CHE 106 Lecture Notes - Lecture 5: Significant Figures, Dimensional Analysis, Scientific Notation

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CHE 106 Lecture Notes - Lecture 4: Scanning Tunneling Microscope, Atomic Number, Nuclide

CHE 106 Lecture Notes - Lecture 5: Significant Figures, Dimensional Analysis, Scientific Notation

CHE 106 Lecture Notes - Lecture 6: Ernest Marsden, Ernest Rutherford, Hans Geiger

Document Summary

Precision: refers to the closeness of the set of values obtained from identical measurements of a quantity. Accuracy: refers to the closeness of a single measurement to its true value: precision is how close a value is to other observations, accuracy is how close a value is to the correct answer. Rules for calculating with significant figure: adding/subtracting, same number of decimal places as least amount used, multiplying/dividing, as many significant figures as least amount used. Scientific notation: expresses number as a product of a number and a power of ten.

Related Questions

Number Significant figures Explanation
23.56 4 All nonzero digits are significant.
500.01 5 Zeros between nonzero digits are significant.
23.560 5 Trailing zeros are significant when a decimal point isshown.
0.0078 2 Leading zeros are not significant.
1000 ? Trailing zeros at the end of a number but before a decimalare ambiguous.

Part A
Determine the number of significant figures in the measurement 6.07m ?
Express your answer numerically as an integer.

Part B
Determine the number of significant figures in the measurement0.0030 s ?
Express your answer numerically as an integer.

Part C
Round the value 44.981 g to three significant figures.
Express your answer numerically using three significant figures.

Experimental outcomes in chemistry depend on making sound observations, taking precise measurements and accurately recording them directly in to the laboratory notebook. All experiments and therefore the results will contain errors (experimental error), which can adversely affect the reliability of the experiment and the credibility of the scientist. Experimental error is reduced when students master experimental techniques and become aware of which measurements have the most impact on the experiment in terms of accuracy and precision. Accuracy is determined by comparing the true or actual value to an individual experimental value or the average of many experimental values. If the true value is not given, the average of all the experimental values is assumed to be true value and accuracy is determined by comparing the average to the individual experimental values. Precision is a determined by comparing how close all the experimental values are to each other. The following data was collected by students in your laboratory section. Decide which value to you will use to complete the experimental calculations. The amount of error in your final experimental result depends on your decision. Each student used a different balance and weighed the beaker 4 times. The balances they used in the laboratory read to a hundredth of a gram. The results are shown below were recorded by each individual. What additional information about the students, instruments, and the conditions which the data was collected do you need to better of the evaluate the reliability of the experimental data? Give 1 and briefly (60 words or less, using complete sentences) explain your answer. Which set of data is the most precise? Show all equations and calculations. Briefly (60 words or less, using complete sentences) explain your answer. What student measurements are the least accurate? Briefly (60 words or less, using complete sentences) suggest how this student could improve their experimental techniques. Show all equation and calculations

CHE 106 Lecture Notes - Lecture 5: Significant Figures, Dimensional Analysis, Scientific Notation

CHE 106 Lecture Notes - Lecture 4: Scanning Tunneling Microscope, Atomic Number, Nuclide

CHE 106 Lecture Notes - Lecture 5: Significant Figures, Dimensional Analysis, Scientific Notation

CHE 106 Lecture Notes - Lecture 6: Ernest Marsden, Ernest Rutherford, Hans Geiger

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