# Tag Info

### What is the pH of ice?

According to Martin Chaplin's Water Dissociation and pH: In ice, where the local hydrogen bonding rarely breaks to separate the constantly forming and re-associating ions, the dissociation constant ...
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### Sugar solutions have a neutral pH in themselves, but it makes your body acidic. Why?

It is not proven that "sugar makes your body acidic"! Your body's pH is very tightly regulated by the body's internal systems; it is also different in different parts of the body - the stomach is ...
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### Why are some pH standard solutions 6.86 and 9.18?

The pH 6.86 and 9.18 values come from NIST standard buffer solutions for pH calibration, as described in, for example, NBS special publication 260-53 (1988) (pdf available here). It appears they chose ...
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### How do I calculate the isoelectric point of amino acids, each of which has more than two values of pKa?

Since the $\mathrm{pI}$ is the $\mathrm{pH}$ at which the amino acid has no overall net charge, you need to average the $\mathrm pK_\mathrm a$ values relevant to the protonation/deprotonation of the ...
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### How can benzaldehyde have a pKa of 14.9?

Significant amount of geminal diol of benzaldehyde exists in an aqueous solution of benzaldehyde at 25 °C because $\mathrm{p}K_{\text{hyd}} = 2$ (Ref. 1) The $\mathrm{p}K_{\mathrm a}$ of benzyl ...
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### Calculation of the pH of a mixture of a strong acid and weak acid

Chemical thermodynamics is easy in that it always has enough equations to derive all the variables involved, and guarantees to produce a unique solution. The derivation itself may be not that easy, ...
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Some salts added obviously will alter the pH value of the soda ($\ce{NaHCO3}$, for example), and others not (like the example provided by you, $\ce{NaCl}$). Changing the ionic strength by addition of ...