1. Chapter 2 Practice Problem Answers & Section Assessment Answers

2. Practice Problems, pg. 20 1. m = 147 g 1. m = 147 g v = 41 – 20 = 21 mL v = 41 – 20 = 21 mL D = ? D = ? D = 147 g D = 147 g 21 mL 21 mL D = 7.0 g/mL D = 7.0 g/mL

3. 2. v = ? 2. v = ? m = 20 g D = 4 g/mL D = 4 g/mL 4 = 20 4 = 20 v 4v = 20 4v = 20 V = 5 mL V = 5 mL

4. 3. m = 20 g 3. m = 20 g v = 5 cm 3 v = 5 cm 3 D = ? D = ? D = 20 g D = 4 g/cm 3 D = 20 g D = 4 g/cm 3 5 cm 3 5 cm 3 No, the density of Al is 2.7 g/cm 3, as stated in the example problem. The density of this cube is 4 g/cm 3, so it cannot be Al.

5. Section 2.1 Assessment 4. length: meter 4. length: meter mass: kilogram mass: kilogram time: second time: second temperature: kelvin temperature: kelvin 5. Density is the mass-to-volume ratio of a material. (How much stuff is packed into a given space.) 5. Density is the mass-to-volume ratio of a material. (How much stuff is packed into a given space.)

6. 6. B and C 6. B and C B, 12g/4cm 3 = 3 g/cm 3 B, 12g/4cm 3 = 3 g/cm 3 C, 33g/11mL = 3 g/mL C, 33g/11mL = 3 g/mL A = 80g/20mL = 4 g/mL (not the same) A = 80g/20mL = 4 g/mL (not the same) 7. Base unit definitions are based on a physical object or process. Derived units use a combination of base units. 7. Base unit definitions are based on a physical object or process. Derived units use a combination of base units. 8. It multiplies it by 10 6. 8. It multiplies it by 10 6.

7. 9. 1000 ms/s 9. 1000 ms/s 100 cg/g 100 cg/g 10. Oil is less dense than water. 10. Oil is less dense than water. 11. 100 cm 11. 100 cm

8. Section 3 Practice Problem Answers 29. 11.9 %; 5.66 %; 8.80 % 30. 6.92 %; 6.29 %; 7.55 % 31. (a.) 4 (b.) 7(c.) 5(d.) 3 32. (a.) 5(b.) 3(c.) 5(d.) 2 33. (a.) 84,790 kg (b.) 38.54 g (c.) 256.8 cm (d.) 4.936 m

9. 34. (a.) 5.482 x 10 -4 g (b.) 1.368 x 10 5 kg (c.) 3.087 x 10 8 mm (d.) 2.014 mL 35. (a.) 142.9 cm (b.) 768 kg (c.) 0.1119 mg 36. (a.) 12.12 cm (b.) 2.10 cm (b.) 2.10 cm (c.) 2.7 x 10 3 cm (c.) 2.7 x 10 3 cm

10. 37. (a.) 78 m 2 (b.) 12 m 2 (c.) 2.5 m 2 (d.) 81.1 m 2 38. (a.) 2.0 m/s (b.) 3.00 m/s (c.) 2.00 m/s (d.) 2.9 m/s

11. 39. 4 40. The first and second values are very accurate but the third is not. They are not precise. 41. 0.01307 %; 0.02615 %; 0.1307 % 42. 8.1956 m because it has the greatest number of significant figures 43. 5.06000 x 10 5 cm

12. Appendix A Practice Problems Pages 871-872 1. 4.0 mL 2. No, mass A does not equal mass B 3. (a.) 5.453 x 10 6 m (b.) 3.008 x 10 2 kg (c.) 5.36 x 10 -3 ng (d.) 1.20325 x 10 -2 km (e.) 3.48 x 10 4 s (f.) 3.3208 x 10 8 cm (g.) 2.383 x 10 -4 ms (h.) 3.048 x 10 -1 mL

