PIB Chemistry Chapters 2&3 Practice
Return To Mr. Dull's Home Page Complete questions 1-8 (Mastery = 6/8) 1. The basic unit of mass is the________. 2. 1.0 meter = _______ micrometers 3. 1.0 meter = _________ angstroms 4. The formula used to determine density is___________. 5. Express the number 0.0038404 in scientific notation. 6. How many cm3 are in 2550 ml? 7. What is the density of water? 8. Air is an example of : (a) an element (b) a compound (c) a mixture Complete questions 9-16 (Mastery = 6/8) 9. Which of the following is an example of a chemical change? (a) rotting meat (b) slicing cheese (c) dissolving sugar in ice tea (d) freezing water 10. Which of the following is an example of a heterogeneous substance? (a) element (b) compound (c) mixture 11. A solution may be classified as (a) element (b) compound (c) mixture 12. The melting of ice is an example of a _____________ change. (a) physical (b) chemical (c) nuclear 13. The specific gravity of liquid: (a) is a number without a unit (b) can be determined with a hydrometer (c) is generally the ratio of the density of the liquid to the density of water (d) all of the above 14. The closeness of a measurement to its true value is a measure of its (a) usefulness (b) precision (c) accuracy (d) reproducibility 15. According to the method of significant figures, the number of digits that are estimated in a measurement is (a) one (b) two (c) three (d) none 16. 50 Kelvin's is the same as a Celsius reading of : (a) -223 °C (b) 323°C (c) 223°C (d) 50°C Questions 17-22 (Mastery = 5/6) Determine the correct number of significant figures in the following measurements. (17) 5.370 (18) 0.00425 (19) 340000 (20) 0.000346500 Round of the following measurements to three significant figures. (21) 0.00455390 (22) 499.650 23. List four physical properties of any substance. Complete the following mathematical operations and round off your answers to the correct number of significant figures. Use scientific notation. (24) (2.23 x 109 ) x (6.340x10-3) x (2.564x102)= (Mastery = 2/3) (25) (2.34x1034)x (4.500x10-23) + (2.35x1011) = (26) (2.5x10-1) - (3.4x10-2) = Calculate the answers to problems 26-29. Be sure to label answers and round off to the correct number of significant figures. Use scientific notation. (Mastery =3/4) 27. 75.0 grams of an object has a volume of 50.0 mL . What is the density of the object? 28. How many mL of space will 350.0 g of gold occupy if its density is 19.3 g/cm3? 29. A solution of copper sulfate is mixed with a solution of sodium bicarbonate. A chemical reaction occurs producing four new substances. List any two of the products produced. (Mastery =3/4) 30. A student performs an experiment to determine the density of an object. The 25.0 g object is placed into a graduated cylinder, the volume of the water in the cylinder goes from 51.5 mL to a final volume 64.3 mL. Calculate the density of the object. 31. Devise a way to separate a mixture of sand, sugar charcoal and iron filings into its individual components. 32. Distinguish between physical and chemical changes and give two examples of each. Then, list three things that are often indications of chemical changes. 33. You are hired to count the number of ducks on three northern lakes during the summer. In the first lake, you estimate 500,000 ducks, and in the second 250,000 ducks, and in the third 100,000 ducks. You write down that you have counted 850,000 ducks. Ten minutes later you see 150 ducks fly in from the south and land on the third lake. Do you change the number of ducks that you report? Justify your answer.