Most exercises in CHE 133 - 134 involve the replicate determination of some measurable quantity. The number of repetitive measurements is usually small (3 - 5 determinations). We invoke simple statistical concepts in the reporting of the results of such m
1. Diameter of Sphere and Computation of its Area and Volume
The area of a sphere of radius, r, is given by A = 4 r2. The volume, by (4/3) r3 . Since the diameter, d, is twice the radius, ( d = 2 r )we can rewrite the above as: A = d2 3 and V = (1/6) d Su
More sophisticated ways exist to handle uncertainties in quantities than significant figures. [For an extensive discussion, see the NIST website on Uncertainty of Measurement Results.] However, using this relatively simple formalism should create a sensit
Why Weigh by Difference?
The amounts of solid samples weighed in this course are generally small. I.e., often 500 mg or less. Analytical balances can weigh objects with a precision of about 0.2 mg.
For a 500 mg sample, this is 100 x 0.2 / 500 = 0.04 %
Today's Pre-Lab Lecture Who is who? What do you need to buy?
Last Update: 8/31/2009 7:45 PM
Who's Who Labs / Lectures Prof. Robert Schneider, Fri Pre-lab Lecture & Secs 2 & 4 Dr. Hasan Yumak, Coordinator of Laboratories Mon Pre-lab Lecture & Secs 3,
Measuring devices have intrinsic uncertainty Measurement process itself may introduce
i.e., limitations due to their design/construction
Introduction to Laboratory Measurement SUSBSUSB-003
Last Updated: 9/2/2009
READ SUSB 001 & SUSB002
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MEASURE WEIGH SPHERE SPHERE WHICH BALANCE COMPUTE BEST VOLUME WEIGHT COMPUTE DENSITY ANALYZE ERRORS
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