13. 4. (a.) 8 x 10 2 (b.) 1.2 x 10 -4 (b.) 1.2 x 10 -4 (c.) 2.98 x 10 6 (c.) 2.98 x 10 6 (d.) 6.01 x 10 -2 (d.) 6.01 x 10 -2 (e.) 1.08 x 10 2 (e.) 1.08 x 10 2 (f.) 1.36 x 10 -3 (f.) 1.36 x 10 -3 (g.) 6.791 x 10 5 (g.) 6.791 x 10 5 (h.) 8.691 x 10 -2 (h.) 8.691 x 10 -2

14. 5. (a.) 8 x 10 8 (b.) 8 x 10 6 (c.) 1.5 x 10 2 (d.) 9 x 10 -6 (e.) 2 x 10 1 (f.) 3 x 10 -2 (g.) 2 x 10 2 (h.) 4 x 10 -7

15. 6. (a.) 9.6 x 10 4 (b.) 1.55 x 10 -1 (c.) 1.5 x 10 -4 (d.) 5.84 x 10 -4 (e.) 1.88 x 10 1 (f.) 3.6 (g.) 2.4 x 10 13 (h.) 8.5 x 10 8

16. 9. 5.99 %; 4.63 %; 3.81 % 10. 3.91 %; 2.34 %; 2.34 % 11. (a.) 6 (b.) 2 (c.) 3 (d.) 8 (d.) 8 (e.) 4 (f.) 3 (g.) 4 (h.) 3

17. 12. (a.) 0.00308 (b.) 3.08 (c.) 5810 (d.) 34.6 13. (a.) 5.832 x 10 -3 (b.) 3.86808 x 10 5 (c.) 5.800 x10 -4 (d.) 2.086 x 10 3

18. 14. (a.) 103.8 (b.) 0.167 (c.) 705.2 (d.) 8.00 (d.) 8.00 (e.) 2.223 (f.) 21.8 (g.) 462.9 (h.) 4.81 x 10 2

19. 15. (a.) 410 (b.) 0.021 (c.) 604 (d.) 2.94 (d.) 2.94 (e.) 1.426 (f.) 15.3

20. Chapter Review, pg. 50 - 51 65. The first one; placeholder 66. 3.448 and 3.450 67. The number that has the fewest digits to the right of the decimal point; it is less precise 68. 3.72; it has the smaller number of sig. figs 72. 1 g/mL 73. 1.5 g/mL 74. 3.0 mL

21. 75. a.) 4.5384 x 10 -3 mm b.) 3.054 x 10 -2 g c.) 4.38904 x 10 5 s d.) 7.0043 x 10 9 g d.) 7.0043 x 10 9 g 76. a.) 8,348,000 km b.) 3402 g c.) 0.0076352 kg d.) 0.0000302 s

22. 78. a.) 9.6 x 10 8 km 2 b.) 9.99 x 10 -9 m 2 b.) 9.99 x 10 -9 m 2 c.) 1.8 x 10 -1 m 2 c.) 1.8 x 10 -1 m 2 79. a.) 1 kg/10 3 g b.) 10 3 g/1 kg c.) 10 -3 m/1 mm

23. 80. (a.) 5.70 x 10 3 (b.) 0.0437 (b.) 0.0437 (c.) 783,000 (c.) 783,000 (d.) 0.0453 (d.) 0.0453 (e.) 1000 (e.) 1000 (f.) 37.5 (f.) 37.5 81. (a.) 5.5% (b.) 0% (c.) 3.6% (d.) 7.3% 82. (a.) 1.12% (b.) 0.446% (c.) 0.446% (d.) 0.223%

24. 83. a.) 431,800 kg b.) 10,240 mg c.) 1.035 m d.) 0.004384 cm e.) 0.0007810 mL f.) 0.009864 cg f.) 0.009864 cg 84. a.) 0.00321 g b.) 3.88 kg c.) 219,000 m d.) 25.4 L e.) 0.0876 cm f.) 0.00311 mg

25. 85. a.) 7.63 x 10 4 b.) 8.20 x 10 -3 c.) 74.8 dm 3 d.) 13.82 cm 86. a.) mercury b.) wood c.) iron d.) lead 87. Graph should show a straight line with a slope of 2.7 g/mL.