Chemistry: The Science of Matter CHAPTER

Transcription

1 Reviewing Vocabulary Choose from the terms below to complete each statement. alloy element mass quantitative aqueous solutions endothermic matter scientific model chemical change energy mixture solute chemical property exothermic physical change solution chemical reaction formula physical property solvent chemistry law of conservation properties substance compound of mass qualitative volatile density. The type of change in which the identity of substances does not change is known as a(n). 2. A(n) is a chemical combination of two or more elements joined together in a fixed proportion. 3. The fact that matter can be neither created nor destroyed in a chemical change is called the. 4. Solutions in which water is the solvent are. 5. The behavior of matter describes its characteristics, or. 6. A(n) is a solid solution usually consisting of two or more metals. 7. Any chemical reaction that gives off energy is said to be. 8. The combination of chemical symbols that describes the composition of a chemical compound is known as a(n). 9. is the measure of the amount of matter that an object contains. 0. A(n) observation is one that makes use of measurement.. A(n) can be observed only when there is a change in composition of a substance. 2. is anything that takes up space and has mass. 3. The material that is dissolved in a solution is the. 4. The capacity to do work is called. Chemistry: Concepts and Applications, Chapter 5

2 Understanding Concepts Part A In the space at the left, write the letter of the word or phrase that best completes the statement or answers the question.. A physical property of zinc metal is. a. its color c. how it reacts with nitrogen gas b. whether it burns d. whether it changes when placed into acid 2. The best way to understand the submicroscopic world is with. a. powerful microscopes c. physical properties b. very accurate measuring d. models devices 3. Which of the following materials cannot be broken down into a simpler form? a. compound c. mixture b. solution d. element 4. An example of a pure substance in everyday life is. a. pond water c. a cola drink b. sugar d. concrete 5. An example of a chemical change is. a. melting c. burning b. electrical conductivity d. density 6. An example of a chemical formula is. a. Na c. H 2 SO 4 b. 4.5 g/ml d. d 3.6 g/l 7. The density of a material depends on. a. its mass only c. its mass and volume b. its volume only d. its weight 8. In a list of the densities of common materials, the one density that might not seem reasonable is. a g/ml c g/ml b g/ml d..000 g/ml 6 Chemistry: Concepts and Applications, Chapter

3 Understanding Concepts Part B In the space provided, explain how the two terms in the following pairs relate to one another.. matter and mass 2. chemical property and physical property 3. heterogeneous and homogeneous 4. pure substance and element 5. qualitative observation and quantitative observation 6. mixture and solution 7. solution and alloy 8. solution and aqueous solution 9. sodium and Na 0. Na and NaCl. density and mass 2. freezing point and melting point 3. endothermic and exothermic Chemistry: Concepts and Applications, Chapter 7

4 Thinking Critically Listed below are a number of changes that can be observed in everyday life. Tell whether each change is a physical change or a chemical change. Then explain the basis on which you made your decision.. an icicle melting 2. charcoal burning 3. magnetizing a piece of steel 4. iron rusting 5. rubbing alcohol evaporating from the skin Answer each of the following questions. 6. Suppose you were given a mixture of sand and salt to separate from each other. What physical property could you use to accomplish this task? 7. A test tube without any label contains a clear liquid known to be either pure water or ethanol (ethyl alcohol). What physical properties could you use to tell what the liquid is? 8. A white solid is heated in a test tube. The solid slowly changes color to a grayish powder, and a gas escapes from the test tube. Is the white solid an element or a compound? Is the grayish powder an element or a compound? Explain your answers. 8 Chemistry: Concepts and Applications, Chapter

5 Interpreting Data and Lab Skills The table below gives the density of selected substances. Answer the following questions. Substance Density (g/ml) water (at 4.0 C).000 hydrogen carbon dioxide XXX gasoline 0.68 copper 8.89 silver 0.5 mercury tungsten 9.3. Which of the substances listed in the table has the greatest density? the lowest density? 2. If you were given a milliliter of copper and a milliliter of silver, which would weigh more? 3. Corks are used on fishing lines because they float. What can you say about the density of cork? 4. To complete the table, calculate the density for carbon dioxide if ml of the gas has a mass of g. 5. Suppose that 0 ml of each of the three liquids in the table water, gasoline, and mercury were all placed in a test tube. The liquids do not mix with one another. In the three layers that would be produced, which liquid would be on top, which in the middle, and which on the bottom? Chemistry: Concepts and Applications, Chapter 9

6 Performance Assessment To produce the page you are reading, chemists have studied how to make various kinds of papers and inks, how to coat the paper to give it longer life, and how to glue a cover on the book so that it will not fall apart. The purpose of this activity is for you to think about other ways in which chemistry affects your own life. Your assignment is to write a series of five questions about your daily life that you think chemistry might be able to answer for you. The key to any good research question is that it be as specific as possible, not How do you make ink? but How do you make a blueblack ink that can be used in printing on high-gloss paper and that will not fade when exposed to sunlight? To improve the quality of your questions, give them to another student in class to read and comment on. The purpose of this step is to find out if the questions you write are as clear to someone else as they are to you. Questions for Chemistry to Answer About My Life Chemistry: Concepts and Applications, Chapter