1 / 12

Math in Chemistry

Math in Chemistry. Just a little bit. Scientific notation. Complete the chart below. Decimal notation. Scientific notation. 127. 0.0907. 5.06 x 10 – 4. 2.3 x 10 12. How do you know when to round a number?. In science we describe a value as having a certain number of “significant digits”

vartan
Download Presentation

Math in Chemistry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Math in Chemistry Just a little bit

  2. Scientific notation Complete the chart below Decimal notation Scientific notation 127 0.0907 5.06 x 10–4 2.3 x 1012

  3. How do you know when to round a number? • In science we describe a value as having a certain number of “significant digits” • The # of significant digits in a value includes all digits that are certain plus one that is estimated • There are rules to determine which numbers are significant

  4. Rule #1 • All non-zero numbers are significant 284 has ____ sig figs 123,456 has _____ sig figs

  5. Rule #2 • Included zeroes (between non-zero digits) are significant 2008 has _____ sig figs 108 has _____ sig figs 50000000001 has ____ sig figs

  6. Rule #3 • Trailing zeroes (those at the end) are never significant unless a decimal is shown 90000 has 1 sig fig 900.00 has 5 sig figs 120000 has ____ sig figs 500.00 has ____ sig figs

  7. Rule #4 • Leading zeroes (to the left of the first non-zero number) are not significant…they are only placeholders 0.00000485 has ____ sig figs 0.052 has ___ sig figs

  8. How many Sig Figs? • 2.83 • 36.77 • 14.0 • 0.0033 • 0.02 • 0.2410 • 2.350 x 10–2 • 1.00009 • 3 • 0.0056040

  9. Practice Counting Sig Figs

  10. Round to the correct number of Sig Figs: Addition & Subtraction a) b) c) 83.25 4.02 0.2983 – 0.1075 + 0.001 + 1.52 When Adding or Subtracting, the lowest number of decimal places used determines where to round your final answer.

  11. Round to the correct number of Sig Figs: Multiplication & Division i) 7.255  81.334 = 0.08920 ii) 1.142 x 0.002 = 0.002 iii) 31.22 x 9.8 = 3.1 x 102 or 310 iv) 6.12 x 3.734 + 16.1  2.3 = 22.85208 + 7.0 = iiv) 146.1  6.487 = The fewest number of sigfigs used in the calculation determines the number of sigfigs in your answer.

  12. On your own paper, write and complete the following calculations. Round your answers to the correct number of sig figs. 1.) 7846 X 92437  X 235.649 X 3300= 2.) 583.00 ÷ 83= 3.) (57.6 X 3) ÷ (34 X 3.00 X 87.507)= 4.) 78.00 + 45.6 + 0.00467 + 39.45 + 276.999= 5.) 567.000 - 12= 6.) 8597 - 0.1 = 7.) (3.50 X 105)  X [2.8 ÷ (5.4  - 4.09)]= 8.) (6.10 X 107 ) + (3 X 107 )= 9.) 787  X 3.0= 10.) (23.5-21.3) ÷ 1.58=

More Related