1. Elemental mercury is a shiny, silver-colored, dense liquid that flows easily. Are these characteristics of mercury physical or chemical properties?

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1 Chemistry Dr. Saulmon School Year Unit 2: Basics of Chemistry Problem Set 3 Wednesday, September 3, Elemental mercury is a shiny, silver-colored, dense liquid that flows easily. Are these characteristics of mercury physical or chemical properties? 2. Magnesium metal is very malleable, and is able to be pounded and stretched into long, thin, narrow ribbons that are often used in the introductory chemistry lab as a source of the metal. If a strip of magnesium ribbon is ignited in a Bunsen burner flame, the magnesium burns brightly and produces a quantity of white magnesium oxide powder. (a) From the information given, indicate one chemical property of magnesium metal. (b) From the information given, indicate one physical property of magnesium metal. 3. Discuss the similarities and differences between a liquid and a gas. 4. Which of the following is not a physical property of aluminum? a. It is a shiny metal b. It can be hammered into thin sheets c. It melts at 660 C d. It burns in air if heated strongly 5. Choose a chemical substance with which you are familiar, and give an example of a chemical change that might take place to the substance. 6. Classify each of the following as a physical or chemical change. a. Mothballs gradually vaporize in a closet. b. A French chef making a sauce with brandy is able to burn off the alcohol from the brandy, leaving just the brandy flavoring. c. Hydrofluoric acid attacks glass, and is used to etch calibration marks on glass laboratory utensils.

2 d. Calcium chloride lowers the temperature at which water freezes, and can be used to melt ice on city sidewalks and roadways. e. An antacid tablet fizzes and releases carbon dioxide gas when it comes in contact with hydrochloric acid in the stomach. f. Baking soda fizzes if mixed with vinegar. g. Chemistry majors usually get holes in the cotton jeans they wear to lab because of the acids used in many experiments. h. Whole milk curdles if vinegar is added to it. i. A piece of rubber stretches when you pull on it. j. Rubbing alcohol evaporates quickly from the skin k. Acetone is used to dissolve and remove nail polish. l. Butter turns rancid if left exposed at room temperature. m. Salad dressing separates into layers after standing. n. The steel in a car has rust spots. o. A person is asphyxiated by breathing carbon monoxide. p. Sulfuric acid spilled on a laboratory notebook page causes the paper to char and disintegrate. q. Sweat cools the body as it evaporates from the skin. r. Aspirin reduces fever. s. Oil feels slippery. t. Alcohol burns, forming carbon dioxide and water. 7. Certain elements have special affinities for other elements. This causes them to bind together in special ways to form.

3 8. If a piece of hard white blackboard chalk is heated strongly in a flame, the mass of the piece of chalk will decrease, and eventually the chalk will crumble into a fine white dust. Does this change suggest that the chalk is composed of an element or a compound? 9. Suppose a teaspoon of magnesium filings and a teaspoon of powdered sulfur are placed together in a metal beaker. Would this constitute a mixture or a pure substance? 10. What does it mean to say that a solution is a homogeneous mixture? 11. Classify the following as mixtures or as pure substances. a. The air you are breathing. b. The soda you are drinking while reading this book. c. The water with which you just watered your lawn. d. The diamond in the ring that your fiancé just presented to you. e. The sugar you just put into your coffee while studying. f. The perfume you dab on before you go on a date. g. The black pepper you grind onto your salad at dinner. h. The distilled water you use in your iron so it won t get clogged. 12. Classify the following mixtures as heterogeneous or homogeneous. a. Soil b. Mayonnaise c. Italian salad dressing d. The wood from which the desk you are studying on is made

4 e. Sand at the beach f. Baby oil g. The potting soil you planted your African violet in h. A supreme pizza i. Freshly squeezed orange juice j. White glue. 13. Give an example of each of the following: a. A heterogeneous mixture b. A homogeneous mixture c. An element d. A compound e. A physical property or change f. A chemical property or change g. A solution 14. In a common laboratory experiment in general chemistry, students are asked to determine the relative amounts of benzoic acid and charcoal in a solid mixture. Benzoic acid is relatively soluble in hot water, but charcoal is not. Devise a method for separating the two components of this mixture.

5 15. The letters C, S, and T have been very popular when naming the elements, and there are ten or more elements whose names begin with each of these letters. For each letter, find and list all the elements whose names (not symbols) start with that letter. 16. Use the periodic table to look up the symbol or name for each of the following elements. Symbol Pd Ir Lr Cs Tl Name Tungsten Germanium Platinum Zirconium Praseodymium Osmium Titanium 17. Imagine you are talking about chemistry to your friend who has not taken any science courses. Explain to him in your own words the five main points of Dalton s atomic theory.