Accelerated Chemistry Study Guide Energy and Matter (Chapter 2)

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1 Accelerated Chemistry Study Guide Energy and Matter (Chapter 2) Matter 2-3 States of Matter (Figure 2-12) Properties of Matter Changes in Matter o Physical changes o Chemical changes Conservation of Matter September 2017 Page 1 of 39

2 Elements and Compounds 2-4 Elements Compounds Pure substances Mixtures 2-5 Types of mixtures Separating the components of a mixture September 2017 Page 2 of 39

3 Energy 2-1 Forms of energy Measuring Energy Law of Conservation of Energy Temperature 2-2 Temperature Scales, converting between different scales September 2017 Page 3 of 39

4 The World of Chemistry Episode 5 - A Matter of State 1. The video states that states of matter may be changed. What is needed to make this possible? 2. What is the relationship between the temperature and pressure of a gas? 3. Describe, at the molecular level, how temperature affects the pressure of a gas. 4. How does the collapsing can demo work. Draw diagrams of before, during, and after the heating. 5. How is liquefied natural gas produced? 6. What are some uses of liquid nitrogen? 7. Why does the process of perspiration cool a person? 8. Describe the element bromine in its three states. 9. What happens to the particles in bromine as it is cooled? 10. What does the shape of a crystal tell us about its internal structure? September 2017 Page 4 of 39

5 States of Matter Matter consists of tiny particles called atoms and molecules. In a solid, these particles shiver about fixed positions. This is why solids have a fixed shape and fixed volume. In a liquid these particles slide over each other and can move in all directions, but always stay in contact with one another. This is why liquids have no fixed shape, but DO have a fixed volume. In a gas, these particles are free to move in all directions. They collide with each other and with the sides of the container. This is why gases expand to fill any container (they don t have a fixed volume or a fixed shape.) Classification of matter: Matter can be subdivided in the following way: Matter Pure Substances Mixtures Element Compound Heterogeneous Mixture Homogeneous Mixture Elements are the building block of nature. They cannot be further subdivided. There are 112+ of them on the periodic table. A sample of pure neon (Ne) would contain only neon atoms (atomic element). A sample of pure oxygen (O 2 ) would contain only oxygen molecules (molecular element). Another example of a molecular element is carbon (diamond, graphite, buckminsterfullerene). Compounds are pure substances that are composed of two or more elements chemically bonded together. CO 2 (carbon dioxide), H 2 O (water), and C 6 H 12 O 6 (glucose) are all examples of compounds. Compounds can only be subdivided into elements by a chemical process. Heterogeneous mixtures contain regions that have different properties from those of other regions. We call these regions phases, and in a heterogeneous mixture, the phases are not uniformly distributed. For example oil and water, when mixed together, quickly separate into an oil phase and a water phase floating September 2017 Page 5 of 39

6 on top of one another. A mixture of sugar and sand is also not uniformly distributed. Milk is a heterogeneous mixture because if it is examined with a microscope, one finds that it is not uniformly distributed--there are tiny oil droplets suspended in another phase, which is mostly water. Homogeneous mixtures are uniformly distributed. Salt water and air are both examples of homogeneous mixtures because they consist of several compounds mixed together uniformly. Solution is synonymous with homogeneous mixture. Though we will most commonly refer only to liquid solutions, gaseous solutions (like air) and solid solutions (called alloys) exist. Alloys of metal (like brass--a mixture of Cu and Zn, or 14 carat gold, a mixture of gold, silver, and copper) are solid elements that are mixed together uniformly. Both heterogeneous mixtures and homogeneous mixtures can be separated into the compounds of which they are composed by physical processes such as filtration or distillation. Physical and Chemical changes Physical Changes do not affect the composition of a substance. In other words, they are physically reversible, leaving the molecules or atoms involved in the change intact but in another form. Examples that convert matter from one state to another are freezing, melting, boiling, condensing, sublimation and evaporation. Other examples are dissolving, breaking, or stretching. Chemical changes convert pure substances into different substances. Chemical changes cannot be undone by any physical change. Two examples are electrolysis of water: 2H 2 O (l) 2H 2 (g) + O 2 (g) and the burning of magnesium in oxygen: 2Mg (s) + O 2 (g) 2 MgO (s) Physical and Chemical Properties Physical properties correspond to physical changes so boiling point, freezing point, and solubility (how much will dissolve) are all physical properties. Any property that can be observed without changing the substance is a physical property, so odor, color, magnetic properties, are physical properties. Chemical properties require that a substance undergo a chemical change in order to observe them. Examples are flammability, acidity, basicity, reactivity, and oxidation potential. September 2017 Page 6 of 39

