Unit 1 Worksheet Packet KEY

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1 Unit Worksheet Packet KEY Name Period Worksheet (Goals 6) SECTION 2. PROPERTIES of MATTER (pages 34 37) This section helps you identify the characteristics of matter and substances. It teaches you how to differentiate among the three states of matter. It also defines a physical property and lists examples of physical properties and physical changes. Describing Matter (pages 34 35). What is matter? Matter has mass and takes up space. 2. The mass of an object is the amount of matter the object contains. 3. What is an extensive property? An extensive property depends on the amount of matter in a substance. 4. What is an intensive property? An intensive property depends on the type of matter in a sample. 5. Matter that has a uniform and definite composition is called a substance. 6. How many kinds of matter does a pure substance contain? one 7. Is the following sentence true or false? All samples of a substance have different physical properties. false 8. A physical property is a quality or condition of a substance that can be observed or measured without changing the substance s composition. 9. Circle the letter of the term that is NOT a physical property. a. odor b. density c. boiling point d. corrosion 0. Is the following sentence true or false? A chemist can help identify a substance by its physical properties. true States of Matter (pages 36 37). Circle the letter of the term that is NOT a physical state of matter. a. water b. gas c. liquid d. solid

2 2. Match each arrangement of the particles in matter with a physical state. Physical State Arrangement c gas a. packed tightly together b liquid b. close, but not rigidly packed a solid c. spaced far apart 3. Is the following sentence true or false? The words gas and vapor can be used interchangeably. false 4. The term gas is limited to those substances that exist in the gaseous state at ordinary temperature and pressure. 5. What is vapor? Vapor is a gas in equilibrium with liquid at room temperature. Physical Changes (page 37) 6. A physical change alters a given material without changing its chemical composition. 7. What are some words that describe physical change? cut, grind, bend, melt, boil, dissolve 8. What do boiling, melting and freezing have in common? all are physical changes SECTION 2.2 MIXTURES (pages 38 4) This section explains how to categorize a sample of matter as a substance or a mixture. It also teaches you how to distinguish between homogeneous and heterogeneous samples of matter. Classifying Mixtures (pages 38 39) 9. Is the following sentence true or false? Most samples of matter are mixtures. true 20. What is a mixture? physical blend of two or more substances 2. Is the following sentence true or false? A heterogeneous mixture is one that has a completely uniform composition. false 22. What is another name for a homogeneous mixture? solution 23. Circle the letter of the term that describes a part of a system with uniform composition and properties. a. solution b. mixture c. state d. phase 24. How many phases exist in these types of mixtures? a. Homogeneous one b. Heterogeneous two or more

3 Match each type of solution with an example of it. 25. b solid-solid a. sugar water 26. a solid-liquid b. carbon mixed with iron to form steel 27. c gas-liquid c. soda water 28. d gas-gas d. air Separating Mixtures (pages 40 4) 29. Is the following sentence true or false? It is always easy to separate the components in mixtures. false SECTION 2.3 ELEMENTS AND COMPOUNDS (pages 42 47) This section explains the difference between an element and a compound. It also helps you identify the chemical symbols of common elements, and name common elements, given their symbols. Distinguishing Elements and Compounds (pages 42 43) 30. What are the two groups into which substances can be classified? elements and compounds 3. Is the following sentence true or false? Elements can be separated easily into simpler substances. false 32. Compounds are substances that can be separated into simpler substances only by chemical means. 33. Is the following sentence true or false? The properties of compounds are different from those of their component elements. true Distinguishing Substances and Mixtures (page 44) 34. Is the following sentence true or false? The elements that make-up a substance is always present in the same proportions. true Symbols and Formulas (pages 45 47) 35. What is used to represent each element? chemical symbol 36. What are chemical symbols used for? represent elements 37. The subscript numbers in chemical formulas represent the proportions of the various elements in the chemical formula. 38. Use the periodic table to answer the following questions. a. Pb is the symbol for what element? lead b. What is the symbol for gold? Au c. Stibium is the Latin name for which element? antimony

