Unit 1, Lab 1. Your hypothesis:

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1 Title Unit 1, Lab 1 Purpose Questions, Hypotheses, Procedures Part I. Mass of Steel Wool Does the volume, or the size of something, affect mass? Your hypothesis: 1. Obtain a plastic weighing tray, place it on the balance, and zero the balance. 2. Place a wad of steel wool in the weighing tray and record the mass. g 3. Over the weighing tray, carefully pull the wad of steel wool out to double its original size. 4. Record the mass of the wad of steel wool again. g 5. Report any change in mass by doing the following calculation: Mass steel wool after _ Mass steel wool before Change in mass Part II. Mass of Ice and Water When water melts, it takes up less volume than the ice did. What happens to the mass? Your hypothesis: 1. Obtain a beaker with a couple chips of ice. 2. Record the mass of the beaker with the ice. g 3. Allow the ice to melt completely. You should move on to part III while you wait. 4. Record the mass of the beaker and the liquid water. g 5. Calculate any change in mass by doing the following calculation. Mass of beaker + ice _ Mass of beaker + liquid water Change in mass 6. Pour out the water. Part III. Mass of a Precipitate When some solutions are combined, a solid forms (called a precipitate). Does the mass change when the solid is formed? Your hypothesis: 1. Obtain one small vial of 0.1 M calcium nitrate solution, Ca(NO3)2 (aq), and one small vial of 0.1 M sodium carbonate solution, Na2CO3 (aq). 2. Find the mass of the two capped vials together. g 3. Carefully pour the contents of one of the vials into the other vial and cap the vial. 4. Find the mass of both vials and caps together. g 5. Calculate any change in mass. 6. Clean out the vials. 1

2 Part IV. Mass of Burning Steel Wool What will happen to the mass of steel wool when it is burned? Your hypothesis: 1. Take out the stretched out piece of steel wool from part I and place it into the porcelain evaporating dish. 2. Using a balance, record the mass of the dish and the wad of steel wool. g 3. Place the evaporating dish with the steel wool on the lab table. 4. One person needs to hold the steel wool using tongs over the evaporating dish. Another person should heat the steel wool with a match over the evaporating dish until it glows. Turn the steel wool around in the flame so that all sides are exposed. 5. Repeat step # 3 two more times. You may not use more than 3 matches. 6. Describe how the appearance of the steel wool changes when it is heated strongly. 7. Find the mass of the evaporating dish and the steel wool again. g. 8. Calculate any change in mass. 9. Discard steel wool in trash and wipe out evaporating dish. Part V. Mass of Dissolved Sugar A soluble solid (i.e. sugar) appears to disappear in solution (i.e. mixed with water). What happens to the mass of the system when sugar is dissolved in water? (sugar + water before dissolving compared to sugar + water after dissolving)? Your hypothesis: 1. Fill a vial about ½ full of water. Then put about a ¼ tsp of sugar in the cap of the vial. 2. Record the mass of the vial of water and the cap of sugar. g 3. Carefully pour the sugar into the vial of water (try not to spill any). Cap the vial and gently swirl the vial until the sugar is dissolved. 4. Record the mass of the capped vial of sugar water. g 5. Calculate any change in mass. 6. Clean out the vial. Part VI. Mass of Dissolved Alka-Selzter What happens to the mass of the system when an alka-selzter tablet is dissolved in water (a-s + water before dissolving compared to a.s + water after dissolving)? Your hypothesis: 1. Fill a vial about ½ full of water. Then put about a ¼ tablet of alka-seltzer in the cap of the vial. 2. Find the mass of the vial of water and the cap of AS. g 3. Carefully place the AS into the vial of water (try not to spill anything). Do not cap the vial. Gently swirl the vial until the alka seltzer is dissolved. After the AS is dissolved completely, cap the vial. 4. Find the mass of the capped vial of AS water. g 5. Calculate any change of mass. 6. Clean out the vial. 2

3 Final Procedures and Clean Up 1. All trash should be disposed of appropriately. All vials, beakers, evaporating dishes should be rinsed, cleaned, and dried. Your lab table should be clean and neat for the next class. All necessary materials should be present in the container on your lab table (if a material needs to be replenished, let the instructor know before you leave). 2. Report your results on the smart board so that the entire class data can be recorded. Change should be recorded as + (for a gain) or (for a loss). 3. Make a data table for your data for all six parts of the lab. Remember: When making data tables, the independent variable should be the first column and the dependent variable should be in the next few columns. A calculated column is often the last column. Column headers should include units. All tables need to be numbered with an appropriate title that appears above the table. 3