7 Chapter 2 notes and practice problems Physical and Chemical changes Physical Changes do not affect the composition of a substance. In other words, they are physically reversible, leaving the molecules or atoms involved in the change intact but in another form. Here are six fundamental physical changes (s=solid, l=liquid, g=gas): ENDOTHERMIC (require energy) melting (s l) boiling (l g) sublimation (s g) EXOTHERMIC (release energy) freezing(l s) condensation(g l) deposition(g s) Other examples of physical changes are dissolving, breaking, or stretching. Chemical Changes do affect the composition of a substance. In a chemical change, a new substance is created! Practice Problems 1. Define Element Compound homogeneous mixture heterogeneous mixture Use the four terms below to answer questions 2-6 A. element B. compound C. homogeneous mixture D. heterogeneous mixture 2. Which of the above consists of atoms of a single type? 3. Which two of the above can be separated into pure substances by physical means? 4. Which of the above can be separated into simpler substances only by chemical means? 5. Which two of the above are pure substances? 6. Which of the above is a solution? September 2017 Page 7 of 39

8 7. True or False: A solution is always a solid dissolved in a liquid. 8. Describe electrolysis and distillation. Which is used to separate salt water into its components (salt and water)? Which is used to separate pure water into its elemental components (hydrogen and oxygen)? Electrolysis: Distillation: Tell whether each of the following is an element, compound, homogeneous mixture, or heterogeneous mixture. 9. table salt (NaCl or sodium chloride) 10. carbon dioxide gas (CO 2 (g)) 11. platinum metal (Pt) 12. gold 13. salad dressing 14. lime Jell-O 15. butter 16. air Classify each of the following as a chemical change or physical change 17. Melting gold 18. Heating iron in the presence of carbon to change it to steel 19. Dissolving salt in water 20. Distilling water 21. Subjecting water to hydrolysis 22. CO 2 (s) CO 2 (g) Also, name this process. 23. CH 4 (g) + 2 O 2 (g) 2 H 2 O (l) + CO 2 (g) Do you know the name of this process? Classify each of the following as a chemical property or a physical property 22. Flammability 23. Reactivity 24. Solubility (ability to dissolve) 25. Melting point 26. Density September 2017 Page 8 of 39

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10 ChemQuest 3 Name: Date: Hour: Information: Changes in Matter Books are made of matter. You are made of matter. Matter is a fancy word for the stuff of which all objects are made. Every day, matter is changed in different ways. For example, paper can be changed in many ways it can be torn, folded, or burned. A chemical change is any alteration that changes the identity of matter. For example, by passing electricity through water it can be broken down into hydrogen and oxygen. Burning paper is a chemical change because after the change takes place, the paper has been changed into different substances (like ash, carbon dioxide, etc.). A physical change is any alteration that does not change the identity of the matter. Shredding paper does not change the paper into a different substance. Dissolving salt in water is a physical change because after the change, the salt and water are both still there. Critical Thinking Questions 1. Explain why each of the following is a physical change. a) boiling water until no water remains b) mixing sugar with coffee 2. Explain why each of the following is a chemical change. a) a car rusting b) food digesting 3. Identify each of the following changes as chemical or physical by placing a C or P in each blank. a) acid rain corroding the statue of liberty b) dissolving salt in water c) boiling salt water until just salt remains d) melting steel e) dissolving steel in acid f) cracking ice September 2017 Page 10 of 39

11 Information: Elements, Compounds, Mixtures Examine the following tables. Following the name of each element or compound is the chemical formula of the element or compound; please see the periodic table for the meaning of some of the symbols (i.e. Na = sodium). Italics tell you that substance is organic. Critical Thinking Questions Elements Compounds Sodium (Na) Water (H 2 O) Chlorine (Cl) Methane (CH 4 ) Carbon (C) Sodium chloride, salt (NaCl) Oxygen (O) Carbon dioxide (CO 2 ) Hydrogen (H) Hydrogen Peroxide (H 2 O 2 ) Pure Substances Mixtures Salt (NaCl) Salt water (NaCl and H 2 O) Hydrogen (H) Sand Carbon dioxide (CO 2 ) Hydrogen (H) and Oxygen (O) Water (H 2 O) Sodium (Na) and Chlorine (Cl) Aluminum (Al) Kool-aid (sugar, water, etc.) 4. How are elements different from compounds? 5. How are compounds different from mixtures? 6. How are pure substances different from mixtures? 7. Can something be both a mixture and a pure substance? Explain using examples from the tables. 8. Is it always possible to identify something as an element, compound, pure substance or mixture just by looking at it? Explain using examples from the tables. September 2017 Page 11 of 39