4 SECTION 2.4 CHEMICAL REACTIONS (pages 48 50) This section helps you differentiate between physical and chemical changes in matter. It also teaches you how to apply the law of conservation of mass. Chemical Changes (page 48) 39. What happens in a chemical reaction? Reactants are converted to products. 40. What is a chemical property? A property observed by changing a substance s chemical composition. 4. Is the following sentence true or false? Chemical properties are observed only when a substance undergoes a chemical change. true 42. In chemical reactions, the starting substances are called reactants and the substances formed are called products. 43. Circle the letter of the term that best completes the sentence. A chemical change results in a change in chemical composition of the substances involved. a. sometimes b. rarely c. always d. never Recognizing Chemical Reactions (page 49) 44. What are some words that describe chemical change? formation of gas/solid/liquid, energy, irreversibility 45. Which representation of a chemical reaction is correct? a. Products Reactants b. Reactants Products Conservation of Mass (page 50) 46. During a chemical reaction, the mass of products is always equal to the mass of the reactants. 47. The law of conservation of mass states that in any physical change or chemical reaction, mass is neither created nor destroyed.

5 Chemical vs. Physical Properties, Elements, Compounds and Mixtures Name Period Worksheet 2 (Goals 6). In your own words, differentiate between the following terms: Chemical Change and a Physical Change A chemical change is a change resulting in a new substance with a different chemical composition. A physical change is a change resulting in the same substance without a change in chemical composition. Chemical Property and Physical Property A chemical property is the ability of a substance to undergo a specific chemical change. A physical property is a quality or condition of a substance that can be observed or measured without changing the substance s chemical composition. 2. Indicate whether the following are physical or chemical changes. a. Melting candle wax Physical b. Tearing Mg ribbon Physical c. Adding HCl to Mg Chemical d. Tearing Paper Physical e. Grinding CuSO 4 Physical f. Burning Paper Chemical g. Heating CuSO 4 Chemical or Physical h. Dissolving NaCl Physical i. Mixing NaCl and Sand Physical

6 3. Describe the difference between elements, compounds, and mixtures. Give an example of an element, which is then in a compound, which is also in a mixture. Elements are the simplest form of matter with a unique set of properties and cannot be broken down into simpler substances by chemical means. Compounds are substances containing two or more elements chemically combined in fixed proportions. Mixtures are physical blends of two or more substances that are not chemically combined. Example: Oxygen is an element in the compound H2O in the mixture salt water. 4. Can a compound be broken down to smaller components (i.e. elements or smaller compounds) by physical means? Use an example to support your position. A compound cannot be broken down into smaller components by physical means because substances are chemically combined. Compounds can only be broken down into simpler substances by chemical means. Example: Water, H2O, can t be separated into hydrogen and oxygen by boiling it. 5. Describe the difference between a homogenous mixture and a heterogeneous mixture. Provide an example of each and explain why they homogeneous or heterogeneous. A homogeneous mixture is uniform throughout and visibly indistinguishable. Salt water is an example of a homogeneous mixture. The salt solution is uniform throughout with no distinguishable parts. A heterogeneous mixture is not uniform throughout and has visibly distinguishable parts. A salad is a heterogeneous mixture. There are many different regions of differing composition in a salad. 6. Discuss why physical properties are better to use to separate mixtures than chemical properties. Use an example to illustrate your point. Since mixtures are physical blends of two or more substances, they are can be separated by utilizing the differences in the unique physical properties of each component of the mixture. It is easier to separate salt water by simply boiling away the water than to produce a reaction to react with each component of a mixture and then separate the new compounds (and reverse the reaction to get the original compounds).

7 Qualitative vs. Quantitative, Accuracy vs. Precision Name Period Worksheet 3 (Goal 8). Identify the following as quantitative or qualitative measurements. a. A flame is hot. Qualitative b. A candle has a mass of 90 g. Quantitative c. Wax is soft. Qualitative d. A candle s height decreased 4.2 cm/hr. Quantitative 2. Which of these synonyms or characteristics apply to the concept of accuracy? Which apply to the concept of precision? a. multiple measurements Precision b. correct Accuracy c. repeatable Precision d. reproducible Precision e. single measurement Accuracy f. true value Accuracy 3. Under which circumstances could a series of measurements of the same quantity be precise but not accurate? A series of measurements is precise as long as they are reproducible. To be accurate, a measurement must be compared to an accepted or true value. If a series of measurements are reproducible, but no true value is known they cannot necessarily be described as accurate. 4. Comment on the accuracy and precision of these basketball free-throw shooters. a. 99 of 00 shots are made. Precise and Accurate b. 99 of 00 shots hit the front of the rim and bounce off. Precise c. 33 of 00 shots are made; rest miss. Neither Precise nor Accurate 5. A student estimated the volume of a liquid in a beaker as 200 ml. When she poured the liquid into a graduated cylinder, she measured the volume as 208 ml. What is the percent error of the estimated volume from the beaker, taking the measurement in the graduated cylinder as the accepted value? % = = 3.8%

