Gran plot
![Click on the image to view in full size. Figure 1. Sample Gran plots using data from Butler (1998). Note that the filled circles indicate the data points included in the least-squares computations to give the fitted dashed lines.](/Images/godic/202501/16/Sample_Gran_Plot4414.gif")
![Click on the image to view in full size. Figure 2. Sample Gran plots using data from](/Images/godic/202501/16/Sample_Gran_Plot_24414.gif")
![Click on the image to view in full size. Figure 3. Sample Gran plots using data from a titration of Cl− by Ag+ monitored potentiometrically. The potentials were converted to [Ag+] values for plotting. Note that the filled circles indicate the data points included in the least-squares computations to give the fitted dashed lines.](/Images/godic/202501/16/Sample_Gran_Plot_34414.gif")
A Gran plot (also known as Gran titration or the Gran method) is a common means of standardizing a titrate or titrant by estimating the equivalence volume or end point in a strong acid-strong base titration or in a potentiometric titration. Such plots have been also used to calibrate glass electrodes, to estimate the carbonate content of aqueous solutions, and to estimate the Ka values (acid dissociation constants) of weak acids and bases from titration data.