This preview shows pages 1–10. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Chemical Measurements C125 Prelab C125 Exp er im en tal Che m i st ry 1 Purpose Investigate what is meant by: Precision Accuracy Determine the density of water: Differences in various pieces of glassware Analyzing error of glassware Important Terms for This Experiment Aliquot Significant digits/figures Density Accuracy % error Uncertainty Precision Standard deviation Definition of Aliquot The portion of the measurement added The amount of the substance that is to be measured that is added to the collection vessel In this experiment, we will be using an aliquot of 10ml of water for each trial Definition of Significant Figures The number of meaningful digits in a measured or calculated quantity Digits beyond the significant figures are due to systematic and random error of the glassware that you are using and your technique when using that glassware The last digit is understood to be the digit of uncertainty in the measurement Rules for Significant Figures Any nonzero digit in a measurement is significant Zeros between nonzero digits are significant Zeros to the left of the 1 st nonzero digit are insignificant Zeros to the right of the last nonzero digit are significant Rules for Rounding Wait until the end of the calculation to round to the appropriate amount of significant figures If the digit removed is more than 5 increase the preceding number If the digit removed is less than 5 do not change the preceding number If the digit removed is 5: Increase preceeding number if it is odd Do not change the preceeding number if it is even Calculation Rules for Significant Digits/Figures Adding/Subtracting Answer cannot have more digits to the right of the decimal point than either of the original numbers 2.097 0.12 = 1.977 Because the 2 nd number only goes to the hundreths place, the answer is 1.98 Calculation Rules for Significant Digits/Figures Multiplying/Dividing...
View Full
Document
 Fall '08
 STAFF
 Chemistry

Click to edit the document details