In the figure each of the acid (blue), base (red) and NaCl (black) segments are approximately straight lines over the ranges of concentration considered. This observation needs to be treated with caution as it is based on only three data points for each segment, and as noted above, there is considerable uncertainty in the estimates of 𝑘 ! . Moreover, 1/𝑘 ! must have a strictly positive limit as the concentrations of H + , HO -or Cl -tend to 0. Nonetheless, these plots give some indication that the presence in high concentrations of H + , HO -or Cl -decreases 𝑘 ! (increases 1/𝑘 ! ) in a systematic way. Chloride concentration (M) pH 1/k1 vs pH and chloride concentration acid base NaCl