Practice with Properties of Matter. Practice with Physical and Chemical Changes. Practice with Mixtures and Pure Substances

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1 Chapter 1 Practice Problems Practice with Properties of Matter Indicate whether each of the following statements describes a physical or a chemical property. a) the normal color of elemental bromine is orange. b) iron turns to rust in the presence of air and water. c) hydrogen can explode when ignited in air. d) the density of titanium metal is 4.5 g/cm 3. Practice with Physical and Chemical Changes Classify each of the following as a physical or chemical change in properties. a) a cup of household bleach changes the color of your T-shirt from purple to pink. b.) c.) d.) water vapor in your inhaled breath condenses in the air on a cold day. plants use carbon dioxide from the air to make sugar. butter melts when placed in the sun. Practice with Mixtures and Pure Substances Classify each of the following as a mixture or pure substance and if it s a pure substance, state whether it is an element or a compound. a.) water b.) iron c.) blood d.) brass e.) the Pacific Ocean f.) ammonia Complete the following table. Practice with Scientific Notation Standard Notation Size (small or large) Scientific Notation x x x

2 Practice with Significant Figures and Rounding Off 1.) How many significant figures does each of the following measurements have? a.) L b.) 437,000 miles c.) kg d.) 106 J e.) 320 seconds (calculated from experiment) 2.) Express the following measurements to 2 significant figures using scientific notation. a.) 200,021 m b.) 555 miles c.) g d.) 4.37 dl Practice Calculating with Scientific Notation Express the result of the following calculations to the proper number of significant figures. a.) (2.1 x 10-5 ) x (0.753 x 10 2 ) = b.) (8.56 x 10-3 ) + (2.61 x 10-5 ) = c.) (4.35 x 10 6 ) / (8.2x10-3 ) = d.) (3.4 x x 10 4 ) / 2.5 x 10 3 = e.) 1.23 cm + 56 cm cm = f.) (200.1 in)(22.1 in)(0.56 in) = g.) ( ) = h.) (21.2)(2.54) = (2.231)(56.21) ( )( ) i.) (6.25 x 10 2 ) 3 = j.) (2.35 x 10-3 ) 1/3 = k.) (5.46 x 10-2 )(16.0 x 10 4 ) (7.779/55.85) = l.) [ (1.7 x 10 6 ) / (2.63 x 10 5 ) ] = 2

3 Practice with Unit Conversion Factors and Prefix Multipliers 1.) Match the prefix, symbol, and multiplier without using the book. Prefix Symbol Multiplier milli p nano d kilo ) Metric conversions. a.) 325 cm =? m b.) 2.5 um =? mm c.) cm =? mm d.) 8.25 x 10 8 ng =? mg e.) A US dime has a mass of g. What is this mass in kilograms? In milligrams? 3.) Conversions between systems. a.) 36.5 m =? ft b.) 2.56 qt =? L c.) 1.2 cup =? dl d.) 4.2 km =? yd 4.) Conversions between temperature scales. a.) 26.2 K =? C b.) 37.1 C =? K c.) F =? C d.) 350 C =? F e.) Neon, a gaseous element used in neon signs, has a melting point of C, and a boiling point of C. Express these temperatures in Kelvin. 3

4 Practice with Measurement Uncertainty Record the volume of the liquid in the graduated cylinder and buret below to the proper number of significant figures. The markings on the graduated cylinder are in ml

5 Practice with Density Calculations 1.) Etylene glycol, C2H6O2, is an ingredient of automobile antifreeze. Its density is 1.11 g/cm3 at 20 C. If you need exactly 500. ml of this liquid, what mass of the compound, in grams, is required? 2.) The cup is a volume measure widely used by cooks in the United States. One cup is equivalent to 237 ml. If 1 cup of olive oil has a mass of 205 g, what is the density of the oil (in grams per cubic centimeter)? 3.) The anesthetic procaine hydrochloride is often used to deaden the pain during dental surgery. The compound is packaged as a 10. % solution by mass in water (d = 1.0 g/ml for the solution). If your dentist injects 0.50 ml of the solution, what mass of procaine hydrochloride (in milligrams) is injected? 4.) Suppose you have a ml graduated cylinder containing 50.0 ml of water. If you drop a 154 g piece of brass (d = 8.56 g/cm 3 ) into the water, how high does the water rise in the graduated cylinder? 5

6 Practice with Measurement Reliability, Precision, and Accuracy The accepted value of the melting point of pure aspirin is 135 C. Trying to verify that value, you obtain the melting points of 134, 136, 133, and 138 C in four separate trials. Your partner finds melting points of 138, 137, 138, and 138 C. a.) Calculate the average value and percent error obtained by you and your partner. b.) Which of you is more accurate? Which of you is more precise? Practice with Dimensional Analysis 1.) A standard US postage stamp is 2.5 cm long and 2.1 cm wide. What is the area of the stamp in square centimeters? In square meters? 2.) A compact disk has a diameter of 11.8 cm. What is the surface area of the disk in square centimeters? In square meters? [area of a circle = π (radius) 2 ] 3.) The aluminum in a package containing 75 ft 2 of kitchen foil weighs approximately 12 ounces. Aluminum has a density of 2.70 g/cm 3. What is the approximate thickness of the aluminum foil in millimeters? (1 oz = 28.4 g) 6