8 Significant Figures Name Period Worksheet 4 (Goals 0 and ). How many significant figures are there in each of the following quantities? a. 20 miles b g 2 c. m 2 d s 2 e o C 3 f. 404 people g. 8.9 x 0-2 kg 2 h L 3 i. 22,000 s 2 2. Round each of these measurements to three significant figures. a L 98.5 L b cg cg c m 57.0 m d. 2.7 o C 2.2 o C e x 0 4 mm 75.0 mm f ml 760 ml 3. Write each of the rounded measurements in problem 2 in scientific notation. a x 0 L b x 0-3 cg c x 0 m d..22 x 0 o C e x 0 mm f..76 x 0 3 ml 4. Round off the following numbers to the number of significant figures indicated. a..034 g (2 sig fig).0 g b s (3 sig fig) 40. s c L (2 sig fig) 6.2 x 0-5 L d..549 mm ( sig fig) 2 mm e ml (3 sig fig) 7.40 x 0 2 ml f kg ( sig fig) 80 kg 5. Express the following calculations in the proper number of significant figures and units. a. 29 g / 29.2 cm g/cm 3 b m / 45.4 s m/s 2 c..55 m x m m 2 d. 60 cm x cm 7 x 0 5 cm 2 e mm x mm x mm 3.5 mm 3 6. Express the following calculations in the proper number of significant figures. a. 22 g g g 33 g b cm + 9. cm 53.8 cm c ml ml 6.4 ml d g 4 g 2 g e. 7.6 K K K 0.7 K

9 7. Water with a mass of 35.4 g is added to an empty flask with a mass of g. The mass of the flask and the water is g after a rubber stopper is added. Express the mass of the stopper to the correct number of significant figures. mass of stopper = total mass (mass of water + mass of flask) mass of stopper = g ( g g) = 23.9 g 8. A student measures the mass of an object to be 95.3 grams using an electronic balance. When placed in a graduated cylinder, the object displaced 9.9 ml of water. What is the density of the object? D = m/v = 95.3 g/9.9 ml = 2.0 x 0 g/ml 9. What is the volume of a glass cylinder with an inside diameter of 6.0 cm and a height of 28 cm? (The volume of a cylinder equals pi x radius squared x height) V = (D/2) 2 H = (6.0 cm/2) 2 28 cm = 790 cm 3

10 Metric Unit Conversions and Dimensional Analysis Name Period Worksheet 5 (Goals 2 4) km = 000 m kg = 000 g L = 000 ml Kelvin = o C m = 0 dm g = 0 dg ml = cm 3 00 cm 00 cg 000 mm 000 mg x 0 6 µm x 0 6 µg x 0 9 nm x 0 9 ng Convert the Following Units: Show All of Your Work (Use Dimensional Analysis) 63 m km = m mm = kg g = 98, cm m = ml L = o C K Kelvin = = 309 K 6.3 x 0 3 mg g = L ml = K o C = = 50

11 . List the SI base unit for each of these quantities. a. time second (s) b. length meter (m) c. temperature Kelvin (K) d. mass kilogram (kg) 2. Which would melt first, germanium (m.p.,20 K) or gold (m.p.,064 o C)? o C =,20 K 273 = 937 o C Germanium would melt first because it has a lower melting point. 3. A quarter has a mass of about 5.65 g. Express this mass in milligrams, kilograms and micrograms = = = Write the following numbers in scientific notation. a x0 - b. 25, x0 4 c x0-4 d.,000,000 x0 6 e x Which is larger? a. centigram or milligram b. liter or centiliter c. calorie or kilocalorie d. millisecond or centisecond e. microliter or milliliter f. cubic millimeter or cubic decimeter 6. Make the following conversions. a ml/min to microliters per second μ = 7.3 μ / b g/cm 2 to milligrams per square millimeter = 78.6 / c..54 kg/l to grams per cubic centimeter =.54 / 7. A tank measuring 28.6 cm by 73.0 mm by 0.72 m is filled with olive oil that has a mass of.38 x 0 4 g. What is the density of olive oil in kilograms per liter? = = ; 73.0 = 7.30 ; 0.72 = 72 0 = = = = = 0.92 /