Chemistry 9-11 LAB Good

Eddy Egan September 21, 2007 Paolilo Day 2 Pd. 8/9 Uncertainty in Measurement Purpose: T o fine what factors determine the uncertainty of a measurement Materials and Procedure in Chemistry Connections to Our Changing World pg. 48 using electronic balances Date Performed: September 19, 2007 Instrument Measurement Results Uncertainty Triple-Beam Ba la nc e Ma ss of Co in 5.73 g 5.71 g 5.71 g 5.72 + .01 Centimeter Ruler Length of Paper 14.2 cm 14.2 cm 14.2 cm 14.2 + 0.0 Width of Paper 11.00 cm 10.90 cm 10.90 cm 10.9 + 0.0 Ce ls ius Thermome te r T empe ra ture of Air 23. 0 ºC 24.5 ºC 23.5 ºC 23.7 + .556 Graduated Cylinder Volume of Water 68.0 mL 68.0 mL 68.0 mL 68.0 + 0 How precise were your measurements? Our measurements were fairly accurate with only a slight uncertainty placed on three of the five experiments. The inaccurate readings can be accounted for by human error in the centimeter ruler experiment, a change in the temperature of the Celsius thermometer experiment and possibly air speed over the electronic balance as people were hovering about it and breathing on it. In all the experiments came out much expected and we have learned from any mistakes we may have encountered along the way. 1. Which instrument would be more accurate for measuring the volume of a liquid- a beaker or a graduated cylinder? A graduated cylinder because graduated cylinders have more precise increments of measurement along the sides in order to determine the volume of the liquid as beakers have larger increments. These smaller increments allow for greater ac cuaracy .

Chemistry 9-11 LAB Good

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