4 Post-Lab Questions and Notes Part I Mass of Steel Wool. Draw particle diagrams representing the ideal data. Before After What should have happened to the mass of the system? Justify your answer. Provide an explanation of possible lab errors. Final mass was too high: Final mass was too low: Part II Mass of Ice and Water. Draw particle diagrams representing the ideal data. Before After What should have happened to the mass of the system? Justify your answer. Provide an explanation of possible lab errors. Final mass was too high: Final mass was too low: 4

5 Part III Mass of a Precipitate. Draw particle diagrams representing the ideal data. Before After What should have happened to the mass of the system? Justify your answer. Provide an explanation of possible lab errors. Final mass was too high: Final mass was too low: Part IV Mass of Burning Steel Wool. Draw particle diagrams representing the ideal data. Before After What should have happened to the mass of the system? Justify your answer. Provide an explanation of possible lab errors. Final mass was too high: Final mass was too low: 5

6 Part V Mass of Dissolved Sugar. Draw particle diagrams representing the ideal data. Before After What should have happened to the mass of the system? Justify your answer. Provide an explanation of possible lab errors. Final mass was too high: Final mass was too low: Part VI Mass of Dissolved Alka-Seltzer. Draw particle diagrams representing the ideal data. Before After What should have happened to the mass of the system? Justify your answer. Provide an explanation of possible lab errors. Final mass was too high: Final mass was too low: 6

7 Unit 1, Worksheet 1 Mass and Change Name: Veritas: 1. When you pulled the steel wool apart in Part 1, you found that the mass was unchanged. When you burned the steel wool in Part 4, you found that the mass changed. Explain. Draw diagrams (at the particle level) of the steel wool before and after the change. Steel wool pulled apart Steel wool - burned Before After Before After 2. When ice melts, the volume of the ice is larger than the volume occupied by the liquid water. How does the mass of the solid water (ice) compare to the mass of the liquid water? Explain. Draw diagrams (at the particle level) of the ice and of the liquid water. Ice Water 3. When the sugar dissolved in the water, we found that the mass remained unchanged. When the Alka-Seltzer dissolved in the water, the mass of the system changed. Explain why there was a difference between the sugar and the Alka-Seltzer. Draw diagrams (at the particle level) of each of the materials before and after it was dissolved. Sugar dissolved in water Alka-Seltzer dissolved in water Before After Before After 4. State the Law of Conservation of Mass in your own words. 7

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9 Unit 1, Lab 2 Title Purpose Question Hypothesis Procedure Data Table Trial Average Conclusion 1. How is volume measured in centimeters related to volume measures in milliliters? 2. Discuss errors in technique that could have affected your data. 9

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11 Chemistry: Measurement Notes Measurement is the collection of quantitative data. The proper handling and interpretation of measurements is essential in chemistry - and in any scientific endeavor. To use measurements correctly, you must recognize that measurements are not numbers. They always contain a unit and some inherent error. Le Systéme Internationale (SI) is a set of units and notations that are standard in science. Here are 4 important SI base units: Quantity SI Base Unit English Equivalent Length Meter (m) 1 m = in Mass Kilogram (kg) 1 kg = 2.2 lbs Time Second (s) Temperature Kelvin (K) F = 1.8( C) + 32 K = C Prefixes are used to adjust the size of base units: Prefix Symbol Size Factor Or nano- n m 10 9 nm 10 9 nm 1m 10 6 µm 1m micro- µ m 10 6 µm milli- m m 10 3 mm 10 3 mm 1m centi- c m 10 2 cm 10 2 cm 1m kilo- k m 1km 1Mm mega- M m 10 3 m 1km 10 6 m 1Mm You must know the following converions: Length Mass Volume 1 km = 1000 m 1 kg = 1000 g 1 kl = 1000 L 100 cm = 1 m 100 cg = 1 g 100 cl = 1 L 1000 mm = 1m 1000 mg = 1 g 1000 ml = 1 L 11

