Question Video: Calculating the Average Titer Volume Chemistry

A titration experiment is performed 7 times. The first titration is used as a rough estimate of where the endpoint may be, whilst the remaining six titrations are used to try and provide an accurate measurement. What is the average titer volume? Give your answer to 2 decimal places.

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Video Transcript

A titration experiment is performed seven times. The first titration is used as a rough estimate of where the endpoint may be, whilst the remaining six titrations are used to try and provide an accurate measurement. What is the average titer volume? Give your answer to two decimal places.

The first titration was used as a rough estimate of where the endpoint may be and does not provide an accurate measurement of the amount of titer needed. We should therefore discount the value for titration one. We can plot the remaining volume data points on a number line to easily see where the distribution lies and to discount any anomalies.

An anomaly is a data point that differs significantly from other observations. These data points should not be included in our average. We can see that the majority of our data points fall between 18.9 centimeters cubed and 19.4 centimeters cubed, with the data points at 17.6 centimeters cubed and 20.6 centimeters cubed falling significantly outside of this cluster. We can therefore discount the values for titration number four and titration number seven as anomalies.

With a rough estimate and anomalies discounted, we can now calculate the average volume. We simply add together the volumes for titrations two, three, five, and six and divide by the number of data points used, four. Performing the calculation gives us an average titer volume of 19.15 centimeters cubed.