1. I II III Welcome to Chemistry 116!

2.  Work to be turned in will only be accepted during the first 10 minutes of lab, or will be considered late  Work Later then one week will not be accepted, unless approved by me.  If absent from lab 20 point deduction from the lab write up, you can complete the pre-lab questions and post lab questions for credit  More then two absences, you will automatically drop a grade  At the end of the lab, all materials need to be put away lab benches cleaned or 10 points will be deducted per lab Grading Policy

3. Grades  Short quiz worth 10 points  lab report will include data, graphs and calculations worth 20 points  Post lab questions worth 10 points.  Practical exam will be given at the end of the semester worth 100 points.

4. How to print out notes  Go to file, click on print, look for print what change from slides to handouts; then adjust how many you want per page.  Also change color to pure black & white.

5. I II III I. Using Measurements CH. 1 - MEASUREMENT

6. B. Percent Error  Indicates accuracy of a measurement your value book value

7. B. Percent Error  A student determines the density of a substance to be 1.40 g/mL. Find the % error if the accepted value of the density is 1.36 g/mL. % error = 2.9 %

8. C. Significant Figures  Indicate precision of a measurement.  Recording Sig Figs  Sig figs in a measurement include the known digits plus a final estimated digit 2.35 cm

9. C. Significant Figures  What you see + a guess. 6.63 ml

10. C. Significant Figures  Counting Sig Figs  Count all numbers EXCEPT:  Leading zeros -- 0.0025  Trailing zeros without a decimal point -- 2,500

11. 4. 0.080 3. 5,280 2. 402 1. 23.50 C. Significant Figures Counting Sig Fig Examples 1. 23.50 2. 402 3. 5,280 4. 0.080 4 sig figs 3 sig figs 2 sig figs

12. C. Significant Figures  Calculating with Sig Figs  Multiply/Divide - The # with the fewest sig figs determines the # of sig figs in the answer. (13.91g/cm 3 )(23.3cm 3 ) = 324.103g 324 g 4 SF3 SF

13. C. Adding or subtracting Significant Figures  The result has the same number of decimal places as the measurement with the of decimal places. 3.75 mL + 4 mL 7 mL 22.4 g + 13.500 g 35.9 g

14. C. Significant Figures  Calculating with Sig Figs (con’t)  Exact Numbers do not limit the # of sig figs in the answer.  Counting numbers: 12 students  Exact conversions: 1 m = 100 cm  “1” in any conversion: 1 in = 2.54 cm

15. C. Significant Figures 5. (15.30 g) ÷ (6.4 mL) Practice Problems = 2.390625 g/mL  18.1 g 6. 18.9g - 0.84 g 18.06 g 4 SF2 SF  2.4 g/mL 2 SF

16. D. Scientific Notation  Converting into Sci. Notation:  Move decimal until there’s 1 digit to its left. Places moved = exponent.  Large # (>1)  positive exponent Small # (<1)  negative exponent  Only include sig figs. 65,000 kg  6.5 × 10 4 kg

17. D. Scientific Notation 7. 2,400,000  g 8. 0.00256 kg 9.7  10 -5 km 10.6.2  10 4 mm Practice Problems 2.4  10 6  g 2.56  10 -3 kg 0.00007 km 62,000 mm

18. D. Scientific Notation  Calculating with Sci. Notation (5.44 × 10 7 g) ÷ (8.1 × 10 4 mol) = 5.44 EXP EE ÷ ÷ EXP EE ENTER EXE 78.1 4 = 671.6049383= 670 g/mol= 6.7 × 10 2 g/mol Type on your calculator:

19. E. Proportions  Direct Proportion  Inverse Proportion y x y x

20. Lab Part A on page 11  A Length of book correct sig figs- measure in Cms and convert into mm, m, and inches Show all work Determine area of book

21. Lab Part B on page 11  Graduated cylinder  Large test tube correct sig figs- measure in mls

22. Due next week  Prepare for quiz  Wst on measurements 1