analyze and assimilate terminology used to describe matter and properties

1. Chapter 3: Data Analysis Objectives: the student will be able to: analyze and assimilate terminology used to describe matter and properties compare and contrast properties of the various states of matter; assess when a change is physical or chemical compare and contrast pure substances to all types of mixtures distinguish between elements and compounds; dissect a chemical formula express chemical information in terms of chemical formulas

2. What Are The Three States of Matter? How are they similar? How are they different?

3. Atoms: Smallest particle of matter that is recognizable as a specific element. Element: A pure substance that can not be broken down into simpler substances by physical or chemical means. Compound: A pure substance that is the chemical combination of two or more atoms. Can be broken down into simpler substances by chemical means. Pure Substance: form of matter that has an unchanging composition throughout. Can be an element or a compound. Examples: Silver Water Sugar Diamond Oxygen Which category or categories does each of these materials belong?

4. Examples Cu Al I2 Hg Fe S

5. Two Major ways of classifying Matter: Homogeneous mixture: mixture that has a uniform composition throughout-a single phase. Also called a solution. Heterogeneous mixture: mixture that is not uniform throughout-different substances or phases can be “seen”. Examples: Orange Kool-Aid Ice and Water Salt and Pepper 14 k Gold Chocolate Chip Cookie Salt Water Smoke Boiled Egg

6. Properties of Matter: Physical or Chemical Physical: properties that can be observed without changing the material into another substance. Chemical: properties relate to the ability of a material to change into another substance. Examples: Lead is dense. Melting point of water is 0oC P C P C P P C P Cobalt sulfate is blue. Sodium will react with water. Steel is hard. Charcoal will burn. Iron will rust. Boiling point of gold is 2000oC Classify each property as Physical (P) or Chemical (C)

7. Intensive versus Extensive Property Intensive: property that is independent of the amount of matter present. Extensive: property that depends upon the amount of matter present. Examples: Boiling Point Mass Density I E I E E I Volume Temperature Heat Classify each property as Intensive (I) or Extensive (E)

8. Changes in Matter: Physical and Chemical Physical: change that occurs without changing the substance into a different substance. Chemical: change that occurs when one substance is changed into another substance. Examples: gold is melting a candle is burning an egg is frying P P C P C C breaking a glass water is evaporating iron is rusting Classify each change as Physical (P) or Chemical (C)

9. Solid Na + Gaseous Cl2→ Solid NaCl (salt) The properties of a substance are different from the elements that make it up!

10. Law of Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction. Therefore in a chemical reaction, Mass (reactants) = Mass (products) Example: 2 HgO (s) → 2 Hg (l) + O2 (g) If 216.0 g of HgO are used, and 200.0 g of Hg are made, how many grams of O2 must have been made? 216.0 g = 200.0 g + x g x g = 216 g – 200.0 g = 16.0 g of O2 made Make special note of all problems! Expect to have to do this on a quiz or test!

11. Physical methods of separation means that no chemical changes are occurring. This means that no chemical is becoming a different chemical during the process. Some examples of physical methods of separation include: Distillation Filtration Crystallization Chromatography

12. Distillation: separates compounds based upon the boiling point of each compound present.

13. Chromatography: Separation of compounds based on affinity for solvents and solid support materials. A Line of the Mixture to be Separated is Placed at One End of a Sheet (paper in this example) The Paper Acts as a Wick to Draw up the Liquid (the solvent) Component with the Weakest Attraction for the Paper (the solid support in this example) Travels Faster In the picture, which color had the greatest affinity for the paper? The least?

14. Law of Definite Proportions Regardless of amount (or source), a compound is always composed of the same elements in the same proportions by mass. In contrast: if two substances have different proportions by mass, they must be different compounds. For example: Water is 11.19% hydrogen and 88.81% oxygen by mass no matter where the water comes from. Hydrogen Peroxide is 5.93% hydrogen and 94.07% oxygen by mass. Both compounds only contain H and O One compound is essential for life, the other is toxic! Water is H2O and Hydrogen Peroxide is H2O2

15. Percent by Mass (or Mass Percent) Mass of Element x 100 Mass % = Mass of Compound Example: If a 5.00 g sample of sodium chloride (NaCl) is found to contain 1.97 g of sodium and 3.03 g of chlorine, what is the mass % of sodium in NaCl? What is the mass % of chlorine in NaCl? (1.97 g Na/5.00 g NaCl) X 100 = 39.4% Na (3.03 g Cl/5.00 g NaCl) X 100 = 60.6% Cl Make special note of all problems! Expect to have to do this on a quiz or test!

