# 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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### How identify acid and base for Henderson-Hasselbach equation [closed]

If I am asked to determine the pH in e.g. 60 mM Na2CO3 and 30 mM NaHCO3 or 50 mM NaHSO4 and 40 mM Na2SO4 How do I go about to identify which of these two is the base and which is the acid? ...
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### Why is the pH level of carbonation loss decreasing then increases afterwards?

We have done an experiment of the titration of unsealed sprite soda to find the amount of carbonic acid being loss on various duration (0 to 1 hour), due to decrease pressure. The calculation was to ...
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### Finding the molarity of an unknown weak acid when its pH and volume is given

In lab we measured the pH of $\pu{25.0 mL}$ of an unknown acid. The pH was $2.43$. I’m supposed to figure out the molarity. How? I don’t know the $K_a$ or anything. Volume seems useless. I really just ...
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### How was the ionization constant of water found? [closed]

We were just starting to learn about pH in school recently and we learned that $K_w$ is a constant at $\pu{298 K}$ and it's equal to $10^{-14}$, the teacher said this could be found experimentally but ...
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### How to calculate the amount of solid soda added to increase the pH of a solution [closed]

0.1 mole of HCN and 0.01 mole of AgI are in solution in 1 litre of water. We add solid soda to increase the pH of the solution. Ka(HCN/CN-)=10^-9.2 Ks(AgI)=10^-16 KD(Age(CN)^- 2)=10^-21 When the AgI ...
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### Dilution of Ca(OH)2 and its pH [closed]

A basic solution of Ca(OH)2 was diluted until a final concentration of 10^-9 M. What is the pH?
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### Is menthol in aqueous solution acidic or alkaline? [closed]

I was wondering whether the menthol added in common "mint based" chewing gum has a potentially acidic nature. I can't seem to find any answers for this via a web search.
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### Why does pH affect fermentation?

I know that the lower the pH the faster fermentation occurs. Why does this happen?
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### Is there a relationship between acidity of the water solution and oxidation/reduction reactions?

What I want to know is if there is a relationship between the acidity of the water solution and redox reactions and if there is a relationship what favors the oxidation and what favors the reduction? ...
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### Acidity comparison on R-PO3H2

Question Compare the acidity $(K_\mathrm{a1})$ of the following three acids: $\ce{H3PO4},$ $\ce{Ph-PO(OH)2}$ and $\ce{H3C-PO(OH)2}.$ Thoughts These three acids are of type $\ce{R-PO3H2},$ where ...
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### Fitting multiple pKa's

I have three histidine residues that are next to each other in a protein. When I compute the fraction of unprotonated states for each individual histidine as a function of $\mathrm{pH}$ my titration ...
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### Use of Concentration for pH

When we find the pH of a solution, do we use normality or molarity? My teacher said that if the compound is present by itself, we can use normality but in all other cases we should use molarity. Can ...
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### How to clean pocket pH meter before storage?

Hello. I read about different methods how to clean this specific(attached photo)pocket pH meter before storage and i can't figure out what is the right way. One method says to stir the pH meter(...
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### Relationship between pH and volume

I had prepared two different volume of solution: $\pu{500 mL}$ and $\pu{100 mL}$ with same concentration ($1\%$), but I obtain different $\mathrm{pH}$. Will volume affect $\mathrm{pH}$?
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### pKa of phenols using UV-Vis spectroscopy

I have done an experiment where I dissolved four different substituted phenols in acidic, basic, and buffer solutions, and recorded the UV-Vis spectra for each. I'm supposed to pick a wavelength where ...
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