12 Calculations Involving Measurements: Arithmetic with Units Addition and Subtraction: units don t change. 2 kg + 3kg = 5 kg 10 m 1m = 9 m 4.5 g g = 5.7 g Multiplication and Division: units multiple and divide, too. 3m x 3m = 9m 2 5 g / 10 ml = 0.5 g/ml 6 cm 3 / 2 cm = 3cm 2 10 g / 2 g = 5 (units cancel!) 4 cm x 4 cm x 4 cm = 64 cm 3 45 m / 2 m = 22.5 m Converting Units (Dimensional Analysis): 1. Examine the information given, including any units of measurement. 2. Find appropriate conversion factors that can convert from the units given to the desired or requested units. 3. Start with the number and units given in the problem, such as 4.1 cm or 0.38 kg. 4. Align conversion factors so that the units cancel. Multiply your fact with the factor what you want what you have. 5. Multiply the numerators and divide the denominators. The starting units cancel out and you end up with the desired units. Example. Convert 4.1 cm to m. 0.38kg 103 g 1kg 106µg = µg 1g Note: Some conversions require more than one factor; e.g. we do not convert directly from kg to mg. So, the best approach is to convert from kg to g (the base unit) then from g to mg. Example. Convert 0.38 kg to μg. 0.38kg 103 g 1kg 106µg = µg 1g Remember, even though we write factors with x signs, we multiply by the numerators and divide by the denominators. Uncertainty in Measurements When recording a measurement, always read between the lines! - the digit read between the lines is always uncertain - convention: read to 1/10 of the distance between the smallest scale divisions Significant digits are all digits up to and including the first uncertain digit. - the more significant digits, the more reproducible the measurement is. - counts and defined numbers are exact- they have no uncertain digits! Precision of Calculated Results - calculated results are never more reliable than the measurements they are built from - multistep calculations: never round intermediate results! - sums and differences: round result to the same number of decimal places as the poorest measurement - products and quotients: round result to the same number of significant digits as the poorest measurement. Taken from: 12

13 Name: Veritas: Unit 1, Worksheet 2 Reading Scales You most likely did not obtain perfect data when comparing volume units. There are limitations of measurement. The way you report your measurement indicates the quality of your measuring instrument. You will always report your measurements in the appropriate significant figures. You will report all numbers you know for sure (as indicated by markings on the instrument) and the one number you estimate. Directions: For each of the following, write the scale reading, then the number of significant figures in the reading. Reading # SF s

14 Directions: For each of the volume devices below record the scale reading and indicate the uncertainty in the measurement (± ). scale reading uncertainty scale reading uncertainty scale reading uncertainty scale reading uncertainty scale reading uncertainty 14

15 Unit 1, Worksheet 3 Significant Figures and Scientific Notation Name: Veritas: PART 1: Define the type of zero, provide 3 examples of each type of zero, and write the rule for determining significant zeros in the space given below. Sandwiched zeros- Leading zeros- Trailing zeros (decimal present)- Trailing zeros (decimal absent)- PART 2: Underline each significant zero. Write a number in each blank that tells the number of significant figures. 5 EXAMPLE: 750, , , ,000, , , ,000, x x x x x

16 PART 3 DIRECTIONS: Change the following to Standard Scientific Notation with the proper number of significant figures ,500 = = 31. 7,000, ,000,000 = , = = = = PART 4: For each item that is given in Standard Scientific Notation, write it as a number with the proper number of significant figures x 10 5 = x x 10-3 = x x 10 6 = x x 10-5 = x x 10 3 = x x 10-4 = x 10 1 PART 5: Carry out the following calculations. Express each answer in the correct number of significant figures and use the proper units m m m =? ml ml ml =? g g =? kpa x ml =? 35.7 kpa g =? 4.0 cm cm x 21.2 cm x cm =? 16

17 PART 6: Round the following measurements to three significant figures g , 678 m L m m ,000,631 g m L ml cg cm cm 3 PART 7: Work each problem given below. Show all work in the space provided. Report the answer in the blank provided with the correct number of significant figures and with the correct units. 67. A rectangular aquarium is 47.2 cm wide, 89 cm long, and cm tall. What is the volume of the aquarium? How many milliliters of water does it take to fill this aquarium? 68. A crime-scene is roped off with yellow tape. The rectangular area is 5.6 meters long and meters wide. What is the area of the crime scene? PART 8: More calculations! Express each answer in the correct number of significant figures and use the proper units grams grams = grams / 1.1 ml = x 10 3 joules / 34 seconds = meters 0.11 m = cm cm cm = meters / 114 seconds = kilograms kilograms = m/s x s = 17

18 PART 9: Understanding the importance of significant figures. Include sketches of measuring tools to aid in your explanation when necessary. Why are significant figures important when taking data in the laboratory? Why are significant figures NOT important when solving problems in your math class? Using two different instruments, I measured the length of my foot to be 27 centimeters and centimeters. Explain the difference between these two measurements. I can lift a 20 kilogram weight over my head ten times before I get tired. Write this measurement to the correct number of significant figures. Explain. 18

