# Questions tagged [ph]

pH (or the potential of hydrogen) is a scale used to measure how acidic or basic an aqueous solution is.

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### Buffer Systems and Ion Reaction

If we have a buffer solution as follows where HA is a weak acid and $\ce{A-}$ is its conjugate base, $\ce{HA + H2O<=>H3O+ + A-}$, do we ever consider $\ce{A- + H2O<=>HA + OH-}$? This is ...
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### MgCl2 acidic or neutral in water?

I'm currently taking chemistry 12. On our test we were asked, when given a $0.1~\mathrm{M}$ solution of certain compounds whether the resulting solution when added to water would be acidic, basic, or ...
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### link between acidity and [H3O+]

Suppose I have an aqueous solution (1) of $\ce{CH3COOH}$. The chemical species in the solution will be $\ce{H2O, H3O+, CH3COO-}$ and, since it's a weak acid, some $\ce{CH3COOH}$ will remain. Suppose ...
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### How to calculate the amount of citric acid to neutralise the pH within wastewater?

We have an effluent tank, with a consent to discharge at between 5.5 - 11 pH, the tank holds 100000 liters of dirty water. When the pH reaches 10.5 we add citric acid to bring the pH down. How ...
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### Predictions about hydrolysis reactions [duplicate]

Predict whether these $1.0~\mathrm{M}$ solutions are acidic, basic, or neutral. Lets start with $\ce{CH3NH3+NO3-}$ How do I approach a problem such as this? I certainly do not know all the chemical ...
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### pH of bleach solution slowly decreasing?

I work within a science department in a school. We are demonstrating Universal Indicator and something odd has happened. Our bleach solution (~2.5% Sodium hypochlorite) turns blue when UI is added but ...
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### Why does p mean −log(x)?

$\mathrm{pH} = -\log[\ce{H+}]$ while $\mathrm{pOH} = -\log[\ce{OH-}]$ Why does $\mathrm p$ represent $-\log$ of something? Is it due to some historical reason or due to some scientific reason?
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### p-value for ions in a solution?

The question in my class notes read as: Calculate the p-value for each ion in a solution that is $2.00 \times 10^{-7}\ \mathrm{M}$ in $\ce{NaCl}$ and $5.4 \times 10^{-4}\ \mathrm{M}$ in $\ce{HCl}$....
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### Is there any law for pH conservation in chemical reactions?

I would like to know (just curiosity) if there is any law for pH conservation in chemical reactions. (like conservation of momentum in dynamics). EDIT The reaction I would like to take as example is ...
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### Does dissolving salt in water change the pH?

I am particularly interested in the effect or lack of effect of dissolved NaCl in regards to pH in water. It would be interesting also if anyone has any insight for other salts and their effects. ...
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### Why is the pKa of the thiol group in N-acetylcysteine higher then the pKa of the thiol group in cysteine?

I understand why cysteine has a $\mathrm pK_{\mathrm a}$ of 8.3. But the $\mathrm pK_{\mathrm a}$ of thiol in N-acetylcysteine is 9.27. Since there is an acetyl group attached to the nitrogen, doesn't ...
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### Solution for storing a glass electrode

What kind of storage solution is required for a glass electrode? Is 3 M $\ce{KCl}$ sufficient for this purpose? If so, what is the approximate pH of that solution (the solution I use presently has a ...
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### pH of sodium metasilicate anhydrous vs pentahydrate when dissolved in water

I'm not a chemist and don't remember much chemistry from school, so please forgive a naive question (I've read the Wikipedia article on sodium silicate though). I'm researching this topic to make ...
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### Amending soil pH to change the color of hydrangea flowers

I would like to ensure that my hydrangeas are blue. I am told that adding ammonium sulfate or aluminium sulfate will cause the soil to be more acidic. I am also told that adding elemental sulfur will ...
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### Ph of acid would be one? [closed]

I am interested in the chemical lsd or "acid". I wanted to know if lsd is acid in its pure form would that mean it is water?
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### About pH of an aqueous solution of SO2

Probably we can have an aqueous solution of $\ce{SO2}$ by dissolving it in water, because we would have an equilibrium between $\ce{SO2(g)}$ and $\ce{SO2(aq)}$: $$\ce{SO2(g) <=> SO2(aq)}$$ How ...
Is it possible to make a solution of ph 7 phosphate buffer solution using phosphoric acid and $\ce{K2HPO4}$ ? How can I calculate the amount of $\ce{K2HPO4}$ needed for 1L of phosphoric acid ? Edit: ...
The amino acids are Zwitterions. In neutral pH, an Amino acid's amino group has a postive charge and Carboxyl group has negative charge. They cancel each others charge thanks to the $Hydrogen$ that's ...