always travels from a higher temperature to a lower temperature. The reason you feel cold in the winter is because you lose heat, not because you absorb cold (you’re warmer than the surrounding air). The reason you feel hot in the summer is because you absorb heat (the surrounding air is warmer than you).

ENTROPY A measure of the disorder of a system. The more disorder, the greater the entropy. Solids are the most organized and therefore have the lowest entropy (lowest temperature, lowest KE). Gases are the most disorganized and therefore have the highest entropy (highest temperature, highest KE).

COMPOSITION: Composition of matter can be classified into two categories: SUBSTANCES & MIXTURES

Substance Any variety of matter that has the same (constant) properties and composition throughout. A substance is always homogeneous (pure) which means that it is made up of one thing. Ex: bag of sugar.

ELEMENTS: Cannot be decomposed (broken down) into anything simpler by chemical change. Monotomic: composed of only one of the element Diatomic Molecule: two atoms of the same element bonded together (H 2, N 2, O 2, F 2, Cl 2, Br 2, I 2 ) Atom means 1 Molecule implies more than 1

COMPOUNDS: made up of two or more different elements that are chemically combined in a fixed proportion. A compound can be decomposed (broken down) by chemical means. Binary Compounds: are composed of only two elements, Ex: NaCl

Mixtures: Two or more substances that are mixed together, they are not united. Homogeneous mixtures (solutions/aqueous): considered like one thing, even though they are a mixture of two things. Example. Salt or sugar and water; the salt dissolves evenly into the water. Heterogeneous mixtures are mixtures that do not dissolve into each other like oil and water.

Techniques for Separating Mixtures 1. Filtration:  A heterogenous mixture of solid/liquid substances can be separated using this method.  The mixture is poured through a filter.  The liquid components pass through; while the solid components remain on the paper.

Techniques for Separating Mixtures 2. Magnet:  Separation on the basis of materials being influenced to different degrees by the presence of a magnetic field  Ex: Can be used to separate a mixture of iron filings & sulfur

Techniques for Separating Mixtures 3. Distillation:  Separation based on differing boiling points  A technique used to separate homogenous mixtures (solutions, aqueous) Example: Boil a solution of salt & water (water evaporates, salt is left behind). This evaporate is then typically condensed back into a liquid.

DIFFERENCE BETWEEN COMPOUNDS AND MIXTURES: Compound – chemically united Mixture – not chemically united Compound – unite in a definite ratio; proportion Mixture – can be different proportions Compound – product has different property than the elements reacting Mixture – each substance maintains its own properties.

Composition Matter Pure Substances Mixtures Compounds Elements Heterogeneous Homogeneous Binary Monotomic Diatomic H 2, N 2, O 2, F 2, Cl 2, Br 2, I 2 Filtration Magnet Distillation Solution Aqueous

Physical Properties Physical properties describe the size, shape, color, texture, flexibility, etc. of an object. Ex.—color, size, shape, density, state of matter, melting point, boiling point, volume PHYSICAL CHANGES occur when physical properties of an object are altered WITHOUT changing the chemical make up. Ex. - melting ice, boiling water

Chemical Properties Chemical properties describe a substance’s ability to form new substances; its reactivity. Key words to look our for include: react, reactivity, combust, burn, rust, oxidize. CHEMICAL CHANGES occur when a new substance(s) is made.

Identify the following as physical or chemical properties. ColorCombustibilityHardnessDensityMass Melting point Ductility Failure to react with other substances OdorWeightMalleability Tendency to corrode Volume

What are these?

Particle Diagrams Visual drawings to represent elements, compounds, or mixtures in their phases of matter. Each molecule represents an element; can create various combinations of elements, compounds, or molecules. Every particle diagram will have a key to be able to identify each individual element (atom). Element X Element Y

You must be able to answer the following questions: You must be able to answer the following questions: 1.Is the particle diagram a single substance or a mixture (more than one substance) 2.If it’s a single substance, what type? Be specific … an element (monatomic or diatomic), a compound (binary)? 3.If it’s a mixture, what is it a mixture of. Again, use the vocabulary … monatomic element, diatomic element, binary compound. 4.What phase of matter is represented? (solid, liquid, gas)

Element X = White Molecule Element Y = Black Molecule Element Z = Red Molecule X Y Z

#1: Create five (5) different types of elements. #2: Create three (3) different types of compounds.

#3: Create a mixture containing two (2) types of elements and two (2) types of compounds. #4: Create a mixture with one (1) monatomic element, one (1) diatomic molecule, and one (1) binary compound.