12 9. Formulate a definition for each of the following terms. a) element: b) compound: c) mixture: d) pure substance: 10. Categorize each of the following as an element, compound, mixture, or pure substance. If more than one label applies, then include both labels. (You will need more than one label sometimes.) a) Popsicle c) Gold b) Sugar d) Dishwater 11. If you have a container with hydrogen gas and oxygen gas in it do you have water? Why or why not? 12. Give an example of something that is an element. Your example should not already be on this sheet. 13. Give an example of something that is a compound. Your example should not already be on this sheet. 14. Give an example of something that is a mixture. Your example should not already be on this sheet. 15. What do all organic substances have in common? September 2017 Page 12 of 39

13 Information: Homogeneous and Heterogeneous Mixtures Examine the following table. Example of Mixture # of phases in mixture How many kinds of states in mixture Homogeneous or heterogeneous? Salt water 1 2 Homogeneous Oil and water 2 1 Heterogeneous Sugar and salt (no water) 2 1 Heterogeneous Sugar and salt in water 1 2 Homogeneous Sand and water 2 2 Heterogeneous Carbon dioxide, water, and ice 3 3 Heterogeneous 14 kt. gold (mixture of silver and gold) 1 1 Homogeneous Critical Thinking Questions 16. What is the difference between a "phase of matter" and a "state of matter"? Define each term as best you can. 17. What relationship exists between a homogeneous mixture and the number of phases in the mixture? 18. What is the difference between homogeneous and heterogeneous mixtures? 19. If you had to categorize elements as homogeneous or heterogeneous, what category would you put them in? 20. If you had to categorize compounds as homogeneous or heterogeneous, what category would you put them in? 21. Categorize each of the following as homogeneous or heterogeneous. a) salad c) dishwater b) ice water d) 14 kt. Gold September 2017 Page 13 of 39

14 Skill Practice 3 Name: Date: Hour: 1. Explain why compounds are always homogeneous, but mixtures can be either homogeneous or heterogeneous. 2. A white powder is in a beaker. Which statement(s) can be said for sure about the powder? I. It is homogeneous II. It is heterogeneous III. It is a mixture. IV. It is a compound. A) I only B) I and IV only C) I and III only D) III only E) none of these 3. Classify the following as chemical changes (C) or physical changes (P). Place a C or P in the blanks as appropriate. d) melting steel a) a dead fish rotting e) bending steel b) dissolving salt in water f) cracking ice c) boiling salt water until just salt remains 4. Identify the following as an element (E), compound (C), or mixture (M). a) calcium b) calcium and oxygen in the same container c) calcium and oxygen atoms bonded d) water e) sodium f) sand 5. How many phases and how many states are in a mixture made out of sand, saltwater, oil and ice. September 2017 Page 14 of 39

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Accelerated Chemistry: Chapters 1& &2 Practice

78 The density column consists of layers of liquids

other, and which are clearly distinguishable from

The highest density material is at the bottom of

density of each successive layer decreases, with

Use the information in the table to predict the

Rubbing Alcohol Vegetable Oil Water Dawn Dish Soap

21 Accelerated Chemistry: Chapters 1& &2 Practice Problems A density column is a common science demonstration. Using several household liquids we are able to create a wonderful liquid rainbow. Material Lamp Oil Density (g/cmm 3 ) 0.78 The density column consists of layers of liquids of different densities which do not mix with each other, and which are clearly distinguishable from each other. The highest density material is at the bottom of the column, and as you proceed up the column, the density of each successive layer decreases, with the lowest density layer on top. 1. Use the information in the table to predict the density of rubbing alcohol. Rubbing Alcohol Vegetable Oil Water Dawn Dish Soap Lightt Corn Syrup Honey The picture to the right is a Density Column. On the picture draw an ice cube in its appropriate location. (The density of ice is g/cm 3.) September 2017 Page 21 of 39

22 Refer to the table on the previous page for density information where necessary. 3. The nutrition label for honey has been provided to the right. Based on the serving size listed determine the number of Tablespoons of honey the label is describing. (15 ml = 1 tablespoon) 4. Based on the label determine how many Joules are the equivalent to 2 teaspoons of honey are used to flavor your morning tea. (5 ml = 1 teaspoon) 5. Lamp oil is nothing more than refined kerosene with coloring and fragrance added. It s heat of combustion is 43.1 MJ/kg. If we have a lamp that holds 14.3 cm * 4.54 cm * 3.7 cm, how many calories are produced if all the oil in the lamp is burned? 6. If the energy from the oil lamp was used to heat 50 kg of water that is intially at 32 o C, calculate the final temperature of the water in Kelvin. September 2017 Page 22 of 39

