CHEM 1001/CHM1020/CHM1025C/CHM1032C Name:___________

Module Two: ChemMath and Measurement (Corwin Chapters 2 & 3)

A. _____(03) Significant Figures- Section 2.2 Answers abc

B. _____(03) Round Off/Math of Significant Figures- Section 2.3 Answers abc

C. _____(04) Scientific Notation Section 2.6 Answers abc

D. _____(10) Metric Basic Units /Numerical Prefixes- Section 3.1 Answers de

E. _____(10) Metric System Conversion Factors- Section 3.2-3.3 Answers de

F. _____(10) Unit Analysis Sections 2.8, 2.9, 3.4 Answers fg Pretest #2 Ans2

G. _____(10) Temperature Conversion Section 3.8 Answers gh

H. _____(10) Density/Specific Gravity Calculations Section 3.7 Answers gh

M _____(10) Multiple Choice (Measurement) Chapter 2&3

_______(70) Total = ______%

Module Two: Sample Pretest

Module Two-Part A: Significant figures (1.7) 3 points ANSWERS

In the blank, state the number of significant figures in each of the following measurements:

__1__1. 0.05 mL ___1__4. 1000 g

__4__2. 250.0 cm ___4__5. 0.00006500 moles

__3__3. 456,000,000 people __3___6. 0.00200 kg

Module Two-Part B: Rounding Off & Arithmetic Operations of Sign. Figures 3 points

Round off the following numbers to three significant figures:

(1) 1.598 x 10⁶= _1.60 x 10⁶__ (2) 0.000 000 484 500 = ___4.85 x 10 ^-7____

Perform the following addition/multiplication operations and express the answer using the proper units and significant figures:

(3) 4 mL (4) 16.5 cm (5) 12.0 g ÷ 1.00 g = 12.0

16.3 mL X 1.7 cm or

+ 0.953 mL 28 cm² 12.0 g / 1.00 g = 12.0

21 mL

Module Two-Part C: Exponential Numbers and Scientific Notation 3 points

(1.6 & 1.&) Express the following ordinary numbers in scientific notation (If greater than three significant figures, round off to three significant figures:

(1) 1,010,100,000,000, 000 = _1.01 x 10 ¹⁵_ (4) 0.0001198 = _1.20 x 10 ^-4___

(2) 0.000 000 000 000 019 = _1.9 x 10 ^-14_ (5) 1,000,000 = __1 x 10 ⁶______

(3) 456,789 = __4.57 x 10 ⁵_ (6) 0.000200 = __2.00 x 10 ^-4___