<p>CHAPTER 1- Chemistry: The Study of Change DR. PAHLAVAN</p><p>1. Classify the following as a pure substance (element-compound) or a mixture (homogeneous-heterogeneous). a) air b) a nickel c) magnesium d) lotion d) salad dressing 2. Perform the following conversions: a) 0.0025 mm to nm b) 0.88 pm to cm c) 2.50x10-6 kg/L to mg/ ml 3. A cubic piece of a nickel metal measures 5.25 cm on each edge. If the density is 8.9 g/cm3, what is the mass of the cube? 4. Determine the number of significant figures in each of the following measured quantities? a) 0.000289 m b) 3.50x108 g c) 202.040 cm d) 8.089 L 5. Perform the following calculations and round off the answer to the proper significant figures: a) 1.25 m + 6.2 m – 8.01 m + 0.899 m = ______</p><p> b) 78.8680 g/ (23.5ml + 10 ml) = ______6. An automobile is able to travel 900 mi on 35.8 gal of gasoline, what is the gas mileage in km/L?</p><p>7. Neon has a low boiling point of approximately –246 oC. What is the boiling point in Kelvins and oF?</p><p>8. Round off the following to three significant figures: a) 134.89 m b) 80 g c) 1255 ml d) 1.2x10-5 mm</p><p>9. A balance has a precision of +/- 0.001g. A sample weighs about 8 g on this balance. How many significant figures should be reported for this measurement?</p><p>10. The density of a metal is 9.80 g/ml. What is the mass of a sample of metal when dropped in28.9 ml water, the volume increases to 56.4 ml?</p><p>11. Label each of the following as either a physical process (change) or a chemical process (change). a) The metal gets warmer b) Explosion of nitroglycerin c) Corrosion of Iron metal d) Water condenses on the metal</p><p>12. Identify the following characteristics as physical properties or chemical properties.</p><p> a) Silver metal is white b) Zinc has a density of 7.13 g/ml at 25 0C c) Silver is a lustrous metal d) Sodium is highly reactive with water CHAPTER 1- Chemistry: The Study of Change (answers) DR. PAHLAVAN</p><p>1. Classify the following as a pure substance(ps) (element-compound) or a mixture(m) (homogeneous-heterogeneous).</p><p> a) air (m –homogeneous , solution) b) a nickel (m) c) magnesium (ps)</p><p> d) lotion (m –homogeneous) d) salad dressing (m –heterogeneous)</p><p>2. Perform the following conversions: a) 0.0025 mm to nm  (0.0025mm)(1m/1000mm)(109 nm/1m) = 2500nm b) 0.88 pm to cm  (0.88pm)(1m/ 1012 pm)(100cm/1m) = 8.8 x10 -11 cm c) 2.50x10-6 kg/L to mg/ ml </p><p> (2.50 x10-6kg/L)(1000g/1kg)(1000mg/1g)(1L/1000ml) = 2.5 x 10 -3 mg/ml</p><p>3. A cubic piece of a nickel metal measures 5.25 cm on each edge. If the density is 8.9 g/cm3, what is the mass of the cube? </p><p>Mass = D.V. = (5.25cm)3 x 8.9 g/cm3 = 1287.9 g</p><p>4. Determine the number of significant figures in each of the following measured quantities?</p><p> a) 0.000289 m (3) b) 3.50x108 g (3) c) 202.040 cm (6) d) 8.089 L (4)</p><p>5. Perform the following calculations and round off the answer to the proper significant figures:</p><p> a) 1.25 m + 6.2 m – 8.01 m + 0.899 m = 0.3m</p><p> b) 78.8680 g/ (23.5ml + 10 ml) = 2.35g/ml</p><p>6. An automobile is able to travel 900 mi on 35.8 gal of gasoline, what is the gas mileage in km/L? </p><p> (900 mi/35.8 gal)(1.61 km/1 mi)(1 gal/ 4qts)(1.06qts/1 L) = 10.7 km/ L 7. Neon has a low boiling point of approximately –246 oC. What is the boiling point in Kelvins and oF? K = oC + 273 = -246 + 273 = 27 K</p><p> oF = (9/5)(-246) + 32 = -410.8 oF</p><p>8. Round off the following to three significant figures: a) 134.89 m = 135 m b) 80 g = 80.0 g c) 1255 ml = 1.26 x 103 ml</p><p> d) 1.2x10-5 mm = 1.20 x10-5 mm</p><p>9. A balance has a precision of +/- 0.001g. A sample weighs about 8 g on this balance. How many significant figures should be reported for this measurement? </p><p> 8.000 g  4 sig. fig.</p><p>10. The density of a metal is 9.80 g/ml. What is the mass of a sample of metal when dropped in28.9 ml water, the volume increases to 56.4 ml?</p><p>Mass = D.V = (9.80g/ml)(56.4ml – 28.9ml) = 2.70 x 10 2 g</p><p>11. Label each of the following as either a physical process (change) or a chemical process (change).</p><p> a) The metal gets warmer (physical) b) Explosion of nitroglycerin (chemical) c) Corrosion of Iron metal (chemical) d) Water condenses on the metal (physical)</p><p>12. Identify the following characteristics as physical properties or chemical properties.</p><p> a) Silver metal is white (physical) b) Zinc has a density of 7.13g/ml at 25 0C (physical) c) Silver is a lustrous metal (physical) d) Sodium is highly reactive with water (chemical) </p>