Measurement CHEM 10 Review Worksheet Units, Conversions, Density and Temperature

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1 Measurement CHEM 10 Review Worksheet Units, Conversions, Density and Temperature The problems on this worksheet are Chem 10 level problems. They are provided to assist your review of some topics covered in Chp 1 of the Zumdahl textbook. Note that Chem 11 problems will be more involved and more rigorous than these! An answer key is provided at the end of this worksheet. Part 1: Numbers and Units in Measurements 1. Record the measurements shown on the following instruments with the correct number of significant figures. C cm ml 2. How many significant figures are in the following measurements? Measurement # Significant Figures Measurement # Significant Figures ounces x 10 3 meters seconds gallons 3. Which of the following quantities are exact numbers? 0.50 lbs 17 eggs 300 K ¾ mile How many significant figures are in an exact number? 4. Write the numbers in the table below in scientific notation. Number x x 10 7 Number in Scientific Notation 5. Write the following numbers in standard notation (also called decimal notation). Number 5.19 x x 10-2 Number in Standard Notation 6. Perform the following calculations without using a calculator for the exponents. Report your final answer in scientific notation and to the correct number of significant figures. 7 ( ) 8 ( ) = ( ) 4 = 4 ( ) ( ( ) 3 ) = 7 9 ( ) ( ) =

2 7. Round off the following numbers: to 4 sig figs to 2 sig figs to 3 sig figs to 2 sig figs 8. Perform the calculations below and report your answers to the correct number of significant figures. a. (3.1 x ) 2.34 = b. ( ) / 4.7 = c. To a beaker weighing g, you add g of water and g of sugar. Determine the combined mass of the beaker, water and sugar (in g). d. The sides of a block of solid copper metal are measured to be 6.58 cm, cm and 0.82 cm (length, width and height). Determine the volume of this block (in cm 3 ). 9. S.I. units are standard units of measurement agreed upon by the scientific community. a. What are the S.I. units that are used to measure the properties of matter below? Temperature: Length: Mass: Time: b. Acceleration (a) has the formula: a = velocity/time. What is the derived S.I. unit for acceleration? c. Force has the formula: force = mass x acceleration. What is the derived S.I. unit for force? (note this unit is also known as the Newton) 10. Prefixes can either increase or decrease the size of a unit. Circle the larger unit in each of the pairs below. kilometer (km) or centimeter (cm) nanosecond (ns) or picosecond (ps) 11. Write the conversion relationships for each of the sets of units given below. Use the format: 1 Big Unit = Many Little Units. milligram (mg) or hectogram (hg) microliter (µl) or deciliter (dl) m and hm GW and TW (W is Watts) dg and Mg L and pl ns and fs µj and kj 12. Consider the conversion relationship 1 kg = 10 3 g. Now write it in reverse: 1 g =??? kg

3 Part 2: Dimensional Analysis and Unit Conversions 1. A radioactive atom decays in 52.8 ps. Convert this to seconds. 2. A computer contains Mbytes of RAM. Convert this to bytes. 3. The volume of a certain raindrop is 0.16 cl. Convert this to microliters. 4. The length of a piece of tin is measured to be 63.7 mm. Convert this to hectometers. 5. A student weighs 155 lbs. Convert this to kilograms (1 lb = g). 6. A soda bottle contains 750 ml of soda. How many quarts of soda do you have? 7. A mountain has an altitude of 6684 ft (above sea-level). Convert this to meters. 8. A jogger runs at an average speed of 6.50 miles/hr. Convert this to meters/second (1 km = mi). 9. A sheet of notebook paper has an area of cm 2. What is the area of this paper in nm 2 and ft 2? 10. A 2.00 ml sample of pond water is analyzed and determined to contain 0.71 µg of lead. If the pond contains 6.8 x 10 5 gallons of water, what is the mass (in g) of lead in the entire pond? 11. Jamaican sprinter Usain Bolt ran the 200 m event in a record time of s. Assuming he was able to maintain the same average speed indefinitely, how many minutes would it take Mr. Bolt to run 3.00 miles? 12. A perfect sphere has a measured radius of 4.64 cm. Calculate the volume of this sphere in cm 3 and in dl.

4 Part 3: Density Calculations 1. The density of lead is g/cm 3. Convert this to lbs/inch 3 (given that 1 lb = g, 1 inch = 2.54 cm) 2. A perfect cube of a solid metal weighs kg and has an edge length of 30.0 mm. Calculate the density of this metal, in g/cm 3, then use Table 2.4 in your textbook to identify this metal. 3. A solid object has a mass of 422 dg. When the object is placed in a graduated cylinder containing ml of water, the level rises to ml. What is the density of this object in g/ml and g/cm 3? 4. Mercury is the only metal that is a liquid at room temperature. Mercury has a density of 13.6 g/ml. What volume, in ml, would a 725 kg sample of mercury occupy? 5. A cylindrical piece of Teflon has a measured diameter of 2.74 cm and a height of cm. Given that Teflon has a density of 2.2 g/cm 3, what is the mass of this cylinder (in grams)? 6. A recycling center collects 1254 aluminum cans. If 44 cans weigh 2.00 pounds, what volume, in cm 3, of aluminum was collected? The density of aluminum is g/cm A full tank of gasoline in a certain car has a volume of 12.0 gallons. The density of gasoline is g/ml. What is the mass (in kg) of 12.0 gallons of gasoline (given that 1 L = gallons)? 8. A can contains 9.9 lbs of paint. What is the maximum surface area, in ft 2, that can be painted using all the paint in the can? Assume that a single layer of paint on a surface has a thickness of 115 µm, and the density of the paint is 1.20 g/ml. [Hint: Volume = Area x thickness]

5 Part 4: Temperature Scales and Conversions 1. Which temperature scale: -- is designed based on the freezing and boiling point of water? -- is referred to as the absolute temperature scale? 2. A person with a fever has a temperature of ºF. Convert this to ºC. 3. Ethanol boils at a temperature of 78.6 ºC. Convert this to ºF and K 4. A recipe requires an oven temperature of 450 ºF. Convert this to K. Answer Key Part cm 30.0 ml 28.5 C ounces (5 sfs) (3 sfs) x 10 3 meters (6 sfs) gallons (7 sfs) eggs (counted value), 3/4 mile (simple fraction of a defined quantity). Exact numbers have no uncertainty, thus they have infinite significant figures x x x x x x x x (a) 5.2 (b) 21 (c) grams (d) 81 cm 3 9. (a) Temperature: Kelvins Mass: kilograms Length: meters Time: seconds (b) m/s 2 (c) kg m/s kilometer hectogram nanosecond deciliter hm = 10 2 m 1 L = pl 1 TW = 10 3 GW 1 ns = 10 6 fs 1 Mg = 10 7 dg 1 kj = 10 9 µj g = 10-3 kg Part x s x 10 8 bytes x 10 3 µl x 10-4 hm kg qts m m/s x nm ft g lead minutes cm dl

6 Part lbs/inch g/cm 3 Copper g/ml 9.17 g/cm x 10 4 ml g x 10 3 cm kg ft 2 Part 4 1. The Celsius scale has a design based on the freezing and boiling points of water. The Kelvin scale is known as the absolute temperature scale C F and Κ K (note that the original temperature of 450 F only has 2 sfs, no dps and no places in the 1s)