1 / 12

More on “Signal”

More on “Signal”. Interference Method blank Matrix effect Detection limit. The “Scales” of Analytical Chemistry. Review Significant Figures. What are sig figs? Rules: Addition/subtraction Multiplication/division Log/antilog Exact numbers When to round?. Significant Figures Examples.

cais
Download Presentation

More on “Signal”

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. More on “Signal” • Interference • Method blank • Matrix effect • Detection limit

  2. The “Scales” of Analytical Chemistry

  3. Review Significant Figures • What are sig figs? • Rules: Addition/subtraction Multiplication/division Log/antilog Exact numbers • When to round?

  4. Significant Figures Examples • Add the numbers 1.0556, 7.113*10-2, and 0.81 • How many kilometers is 9.3 miles? (Use the conversion factor 1 km = 0.62137 mi.) • A student measures the mass and volume of a liquid to determine its density. The volume is 25.00 mL. An empty beaker has a mass of 74.881 g, and the beaker with liquid is 99.437 g. What is the density? • What is the pH of a 1.56*10-3 M hydrochloric acid solution?

  5. Accuracy • What is accuracy? • Quantifying accuracy • Assessing accuracy • No true value?

  6. Precision • What is precision? • Quantifying precision • Assessing precision

  7. Characterizing Data Example Calculate the average, mode, standard deviation, relative standard deviation, and percent relative error for the following data set (density of pennies, post 1982 = 7.18 g/mL). (By hand first, then use your calculator’s stat mode…) • 7.22 g/ml • 6.87 g/ml • 7.03 g/ml • 7.30 g/ml

  8. Two Types of Error • Determinate error • Sampling • Method • Measurement • Personal **can be constant or proportional**

  9. Class A Tolerances

  10. Two Types of Error • Indeterminate/random Visualizing these: Determinate Indeterminate

  11. Uncertainty • What is uncertainty? • DUI example

  12. If you don’t learn anything else in this class…

More Related