19 Name: Veritas: Unit 1, Worksheet 4 Dimensional Analysis Practice Complete the following unit conversions. Show unit cancellations. Remember to use the appropriate number of SF s in your answer cm x = meters x 10-2 kg x = grams ml x = cm cal x = kilocalories x 10-4 m x = micrometers ml x = liters x 10-1 g x = mg x 10-9 cg x = g x 10 3 mm x = m day x x x = seconds x 10 4 mm x x = km x kg x x = ng mm x x = km 19

20 14. 1 year x x = hours (approximately) cl x x = ml mile x x = inches 17. How many nickels could you trade for 250 yen? $1 = 150 yen. 18. Your school club sold 600 tickets to a chili supper. The chili recipe for 10 persons requires 2 teaspoons of chili powder. How many teaspoons of chili powder will you need altogether? 19. How many cups of chili powder will you need? Three teaspoons (tsp) equal one tablespoon (TBS) and 16 tablespoons equal 1 cup. 20. How many seconds in a year? (assume 30 days in an average month) 21. Chloroform is a liquid once used for anesthetic. What is the volume of 5.0 g of chloroform? The density of chloroform 1.49 g/ml 22. How many inches long is a football field? 23. How many m 3 is 4.6 cm 3.? Express your answer in scientific notation. 24. How many mg is 59.0 kg? Express your answer in scientific notation. 25. How many cm is 356,450 micrometers? Express your answer in scientific notation. 20

21 Name: Veritas: Unit 1, Worksheet 5 More Dimensional Analysis Practice Complete the following unit conversions below each question. Show unit cancellations. Remember to use the appropriate number of SF s in your answer. Part 1: Metric to Metric Conversions centimeters = micrometers x 10-2 kilograms = centigrams milliliters = cm ,470 calories = kilocalories x 10-4 meters = millimeters x 10-2 grams = centigrams x 10-7 milligrams = grams x 10 3 nanometers = millimeters 9. 5 x 10 5 joules = kilojoules x kilograms = micrograms 21

22 Part 2: Conversion Problems 14. How many feet are there in one hundred kilometers? (1 inch = 2.54 centimeters) 16. How many quarters could you trade for 750 yen? (1 U.S. dollar = 120 yen) 17. The school s athletic booster club sold 1,400 tickets for a fundraising chili supper. The chili recipe for 12 persons requires 3 teaspoons of chili powder? How many teaspoons of chili powder will you need altogether to season the chili? 21. How many m 2 is in an area that is exactly 86,000 cm 2? 22. An aquarium has a volume of m 3. How many liters of water are needed to fill the aquarium completely with water. 23. Sarah can study 20 pages per night. Each page has three homework problems. If she studies for 3 nights how many homework problems will she do? 24. On the planet Shnoidia, everyone earns 80 Quatloos a day. One Zerumba (a favorite food item) costs 7 Quatloos. How many Zerumba s can be purchased if someone works for 3 days? 22

23 Unit, 1 Lab 3 Title Purpose/Question Hypothesis Hypothesis Graph (remember: graphs need a title and axes labels) Procedure: 1. Your group will be given either iron or aluminum cylinders. Record which metal you have: 2. For each of the five cylinders, measure the mass and the volume of the cylinder. a. How will you measure the mass? b. How will you measure the volume? (Volume calculations should be shown to the right of the data table. Calculations should be neat, organized, and labeled.) 3. One completed, trade data with a group that had the other metal. Now you should have a data set for both Al and Fe. 4. Using Excel, graph both data sets on the same graph and produce two distinct lines of best fit. Save a copy of the graph in the appropriate google drive folder. File name format should be: Pd#_Group#_Lab1.3 (Fill in your period # and your group #.) Data table: Iron Cylinder # Volume (ml) Mass (g) Aluminum Cylinder # Volume (ml) Mass (g)

24 Post-Lab Questions and Notes 1. Write the equations for both lines (the aluminum line and the iron line) and sketch the graph below. Color-code and label the two lines and the axes. 2. What are the Y-intercepts for each line? Should the y-intercept for each line cross through zero? Justify your answer. 3. Evaluate your y-intercept based on the 5% rule that is shown below. Is your Y-intercept more or less than 5%? Is the Y-intercept negligible or non-negligible? Explain what this tells you. ІyІ ymax x 100 = 4. What specific errors in technique might produce a non-negligible intercept? 5. What is the slope of each line? What is the physical meaning of the slope? State the meaning of both slopes in sentence format. 6. Draw a particle diagram for each substance showing the information you learned from this lab. Explain below. Iron Aluminum 24

