C. Review Questions and Practice Problems

The following is an example of the completed review and practice problem set. The completed assignment is parent corrected or student self-correct by the due date indicated in your Course Schedule. Your student’s completed assignment document should be handwritten or typed and saved in your student’s notebook. The review and practice problem assignment, the On Your Own questions, the practice test that is your Solutions Manual, the lecture notes, and the text itself are all sources of Module Test and Exam questions:

As per Red Wagon Tutorials policy, any assignment completed is assumed to be supervised and proctored by the student's parent. The example follows:

Mr. Chris Chemistry
Honors Chemistry
Module 1 Review and Problem Set

Review Questions: Please be sure to answer all the review questions as complete sentences.

1. Matter is defined as anything that has mass and takes up space. Pretty much everything except light contains matter. Since (d) is the only thing on the list that is just light, the lightning bolt (d) has no matter.

2. In the metric system, length is measured in meters, mass is measured in grams, time is measured in seconds, and volume is measured in liters.

3. The metric system prefix “centi” means 0.01, or one hundredth.

4. Since a kL is equal to 1,000 L and a mL is only equal to 0.001 L, the glass holding 0.5 kL has more liquid in it. 500 L is clearly more than 120 mL.

5. The ruler is marked off in 0.1 cm. You can estimate to the next decimal place. Since the end of the ribbon falls between 2.6 cm and 2.7 cm, the best answer is 2.65 cm. Answers from 2.63 to 2.67 could be counted correct as well.

6. Two students measure the mass of a 502.1 gram object. The first student measures the mass to be 496.8123 grams. The second measures the mass to be 501 grams. Assuming both students reported the proper number of significant figures, the first student was more precise (because that measurement has more places to the right of the decimal), but the second student was more accurate (because that measurement is closer to the correct value).

7. The significant figures given are as follows:

a. The first two zeros are not significant, but the other two are. Thus, there are 6 significant figures.

b. All of the zeros are significant. Thus, there are 5 significant figures.

c. There are 2 significant figures.

d. The zero is significant. Thus, there are 3 significant figures.

8. The mass of the object as 2.32 grams and its volume is 34.56 mL. The object’s density is equal to 0.0671 g/mL. The student’s value for density has far too many significant figures, and it has no units attached. Either of these things would make the student’s answer wrong.

9. Ice floats on water because its density is lower than that of water.

10. Lead has a density of 11.4 grams per mL, whereas gold has a density of 19.3 grams per cc. cc and mL are exactly the same thing. There are 1000 mL in 1L by definition. Also 1 L = 1 dm x 1 dm x 1 dm, but 1 dm =10 cm, so 1 L = 1000 cm ³, thus 1 mL = 1 cm³ (= 1 cc). 19.3 grams per cc is more dense than 11.4 grams per mL. The golden statue would be heavier because the density of gold is greater than that of lead.

Practice Problems: Be sure to show ALL the sets and display the proper units in your answers.

1.

2.

3.

4.

5.

6.

7. a. This is a big number, so the exponent needs to be positive. To get the decimal next to the first digit, we have to move it two places. The answer, then, is 1.2345 x 10².

b. This is a small number, so the exponent has to be negative. The decimal point needs to be moved four places to get to the right of the first digit. The answer, then, is 3.040 x 10^-4. Note that the last zero must be there, as it is significant in the original number.

c. This is a big number, so the exponent is positive, and the decimal must be moved six places to get it next to the first digit. Thus, the answer is 6.1 x 10⁶. Note that I dropped the zeros in the original number, because none of them are significant.

d. This number is small, so the exponent is negative, and the decimal need be moved only one place. The answer, then, is 1.234 x 10^-1.

8. a. A positive exponent tells us to make this a big number by moving the decimal 3 places, so the answer is 6,540. The zero is not significant, so this number has the same significant figures as the original number.

b. A negative exponent means to make the number small by moving the decimal 3 places, so the answer is 0.003450. The last zero must be there, as it is significant in the original number.

c. A positive exponent tells us to make this a big number by moving the decimal 7 places, so the answer is 35,600,000. The zeros are not significant, so this number has the same significant figures as the original number.

d. A negative exponent tells us to make the number small by moving the decimal 7 places, so the answer is 0.0000004050. The last zero must be there, as it is significant in the original number.

9.

10.