Wrap-Up

That brings us to the end of Lesson 1. I recommend that you go back over the assumptions and objectives and be sure that you can do each one of them. Also, take the self-quiz for the lesson to give yourself some practice answering questions on this material. The self-quiz is posted here and also in your workbook at the end of the lesson. The answers to the self-quiz are available here for you to check your answers.

You should have had all your questions on this lesson answered in one way or another as you went through the lesson. But if, for some reason, there are still some things that are puzzling to you, be sure to check with the instructor to get all of those things squared away before you decide that you are done with the lesson.

There is also a set of practice problems (for additional practice on significant digits and scientific notation) here and in your workbook for your practice.

Practice Problems

1. Give the number of significant digits in each of the following

2050 0.4909 15.8 0.0000763 1.00 x 10⁴

2. Express each number in proper scientific notation

0.362 10570 1.937 0.002910

3. Perform the following conversions--use 3 significant digits

15.0 mm = __ cm 7.80 mL = __ L 0.0792 km = __ m

0.0462 L = __ mL 0.137 g = __ mg

4. Express the answers to these to the proper number of significant digits:

14*5.39 0.000685/0.7210 17.0*3.55/3 5.00 + 0.0189 0.08070 - 0.0041

5. Express the answers to these in scientific notation and to two significant digits:

(2.1 x 10³) (3.5 x 10^-8) 9.4*10⁷/2.0*10⁸ 3.3*10⁴/4.2*10^-4

3.0*10²¹ * 2.0*10^-14/4.5*10^-12 4.5*10² + 1.91*10³

Practice Problem Answers

1. 3, 4, 3, 3, 3.

2. 3.62 x 10^-1 , 1.057 x 10⁴ ,1.937 x 10⁰, 2.910 x 10^-3

3. 1.50 cm, 0.00780 L, 79.2 m, 46.2 mL, 137 mg

4. 75., 9.50 x 10^-4 , 2 x 10¹, 5.02, 0.0766

5. 7.4 x 10^-5, 4.7 x 10^-1, 7.9 x 10⁷, 1.3 x 10¹⁹, 2.4 x 10³

Self Quiz

Give your answers to the proper number of significant digits when appropriate. *Note: To get the most benefit from the self quiz, take it as though you are actually taking the quiz in class -- put away your notes and workbook and use only your calculator and your memory. If you can't answer a question, or are just guessing, then make a note of those questions and go back and review those sections.

1. A property of a material which does not depend on how much of the material

you have is called an ________ property.

a. extrinsic

b. intrinsic

2. 5.300 g/3.10 mL =

a. 2 g/mL

b. 1.7 g/mL

c. 1.7097 g/mL

d. 1.71 g/mL

e. 1.710 g/mL

3. Which of the following is an appropriate measurement for an electronic balance of the type we have in our lab?

a. 4 g

b. 4.3 g

c. 4.31 g

d. 4.312 g

e. 4.3123 g

4. Use the following data to calculate the density of the metal:

Volume of water in cylinder without metal 7.0 ml

Volume of water in cylinder with metal 9.0 ml

Mass of cylinder and water without metal 32.0 g

Mass of cylinder and water with metal 40.0 g

a. 0.25 g/ml

b. 0.89 g/ml

c. 4.0 g/ml

d. 4.4 g/ml

e. 10 g/ml

5. What is the volume of an object having a density of 2.0 g/ml and a mass of 5.0 g?

6. 25 cm =

a. 0.025 m

b. 0.25 m

c. 2.5 m

d. 250 m

e. 2500 m

7. Change 3.0 x 10⁶ mm into meters.

a. 3.0 x 10⁹

b. 3.0 x 10⁶

c. 1.0 x 10⁶

d. 3.0 x 10³

e. 1.0 x 10³

8. Which is larger: 1/2 gallon or 2 liters? (NOTE: 1.00 quart = 946 ml)

a. 1/2 gallon

b. 2 liters

9. Chemists measure volume using this unit:

a. meter

b. centimeter

c. milliliter

d. gram

e. ounce

Self Quiz Answers

Here are the answers to the Lesson 2 Self-Quiz.

1. A property of a material which does not depend on how much of the material

you have is called an ________ property.

*b. intrinsic

2. 5.300 g =

3.10 mL

*d. 1.71 g/mL

3. Which of the following is an appropriate measurement for an electronic balance

of the type we have in our lab?

*d. 4.312 g

4. Use the following data to calculate the density of the metal:

Volume of water in cylinder without metal 7.0 ml

Volume of water in cylinder with metal 9.0 ml

Mass of cylinder and water without metal 32.0 g

Mass of cylinder and water with metal 40.0 g

*c. 4.0 g/ml

5. What is the volume of an object having a density of 2.0 g/ml and a mass of 5.0 g?

2.5 ml

6. 25 cm =

*b. 0.25 m

7. Change 3.0 x 10⁶ mm into meters.

*d. 3.0 x 10³

8. Which is larger: 1/2 gallon or 2 liters? (NOTE: 1.00 quart = 946 ml)

*b. 2 liters

9. Chemists measure volume using this unit:

*c. milliliter