16. Law of Multiple Proportions: Mass Ratio %Cu/%Cl % Cu % Cl 64.20% 35.80% 42.27% 52.73% Compound I Compound II 64.20/35.80 = 1.793 42.27/52.73 = 0.8964 Meaning of Mass Ratios 1.793/0.8964 = 2.000 1.793 g Cu to 1.000 g Cl 0.8964 g Cu to 1.000 g Cl The Law of multiple proportions states that the ratio of the above mass ratios must be a small whole number. This is important because it indicates that if two compounds have only copper and chlorine in them, they must have different formulas. In the example above, Compound II has twice as many chlorine atoms as Compound I.

17. Law of Multiple Proportions: Mass Ratio %O/%H % H % O 11.19% 88.81% 5.93% 94.07% Water Peroxide 88.81/11.19 = 7.937 94.07/5.93 = 15.9 Meaning of Mass Ratios 15.9/7.937 = 2.00 7.937 g O to 1.000 g H 15.9 g O to 1.000 g H It turns out that one compound has twice as much oxygen per hydrogen as the other compound. H2O and H2O2 Note: the law of multiple proportions did not tell us the number of H atoms compared to O atoms in water! We know this from other data.

18. Law of Conservation of Mass Practice N2 (g) + 3 H2 (g) → 2 NH3 (g) 1) If 28.0 g of N2 react exactly with 6.0 g of H2, how many grams of NH3 are produced? 2) If 53.5 g of NH3 are produced by the reaction of 42.42 g of N2 with excess H2, how many grams of are H2 consumed? 2 NH3 (g) → N2 (g) + 3 H2 (g) 3) If 128.4 g of NH3 are reacted to produce 98.4 g of N2, how many grams of are H2 produced?

19. Mass % Practice 1) If 28.0 g of a sample of compound are found to contain 8.00 g of calcium and 20.00 g of iodine, what is the mass % of calcium in the sample? What is the mass % of iodine in the sample? 2) If a compound is known to be 22.00% carbon and 78.00% chlorine by mass, how many grams of carbon would there be in 3.721 g of the compound? How many grams of chlorine?

20. Classification Practice 1) Classify each of the following as a mixture or as a pure substance. 2) For each one that is a pure substance, identify it as an element or a compound. Water Blood Ocean Water Iron Brass Uranium Draft Beer Salt (NaCl) 3) For each one that is a mixture, identify it as a heterogeneous or homogeneous mixture.

21. Classification Practice 1) Classify each of the following as a physical or chemical change. • Moth balls gradually evaporate in a closet. • Hydrofluoric acid attacks glass and is used to etch markings in glass equipment. • A French chef burns off the alcohol in brandy to leave the brandy flavor behind. • Chemistry students sometimes get holes in cotton clothes because of acid spills. • A block of wax melts when heated with boiling water. • A student cuts aluminum foil into small pieces. • A crystal vase breaks when it falls on the floor. • An acidic solution turns pink when enough base is added.

22. Other related math skills practice. 1) A single antibiotic pill has a mass of 0.65 g. How many pills does a pharmacist have if she has 324.56 g of pills? 2) A star has a mass of 2X1036 kg and a diameter of 7.0X105 km. What is the density of the star in g/cm3? Volume of a sphere = (4/3)pr3p = 3.14 3) The density of a diamond is 3.51 g/cm3. What would be the volume of 0.724 g of diamond? 4) In Raiders of the Lost Ark, Indiana Jones replaces a gold statue with a bag of sand. If gold has a density of 19.32 g/mL and sand has a density of 2.0 g/mL, is it possible that a bag of sand equal in volume to the gold statue would have the same mass as the statue? If the volume of the statue was 1.0 L what would the mass of the statue be in grams? In pounds? (2.2 lb = 1 kg)

23. Conversion Review/Practice: 1 Gm = 1X109 m 1 Mm = 1X106 m 1 km = 1X103 m 1 m = 1X102 cm 1 m = 1X103 mm 1 m = 1X106mm 1 m = 1X109 nm 1. Convert 3,400 nm to mm 2. Convert 0.0000572 cg to mg 3. Convert 5.80X1010 ms to ks 4. Convert 7.305X1010 seconds to years 5. Convert 4.98X10-2 yards to inches

24. Conversion Review/Practice: 1 Gm = 1X109 m 1 Mm = 1X106 m 1 km = 1X103 m 1 m = 1X102 cm 1 m = 1X103 mm 1 m = 1X106mm 1 m = 1X109 nm 6. Convert 8,300,000 mm3 to cm3 7. Convert 39 m/s to km/week 8. Convert 5.80X1010 ng/mL to cg/mL 9. Convert 7.305X10-10 g/day to ng/min 10. Convert 4.98X10-7 kL to in3