25 Name: Veritas: Unit 1, Worksheet 5 Mass, Volume, and Density 1. Study the matter shown in Figure 1. Assume Figure 1 particles of the same size have the same mass. A a. In the table below, show how the masses, volumes, and densities of A and B compare by adding the symbol <, >, or = to the statement in the second column. b. Explain your reasoning for each answer in the last column. FIGURE 1 A B B Property Relationship Reasoning Mass A B Volume A B Density A B 2. Study the matter in Figure 2.. Assume particles of the same size have the same mass. a. In the table below show how the masses, volumes, and densities compare by adding the symbol <, >, or = to the statement in the second column. b. Explain your reasoning for each. FIGURE 2 A C B Property Relationship Reasoning Mass A B Volume Density A C A B A C A B A C 25

26 3. Is object E or object F more dense? [Assume the particles are uniformly distributed throughout each object, and particles with a larger size have a larger mass.] Explain your reasoning. FIGURE 3 E F 4. In Figure 4 to the right, a graph shows the relationship between mass and volume for two substances, A and B. Use the graph to answer questions about these two substances. a) You have built a simple two-pan balance shown above to compare the masses of substances A and B. What would happen to the balance if you put equal masses of A and B in the two pans? Mass (g) FIGURE 4: Mass and Volume Relationships Two Pan Balance Substance A A B Substance B b) What would happen to the balance if you put equal volumes of A and B in the two pans? Explain your reasoning volume (ml) (NOTE: Each box on the x-axis represents 5 ml.) b) Find the slope of the line for both A and B using correct units (show work). Then, state the physical meaning of the slope for each substance. Line A slope: Physical meaning: Line B slope: Physical meaning: c) If you put 10.0 ml of A in one balance pan, how much mass of B would you need in the other pan to make it balance? Explain your reasoning. 26

27 d) If you put 25.0 ml of B in one balance pan, what volume of A would you need in the other pan to make it balance? Explain your reasoning. e) Water has a density of 1.00 g/ml. Sketch the line representing water on the graph in Figure 4. f) Determine whether substance A and B will sink or float when placed in a bucket of water. A: sink float B: sink float (circle correct response) Defend your answer using the m-v graph, and your outstanding understanding of density. Refer to the table of densities at the right to answer the following questions. Substance Density (g/ml) Aluminum 2.70 Titanium 4.54 Zinc 7.13 Tin 7.31 Iron 7.87 Nickel 8.90 Copper 8.96 Silver Lead Mercury Gold Sketch a graph of mass vs. volume for aluminum, nickel, and silver. 6. You made some cubes out of each metal in the table that each measures 4.00 cm on every side. (all except mercury why can t you make a cube of mercury?) a. What is the volume of each cube in cm 3? in ml? (Show your thinking) V = cm 3 V = ml b. Find the mass of these metal cubes: (Show your work below.) tin cube copper cube lead cube 27

28 7. Alicia s cheapskate boyfriend gave her a ring he claims is 24 carat gold. Alicia is skeptical. After chem class the next day she measures the mass of the ring, finds the volume of the ring by water displacement, and then calculates the density of the ring. Should she treasure the ring as his first truly generous gift to her, or should she throw it at him the next time he walks by? Defend your answer by showing the math. DATA: Mass: Initial volume: Final volume: Total volume: Density: g 38.5 ml 40.8 ml 8. A student filled a graduated cylinder with water and read the meniscus at 40.6 ml. The student then dropped a solid metallic material into the graduated cylinder and the water level rose to 44.9 ml. If the solid metal had a density of g/ml, what is the mass of this solid object? What is the identity of this metal? 9. I threw a plastic ball in the pool for my dog to fetch. The mass of the ball was 125 g. What must the volume be to have a density of g/ml? (I want it to float of course!) 10. A little aluminum boat (mass of g) has a volume of cm 3. The boat is placed in a small pool of water and carefully filled with pennies. If each penny has a mass of 2.50 g, how many pennies can be added to the boat before it sinks? 28