ENDOTHERMIC (heating) SOLID  LIQUID  GAS Solid  Liquid = melting Liquid  Gas = evaporation Solid  Gas = sublimation ***(CO 2 & I 2 )***

EXOTHERMIC (cooling) GAS  LIQUID  SOLID Gas  Liquid = condensation Liquid  Solid = freezing Gas  Solid = Deposition

Heating Curve – Endothermic (absorbing heat)

Heating Curve - Endothermic Heating curves are endothermic because the phase change goes in the direction: solid  liquid  gas Slopes represent phases. Plateaus represent phase changes. There is a temperature change at the slopes. There is no temperature change at the plateaus. Phases (slopes): KE increases; PE remains the same. Phase Changes (plateaus): KE remains the same; PE increases.

Cooling Curve – Exothermic (releasing heat)

Cooling Curve - Exothermic Cooling curves are exothermic because the phase change goes in the direction: gas  liquid  solid Slopes represent phases. Plateaus represent phase changes. There is a temperature change at the slopes. There is no temperature change at the plateaus. Phases (slopes): KE deacrease; PE remains the same. Phase Changes (plateaus): KE remains the same; PE decreases.

Energy is absorbed or released in a chemical reaction. EXOTHERMIC: energy is released (EXIT) in a chemical reaction (heat is on the right side of the reaction arrow). A+B  C + Heat (energy) ENDOTHERMIC: energy is absorbed in a chemical reaction (heat is on the left side of the reaction arrow). Heat + C  A+B Just remember... BARF (Break-Absorb, Release-Form)

Heat Equations: (Table T) Heat (q) is measured in a unit known as the Joule (SI) – everyday we use the calorie. Specific Heat Capacity: the amount of heat required to raise 1 gram of something 1 °C (ex: 4.18 joules/g°C) Change in temperature (Final - Initial) If q is negative: exothermic reaction (release heat) If q is positive: endothermic reaction (absorb heat) Heat of Fusion (energy required to freeze/melt) Heat of Vaporization (energy required to boil/condense)

Table B represents physical constants for liquid water only. If a heat equation question is asking about anything other than water, the constant for the substance will have to be provided to you. The plateau for vaporization/condensation is longer than melting/freezing because the Heat of Vaporization is always greater than the Heat of Fusion.

Practice Problems EXAMPLE: Calculate the amount of heat required to raise the temperature of 15g of water from 20˚C to 50˚C. EXAMPLE: When 20 joules of heat are added to 2g of water at 15˚C, the temperature of the water increases to?

More... Example: How much heat energy is absorbed when 10g of ice melts to form liquid water at the same temperature? Example: How much heat is absorbed when 70.0g of water is completely vaporized at its boiling point?

1. When 20.0g of a substance is completely melted at its melting point, 3444 J are absorbed. What is the heat of fusion of this substance? 2. The heat of vaporization of a liquid is 1344 J/g. What is the minimum number of joules needed to change 40.0g of the liquid to vapor at the boiling point? 3. How much energy is required to vaporize 10.00g of water at is boiling point? 4. At 1 atmosphere of pressure, 25.0g of a compound at its normal boiling point is converted to a gas by the addition of 34,400 J. What is the heat of vaporization for this compound in J/g? 5. The heat of fusion of a compound is 30.0 joules per gram. What is the number of joules of heat that must be absorbed by a 15.0g sample to change the compound from solid to liquid at its melting point?

Define energy and give some examples of forms of energy.

Define the term liquid, and explain its relative kinetic energy in comparison to a solid and a gas.

C(s) + O 2 (g)  CO 2 (g) Explain in terms of kinetic energy and particle movement whether C(s) or O 2 (g) has more entropy.

Explain what type of substances are represented in each set above. Do they represent elements, compounds, or mixtures?

Determine whether the chemical reaction below is endothermic or exothermic. Why? C(s) + O 2 (g)  CO 2 (g)

POP QUIZ!!!!