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34 Name Date Accelerated Chemistry Chapters 1-2 Practice Test 77 points I. Multiple Choice (2 points Each). Identify the letter of the choice that best completes the statement or answers the question. 1. Which of the following is a prefix that makes the unit larger? a. kilo- c. millib. deci- d. pico- 2. A milliliter is the same volume as a a. cubic centimeter. c. centimeter. b. millimeter. d. cubic meter. 3. In which of the following is the zero not significant? a c b d What kind of energy is carried by objects in motion? a. kinetic energy c. radiant energy b. electrical energy d. potential energy 5. Which state of matter is characterized by definite shape and definite volume? a. plasma c. solid b. liquid d. gas 6. Which of the following is a physical property? a. flammability c. tendency to rust b. density d. none of the above 7. Which of the following describes what happens when a gas is transformed into a liquid? a. freezing c. vaporization b. sublimation d. condensation 8. Which of the following techniques cannot be used to separate homogeneous mixtures? a. distillation c. chromatography b. crystallization d. filtration September 2017 Page 34 of 39 Page 1 of 6.

35 Name Date Figure How should the mercury level shown on the Celsius thermometer in Figure 2-2 be labeled? a. 100 c. 273 b. 212 d If the thermometers in Figure 2-2 were immersed in an ice-water bath, what should the mercury level on the Kelvin scale be labeled? a. 273 c. 32 b. 0 d. 273 Page 2 of 6. September 2017 Page 35 of 39

36 Name Date Figure What does the Sample 2 in Figure 2-3 illustrate? a. a gas. c. plasma. b. a solid. d. a liquid. 12. Which sample in Figure 2-3 shows a compound? a. sample 1 only c. sample 3 only b. sample 2 only d. none of the samples 13. Which sample in Figure 2-3 shows only an element? a. sample 1 only c. sample 3 only b. sample 2 only d. none of the samples 14. Which sample in Figure 2-3 shows a mixture? a. sample 1 only c. sample 3 only b. sample 2 only d. none of the samples 15. In which of the samples shown in Figure 2-3 is the density high? a. sample 1 only c. samples 1 and 3 b. sample 2 only d. samples 2 and 3 September 2017 Page 36 of 39 Page 3 of 6.

37 Name Date Figure Which process in Figure 2-4 illustrates a chemical change? a. process 1 only c. process 3 only b. process 2 only d. processes 1 and Which process in Figure 2-4 illustrates a change of state? a. process 1 only c. process 3 only b. process 2 only d. processes 1 and 3 II. Free response. Answer the question in the space provided. Remember to show your work. Remember significant figures. 18. A student measures the mass of an object as g. Calculate the percent error in the measurement, given that the accepted value for the mass is g. (5 points) Page 4 of 6. September 2017 Page 37 of 39

38 Name Date 19. Find the volume in milliliters of an object with a density of 0.76 g/cm 3 and a mass of mg. (6 points) 20. A mass of water at a temperature of 285K was exposed to 3.46 kilojoules of heat, resulting in a temperature increase to 85.0 C. What was the mass of the water? (8 points) 21. Draw a particle-level diagram of a mixture of a piece of steel (den = 7.85 g/cm 3 ), liquid mercury (den = 13.5 g/cm 3 ), salt water (NaCl dissolved in water, den = 1.12 g/cm 3 ), and carbon dioxide gas (den = g/cm 3 ) in a sealed container. (10 points) How many states are present? How many phases? September 2017 Page 38 of 39 Page 5 of 6.

39 Name Date 22. Identify each of the underlined phrases in the following account of a laboratory procedure as either a chemical change (C) or a physical change (P). Explain your answers. (1 point each for C or P, 1 point each for explanation, total 14 points) The unknown substance was tested to determine its properties. First, a sample was ground up finely with a mortar and pestle. Next, samples were dissolved in water and other solvents. A Bunsen burner was lighted and some of the pure chemical was placed into a test tube and heated gently until it melted. Because the heating was too rapid, the test tube cracked and the experiment was repeated. Heating was continued this time until the substance boiled. Some fumes of the boiling substance reacted with oxygen in the air to form a white powder. sample was ground up finely: samples were dissolved in water: A Bunsen burner was lighted: it melted: the test tube cracked: the substance boiled: fumes of the boiling substance reacted with oxygen in the air: Page 6 of 6. September 2017 Page 39 of 39

Honors Chemistry Chapter 2 Problem Handout Solve the following on separate sheets of paper. Where appropriate, show all work. 1. Convert each of the

Honors Chemistry Chapter 2 Problem Handout Solve the following on separate sheets of paper. Where appropriate, show all work. 1. Convert each of the following quantities to the required unit. a. 12.75