29 Name: Veritas: Unit 1, Worksheet 5 Applied Density Problems 1. Determine the density of each metal. Show all your work and include appropriate units. 2. From the graph, estimate a. the mass of 8.0 cm 3 of metal A. b. the volume of 70 g of metal B. c. mark on the graph how you found the answers above 3. Use the density of B as a factor to determine the answer to 2b. Show the set-up including how the units cancel. 29

30 4. Ethanol has a density of g/cm 3. a. What is the mass of 225 cm 3 of ethanol? b. What is the volume of 75.0 g of ethanol? 5. What is the density of water in g/ml? 6. The cup is a volume widely used by cooks in the U.S. One cup is equivalent to 225 cm 3. If 1 cup of olive oil has a mass of 205 g, what is the density of olive oil in g/cm 3? 7. What would you expect to happen if the cup of olive oil in question 6 is poured into a container of ethanol? Why? Gold has a density of 19.3 g/ cm 3. A cube of gold measures 4.23 cm on each edge: 8. What is the volume of the cube? 9. What is its mass? How many significant figures should you include in your answer and why? 10. A standard backpack is approximately 30cm x 30cm x 40cm. Suppose you find a hoard of pure gold while treasure hunting in the wilderness. How much mass would your backpack hold if you filled it with the gold? An average student has a mass of 70 kg. How do these values compare? 30

31 Name: Veritas: Unit 1 Extra Practice Problems 1. What is the difference between mass and volume (in terms of definition, units, and method(s) of measurement)? 2. If the box at left contains atoms of iron in steel wool, represent the atomic structure of the steel wool after burning with a match in the box at right. Next to the particle diagram, explain what occurs when something burns. Explain what happened to the mass of the steel wool as a result. 4. What is the law of conservation of mass? Under what circumstances did mass change in our lab? Explain how mass could change even though the law of conservation of mass states that mass is conserved. 5. The 7th period chemistry class tested the change in mass when sugar was dissolved in water. They concluded that the mass decreases slightly when sugar dissolves. Provide a better explanation based on your knowledge of what should have happened. Questions How many significant figures are in each of the following numbers? x , x ,

32 Solve the following mathematical problems such that the answers have the correct number of significant figures: All answers must have the correct unit m 0.18 m cm cm cm meters / 910 seconds m/s x 20 s 20. The 8 th period chemistry class produced the following graph when they were measuring the mass and volume of a set of objects in the lab. a. Write the equation for the line. b. What is the physical meaning of the slope? c. Is the y-intercept negligible? Why or why not? (Show 5% rule) d. What would you predict would happen if you were to put one of the objects in water? Explain e. What would you expect to be the mass of a 45 cm 3 piece of the same substance? 32

33 Density Problems. Show your work. Show your answer in the correct number of sig figs. No naked numbers. 21. Mercury has a density of 13.6g/mL. What is the volume occupied by grams of mercury? 22. A cube of gold-colored metal with a volume of 54 cm 3 has a mass of 980 g. The density of gold is 19.3 g/cm 3. Is this sample of metal pure gold? Why or why not? 23. A graduated cylinder has 20 ml (cm 3 ) of water placed in it. An irregularly shaped rock is then dropped in the graduated cylinder and the volume of the rock and water in the cylinder now reads 30 ml (cm 3 ). The mass of the rock dropped into the graduated cylinder is 23 grams. a.) Find the volume of the rock dropped into the graduated cylinder. b.) Find the density of the rock dropped into the graduated cylinder. Use the tables below to answer the following questions: Substance Density at 20 C Substance Density at 20 C Wood 0.70 g/cm 3 Rubber 1.34 g/cm 3 Corn oil 0.92 g/cm 3 Corn Syrup 1.38 g/cm 3 Water 1.00 g/cm 3 Copper 8.80 g/cm An object with a mass of 24g and a volume of 32mL is most likely what substance? Justify your answer. 25. What is the only object in the table that would sink in corn syrup? Explain. 26. What is the mass of 100 ml of corn oil? 27. What is the volume of 35g of copper? 33

34 Conversion Problems: Use dimensional analysis to solve each problem. Show your dimensional analysis setup and show how the units cancel. Make sure that the number of significant figures does not change during the conversion. 28. How many feet are there in one hundred kilometers? (1 inch = 2.54 centimeters) 29. How many seconds are there during the month of May? (The month of May contains 31 days.) 30. How many quarters could you trade for 750 yen? (1 U.S. dollar = 120 yen) mg =? g km =? m mm =? cm cm =? mm Measurements and Significant Figures: Below each graduated cylinder, write the correct measurement of water in the appropriate number of significant digits. All cylinders read ml