REGENT’S REVIEW QUESTIONS 1) Which substance represents a compound? A) C(s) B) CO(g) C) Co(s) D) O2(g) 2)

3) Which substance can not be decomposed by a chemical change? A)Ne B) N2O C) HF D) H2O 4)

5) Which statement describes a chemical property of iron? A) Iron can be flattened into sheets. B) Iron combines with oxygen to form rust. C) Iron conducts electricity and heat. D) Iron can be drawn into a wire. 6) Which of the following is an example of a physical change in matter? A) fizzing produced when magnesium metal is added to acid B) magnesium metal burning with a bright white flame C) melting of sodium metal D) sodium metal exploding in water

7) Consider the reaction: H 2 O (l) + energy  H 2 (g) + ½ O 2 (g). Which of the following phrases best describes this reaction? A) endothermic, releasing energy B) exothermic, releasing energy C) exothermic, absorbing energy D) endothermic, absorbing energy 8) Which phase change is endothermic? A) Fe(l)  Fe(s) B) H 2 O (l)  H 2 O (s) C) CO 2 (s)  CO 2 (g) D) NH 3 (g)  NH 3 (l)

9) Which substance can be decomposed by chemical means? A) ammonia B) oxygen C) silicon D) phosphorus 10) Which particle model diagram represents only one compound composed of elements X and Z?

11) Which of the following two substances can not be broken down by chemical change? A) C and CuO B) C and Cu C) CO 2 and Cu D) CO 2 and CuO 12) Which of the following particle diagrams represents a mixture of element X and element Z, only?

13) Which statement describes a chemical property of the element magnesium? A) Magnesium conducts electricity. B) Magnesium is malleable. C) Magnesium reacts with an acid. D) Magnesium has a high boiling point. 14) Solid ZnCl2 and liquid ZnCl2 have different A) empirical formulas B) ion ratios C) physical properties D) formula masses

15) What type of mixture is represented by X in the diagram shown? 16) What type of substance is represented by Z in the diagram shown? 17) Given a mixture of sand and water, state one process that can be used to separate water from the sand. Questions 15 through 17 refer to the following:

18) Given the balanced equation representing a reaction: CH 4 (g) + 2O 2 (g)  2H 2 O(g) + CO 2 (g) + heat Which statement is true about energy in this reaction? A) The reaction is exothermic because it releases heat. B) The reaction is endothermic because it releases heat. C) The reaction is endothermic because it absorbs heat. D) The reaction is exothermic because it absorbs heat.

19) Given the balanced equation representing a reaction: Cu + S  CuS + energy Which statement explains why the energy term is written to the right of the arrow? A) The compound CuS is composed of two metals. B) Energy is released as the bonds in CuS form. C) The compound CuS is composed of two nonmetals. D) Energy is absorbed as the bonds in CuS form. 20) At which temperature would atoms of a He(g) sample have the greatest average kinetic energy? A) 25°C B) 273 K C) 298 K D) 37°C 21) Which Kelvin temperature is equal to 56°C? A) -217 K B) 329 K C) 217 K D) -329 K

22) A temperature of 37°C is equivalent to a temperature of A) 310. K B) 98.6 K C) 371 K D) 236 K 23) At which Celsius temperature does lead change from a solid to a liquid? A) 874°C B) 0°C C) 328°C D) 601°C 24) What term refers to the difference between the potential energy of the products and the potential energy of the reactants for any chemical change? A) heat of fusion B) heat of reaction C) heat of deposition D) heat of vaporization

25) A 5.00 gram sample of water is heated and the temperature rises from 10.0°C to 15.0°C. What is the total amount of heat energy absorbed by the water? A) 84 J B) 42.0 J C) 105 J D) 21.0 J 26) What is the total number of joules of heat energy released when 20.0 grams of water is cooled from 20.0°C to 10.0°C? A) 836 J B) 200. J C) 30.0 J D) 83.6 J 27) If 4.0 grams of water at 1.0°C absorbs 33 joules of heat, what will be the change in temperature of the water? A) 3.0°C B) 4.0°C C) 2.0°C D) 1.0°C

28) What is the total number of joules released when a 5.00-gram sample of water changes from liquid to solid at 0°C? A) 1,670 J B) 2,260 J C) 334 J D) 11,300 J 29) A hot pack contains chemicals that can be activated to produce heat. A cold pack contains chemicals that feel cold when activated. Based on energy flow, state the type of chemical change that occurs in a hot pack.

30) The graph below represents the uniform heating of a substance, starting below its melting point, when the substance is solid. Which line segments represent an increase in average kinetic energy? A) AB and BC B) AB and CD C) DE and EF D) BC and DE

31) Given the heating curve where substance X starts as a solid below its melting point and is heated uniformly: Identify the process that takes place during line segment DE of the heating curve shown.

32) The graph below represents the uniform heating of a substance, starting with the substance as a solid below its melting point. Which line segment represents an increase in potential energy and no change in average kinetic energy? A) CD B) EF C) BC D) AB