New answers tagged ph
5
To quote the key points of an easy to read publication by Salgado and Vargas-Hernández (doi 10.4236/ajac.2014.517135, open access):
All starts with the dissociation equilibrium between the acid $\ce{HA}$ and its anion $\ce{A-}$ for which you write
$$\ce{HA + H2O <=> H3O+ + A-}$$
By consequence of this, the recorded total absorbance $A_\mathrm{t}$ ...
3
As pointed out in the comments, the concept of pH as a thermodynamic property of nanodroplets does not quite make sense unless the nanodroplets are in equilibrium (stable). If they are in equilibrium you can still apply the equation
$$\textrm{pH}=-\log_{10}(a_{\ce{H+}})$$ but now you have to be aware that the activity will be influenced by surface (and ...
-1
If you add NaCl to any neutral or acidic solution, the pH will decrease by a factor of at least 0.5. This is due to the fact that the pH is not the log of the concentration calculated with respect to the total volume, but the concentration should be calculated with respect to the volume of free water. In concentrated NaCl solutions, nearly all water ...
2
Please be aware that adding salt changes the ionic strength of your solution. Therefore, the activity $a_\mathrm H$ of $\ce{H+}$ is changed. This changes $\mathrm{pH}=-\log_{10}(a_\mathrm H)$. In a 1 molar $\ce{NaCl}$ solution ($I\approx 1\ \mathrm{mol/l}$) the Debye-Hueckel (DH) approximation gives a shift of the activity by around 0.5 pH units (compared to ...
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