Chapter 2 Practice Problem Answers & Section Assessment Answers

Practice Problems, pg 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

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

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.

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. 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 It multiplies it by 10 6.

ms/s ms/s 100 cg/g 100 cg/g 10. Oil is less dense than water. 10. Oil is less dense than water cm cm

Section 3 Practice Problem Answers %; 5.66 %; 8.80 % %; 6.29 %; 7.55 % 31. (a.) 4 (b.) 7(c.) 5(d.) (a.) 5(b.) 3(c.) 5(d.) (a.) 84,790 kg (b.) g (c.) cm (d.) m

34. (a.) x g (b.) x 10 5 kg (c.) x 10 8 mm (d.) mL 35. (a.) cm (b.) 768 kg (c.) mg 36. (a.) cm (b.) 2.10 cm (b.) 2.10 cm (c.) 2.7 x 10 3 cm (c.) 2.7 x 10 3 cm

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

The first and second values are very accurate but the third is not. They are not precise %; %; % m because it has the greatest number of significant figures x 10 5 cm

Appendix A Practice Problems Pages mL 2. No, mass A does not equal mass B 3. (a.) x 10 6 m (b.) x 10 2 kg (c.) 5.36 x ng (d.) x km (e.) 3.48 x 10 4 s (f.) x 10 8 cm (g.) x ms (h.) x mL

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

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

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

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

12. (a.) (b.) 3.08 (c.) 5810 (d.) (a.) x (b.) x 10 5 (c.) x10 -4 (d.) x 10 3

14. (a.) (b.) (c.) (d.) 8.00 (d.) 8.00 (e.) (f.) 21.8 (g.) (h.) 4.81 x 10 2

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

Chapter Review, pg The first one; placeholder and The number that has the fewest digits to the right of the decimal point; it is less precise ; it has the smaller number of sig. figs g/mL g/mL mL

75. a.) x mm b.) x g c.) x 10 5 s d.) x 10 9 g d.) x 10 9 g 76. a.) 8,348,000 km b.) 3402 g c.) kg d.) s

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

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

83. a.) 431,800 kg b.) 10,240 mg c.) m d.) cm e.) mL f.) cg f.) cg 84. a.) g b.) 3.88 kg c.) 219,000 m d.) 25.4 L e.) cm f.) mg

85. a.) 7.63 x 10 4 b.) 8.20 x c.) 74.8 dm 3 d.) 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.