1. Solve:

(9.52 x 10⁴) x (2.77 x 10^-5)

(1.39 x 10⁷) x (5.83 x 10²)

2 How many significant figures are in the following?

(a) 5.71 x 10¹³ (b) 4.4 x 10⁶

(c) 3 x 10^-6       (d) 4.000 x 10^-11

(e) 5.5550 x 10^-3

3 Multiply these numbers, using the correct number of significant figures in your answer:

(a)3630.15 x 6.8

(b) 512 x 0.0081

(c) 5.79 X 1.85825 x 1.4381

4 For each of these, tell which figure is closest to the  correct answer:

(a) A baseball bat has a length of 100 mm or 100 cm or 100 m

(b) A glass of milk holds 23 cc or 230 mL or 23 L

(c) A man weighs 75 mg or 75 g or 75 kg

(d) A tablespoon contains 15 mL or 150 mL or 1.5 L

5. Make the following conversions (conversion factors are given in Table 1.3):

(a) 42.6 kg to lb                    (b) 1.62 lb to g

(c) 34 in. to cm                      (d) 37.2 km to mi

(e) 2.73 gal to L                     (f) 62 g to oz

(g) 33.61 qt to L                    (h) 43.7 L to gal

(i) Ll mi to km                       (j) 34.9 mL to fl oz

6 Classify each of the following as a chemical or physi­cal change:

(a) Burning gasoline

(b) Making ice cubes

(c) Boiling oil

(d) Melting lead

(e)Rusting iron

(f) Making ammonia from nitrogen and hydrogen

(g) Digesting food

7. Write out in full:

(a) 4.03 x 10⁸        (b) 3.2 x 10³

(c) 7.13 x 10^-5       (d) 5.55 x 10^-10

8. Multiply:

(a) (2.16 x 10⁸) (3.08 x 10¹²)

(b)(1.6 x 10^-8) (7.2 x 10⁸)

(c) (5.87 x 10¹⁰) (6.6 x 10^-27)

(d)(5.2 x 10^-9) (6.8 x 10^-18)

9. Divide:

(a) 6.02 x 1023                           (b) 3.14

2.87 x 10¹⁹                              2.93 x 10^-4

(c)                                          (d)

5.86 x 10^-9                            7.8 x 10^-12

2.00 x 10³                               9.3 x 10^-H

(e) 6.83 x 10^-12

5.02 x 1014

10. Your car gets 25.00 miles on a gallon of gas. What would be your car's fuel efficiency in km/L?

11. The recommended pediatric dosage of Velosef is '^se. 20. mg/kg/day. What is the daily dose in mg for a child weighing 36 pounds? If the stock vial of Velosef is labeled 208 mg/mL, how many mL would be given in a daily dose?

12. The density of methanol at 20°C is 0.791 g/mL. ^as What is the mass, in grams, of a 280 mL sample?

13. You are waiting in line in a coffee shop. As you look at the selections, you see that the decaffeinated coffee is labeled "chemical-free." Comment on this label in light of the material in Section 1.1.