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- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/11%3A_Spectroscopic_Methods/11.04%3A_Atomic_Absorption_SpectroscopyModern atomic absorption spectroscopy has its beginnings in 1955 as a result of the independent work of A. C. Walsh and C. T. J. Alkemade. Commercial instruments were in place by the early 1960s, and ...Modern atomic absorption spectroscopy has its beginnings in 1955 as a result of the independent work of A. C. Walsh and C. T. J. Alkemade. Commercial instruments were in place by the early 1960s, and the importance of atomic absorption as an analytical technique was soon evident. Atomic absorption spectrophotometers use the same optics described earlier for molecular absorption spectrophotometers, but with an important additional component—we must covert the analyte into free atoms.
- https://chem.libretexts.org/Courses/Lakehead_University/Analytical_I/8%3A_Titrimetric_Methods/8.2%3A_Acid%E2%80%93Base_TitrationsAcid–base titrations, in which an acidic or basic titrant reacts with a titrand that is a base or an acid, is probably the most common titration used by students in laboratories. To understand the rel...Acid–base titrations, in which an acidic or basic titrant reacts with a titrand that is a base or an acid, is probably the most common titration used by students in laboratories. To understand the relationship between an acid–base titration’s end point and its equivalence point we must know how the pH changes during a titration. We will learn how to calculate a titration curve using the equilibrium calculations from Chapter 6.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/14%3A_Developing_a_Standard_Method/14.07%3A_Chapter_Summary_and_Key_TermsThis chapter discusses the development of standard analytical methods in chemistry, focusing on optimizing experimental conditions, verifying precision and accuracy, and ensuring methods are suitable ...This chapter discusses the development of standard analytical methods in chemistry, focusing on optimizing experimental conditions, verifying precision and accuracy, and ensuring methods are suitable for general use. It outlines approaches such as one-factor-at-a-time and simplex optimization to find optimal responses.
- https://chem.libretexts.org/Courses/Saint_Marys_College_Notre_Dame_IN/CHEM_122-02_(Under_Construction)/1%3A_Review_from_CHEM_121/1.02%3A_Uncertainty_in_MeasurementMeasurements may be accurate, meaning that the measured value is the same as the true value; they may be precise, meaning that multiple measurements give nearly identical values (i.e., reproducible re...Measurements may be accurate, meaning that the measured value is the same as the true value; they may be precise, meaning that multiple measurements give nearly identical values (i.e., reproducible results); they may be both accurate and precise; or they may be neither accurate nor precise. The goal of scientists is to obtain measured values that are both accurate and precise.
- https://chem.libretexts.org/Workbench/OpenStax_Chemistry_Remixed%3A_Clovis_Community_College/01%3A_Essential_Ideas_of_Chemistry/1.05%3A_Measurement_Uncertainty_Accuracy_and_PrecisionQuantities can be exact or measured. Measured quantities have an associated uncertainty that is represented by the number of significant figures in the measurement. The uncertainty of a calculated val...Quantities can be exact or measured. Measured quantities have an associated uncertainty that is represented by the number of significant figures in the measurement. The uncertainty of a calculated value depends on the uncertainties in the values used in the calculation and is reflected in how the value is rounded. Measured values can be accurate (close to the true value) and/or precise (showing little variation when measured repeatedly).
- https://chem.libretexts.org/Workbench/Pick_Your_Poison%3A_Introduction_to_Materials_Toxicology/05%3A_Measurement_Uncertainty_Accuracy_and_PrecisionQuantities can be exact or measured. Measured quantities have an associated uncertainty that is represented by the number of significant figures in the measurement. The uncertainty of a calculated val...Quantities can be exact or measured. Measured quantities have an associated uncertainty that is represented by the number of significant figures in the measurement. The uncertainty of a calculated value depends on the uncertainties in the values used in the calculation and is reflected in how the value is rounded. Measured values can be accurate (close to the true value) and/or precise (showing little variation when measured repeatedly).
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/13%3A_Introduction_to_Ultraviolet_Visible_Absorption_Spectrometry
- https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introductory_Chemistry_(CK-12)/03%3A_Measurements/3.14%3A_Measurement_UncertaintyThis page discusses how police identify criminals through witness descriptions, focusing on the inherent uncertainty in measurements like height due to the quality of tools and the skill of the measur...This page discusses how police identify criminals through witness descriptions, focusing on the inherent uncertainty in measurements like height due to the quality of tools and the skill of the measurer. It emphasizes that precise tools, such as rulers with detailed markings, can improve measurement accuracy and reduce uncertainty, highlighting their significance in effective assessments.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/04%3A_The_Vocabulary_of_Analytical_Chemistry/4.4%3A_Selecting_an_Analytical_MethodA method is the application of a technique to a specific analyte in a specific matrix. We can develop an analytical method for determining the concentration of lead in drinking water using any of the ...A method is the application of a technique to a specific analyte in a specific matrix. We can develop an analytical method for determining the concentration of lead in drinking water using any of the techniques mentioned in the previous section. The requirements of the analysis determine the best method and consideration is given the following criteria: accuracy, precision, sensitivity, selectivity, robustness, ruggedness, scale of operation, analysis time, availability of equipment, and cost.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/15%3A_Developing_a_Standard_Method/15.2%3A_Verifying_the_MethodAfter developing and optimizing a method, the next step is to determine how well it works in the hands of a single analyst. Three steps make up this process: determining single-operator characteristic...After developing and optimizing a method, the next step is to determine how well it works in the hands of a single analyst. Three steps make up this process: determining single-operator characteristics, completing a blind analysis of standards, and determining the method’s ruggedness. If another standard method is available, then we can analyze the same sample using both methods and compare the results. If the result for any single test is unacceptable, then the method is not a suitable.
- https://chem.libretexts.org/Courses/Hope_College/CHEM_125/Exam_I/01%3A_Introduction_-_The_Ambit_of_Chemistry/1.03%3A_Handling_Large_and_Small_NumbersResults often involve very large numbers or very small fractions. Such numbers are inconvenient to write and hard to read correctly. One approach involves what is called scientific notation or exponen...Results often involve very large numbers or very small fractions. Such numbers are inconvenient to write and hard to read correctly. One approach involves what is called scientific notation or exponential notation.
