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30 Αυγ 2024 · To calculate the standard deviation for the analyte’s concentration we must determine the values for \ (\overline {S}_ {std}\) and for \ (\sum_ {i = 1}^ {2} (C_ {std_i} - \overline {C}_ {std})^2\). The former is just the average signal for the calibration standards, which, using the data in Table 2.5.1 , is 30.385.
The standard deviation, \(\sigma\), describes the spread of a data set’s individual values about its mean, and is given as \[ \sigma=\sqrt{\frac{\sum_{i}^{ }(X_i-\overline{X})^2}{n-1}} \tag{4.1}\] where X i is one of n individual values in the data set, and X is the data set’s mean (average) value.
The goal of scientists is to obtain measured values that are both accurate and precise. Suppose, for example, that the mass of a sample of gold was measured on one balance and found to be 1.896 g. On a different balance, the same sample was found to have a mass of 1.125 g.
Here are the most common ways to calculate experimental error: Error Formula. In general, error is the difference between an accepted or theoretical value and an experimental value. Error = Experimental Value - Known Value. Relative Error Formula. Relative Error = Error / Known Value. Percent Error Formula. % Error = Relative Error x 100%
Learn about and revise calculations in chemistry with this BBC Bitesize GCSE Chemistry (AQA) study guide.
Valid measurements. In general, scientists work out explanations based on repeatedly collecting and analysing data. The way in which scientists develop explanations is known as the scientific...
