# 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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### Iterative method for calculating pH of a weak acid / base

The problem asks to determine the $[\ce{H+}]$ in a $0.20~\mathrm{M}$ solution of $\ce{Na3PO4}$. The $K_\mathrm{a}$ of $\ce{HPO4-}$ was given as $4.5\times 10^{-13}$, which then allows one to calculate ...
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### pH probe bulb - what is happening within the glass?

I am trying to understand how the glass bulb of a pH electrode of a pH meter works - the glass bulb itself. Not the reference electrode or the rest of the electrode (HCl, Ag/AgCl wire, etc...), the ...
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### How do you calculate pH, with different types of acids in solution? [on hold]

New question 41.0 mL of 0.0150 M hydrochloric acid, 130 mL of 0.0650 M hydroiodic acid and 55 mL of 0.00680 M sulfuric acid are pipetted into a 250 mL volumetric flask, which is then filled up to the ...
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### In the picture below, which one is acidic, alkalalinse and neutral [on hold]

Which form do you think is present at acidic pH, which one in neutral solutions, and which one in alkaline solutions? Briefly justify your answers, based on the availability of protons at different pH ...
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### How to calculate pH of final solution using volume and pH of initial solutions? [on hold]

When two solutions of equal volume with pH 2 and 8 are mixed, what happens to resulting pH ? How to calculate the final pH? I am being too specific this time.
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### How does pH affect the degradation of ascorbic acid (vitamin C)?

I know that vitamin C degrades over time (as I understand through oxidation). However, I am having trouble understanding how changing the pH of the solution in which the vitamin C is affects the rate ...
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### Calculating ionic strength and pH of a buffer solution [on hold]

Im trying to calculate ion strength and pH of solution. Components of the solution: 47 ul of 1000 pmol DNA in Elution Buffer (10 mM Tris-HCl pH 8.5) was bound to 3 ul of 10 µM YoYo1 (flourescent dye) ...
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### Calculate pH of final solution using volume and pH of initial solutions [closed]

I have an 800mL solution of TBS (pKa=8.06), HCl, and water at a pH of 7.61 to which I add 200mL of pure 7.0 pH water. What is my final pH? Please show me the calculation too.
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### The time-dependent pH value in a fermentation

I want to know if someone has supporting tips or solutions to my problem: In biotechnology, fermentations are used to grow microorganisms. These need a specific media/broth in which temperature, pH, ...
How to would we know if a salt such as $\ce{CO_2}$ reacts acidic or basic in water. The explanation I see everywhere is that you have to see the acid and base that makes up the salt, in the case of $\... 1answer 53 views ### How does sodium carbonate reduce pH? Sodium carbonate is used in pools to raise pH. From my understanding, it would dissociate in water like so: $$\ce{Na2CO3 <=> 2 Na+ + CO3^2-}$$ To raise pH, doesn't it have to absorb hydrogen ... 1answer 101 views ### pH of very dilute acids From doing some research on the site I have found that many people have posted about solutions of$\ce{HCl}$where$[\ce{HCl}] = \pu{1e-8 mol dm-3}$Here they are able to deduce $$[\ce{H+}] = \frac{[... 1answer 42 views ### Acid solution — lower pH when diluted Today I came across a "thought experiment" regarding \mathrm{pH} of a diluted acid solution. This idea looks somewhat logical but obviously contradicts the reality. Can you show me where is the ... 0answers 31 views ### Effects of gamma irradiation on pH buffer Does anybody know if it is possible to gamma-irradiate a bottle of pH buffer to sterilise it? Are there any known effects (short-term or long-term) of the irradition process on the pH qualities of the ... 0answers 44 views ### What is the pH of a solution of iron acetate? What is the pH of a \ce{0.1 M} solution of \ce{Fe(CH_3COO)_3}? I'm not sure how to do this, as it would involve complicated mass balance equations, but I think I can apply the approximation \ce{... 3answers 65 views ### Doubt on process to calculate pKa [closed] I have to solve an exercise that I've been trying for a long time without success. Information that I have: pH @ certain temperature of an aqueous dissolution of an acid molar concentration ... 1answer 53 views ### Confusion regarding calculating the pH of a salt of weak acid and weak base I need to calculate the \mathrm{pH} of a salt of weak acid and weak base in an aqueous solution. Method I used for calculation For a salt of weak acid and weak base (assuming complete dissociation ... 1answer 2k views ### Calculating the pH upon titrating barium hydroxide and hydrochloric acid Question: Calculate the pH produced from mixing \pu{25.0 mL} of \pu{0.420 M} \ce{Ba(OH)_2} with \pu{125 mL} of \pu{0.120 M} \ce{ HCl}. Attempt: I'm learning about acids and bases ... 1answer 64 views ### Titration of barium(II) hydroxide by hydrochloric acid \pu{25 ml} of \pu{0.024 M} \ce{HCl} is titrated into a volumetric flask which initially contains \pu{45 ml} of \pu{0.034 M} \ce{Ba(OH)2}. Calculate the \mathrm{pH}. This is how I ... 1answer 55 views ### 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 ... 0answers 18 views ### Why might litmus paper and universal indicator give conflicting pH readings in an acid-carbonate reaction? The resulting neutralised (which wasn't actually neutralised due to not realising CaCO3's insolubility) solution between Hydrochloric Acid and Calcium Carbonate, as per balanced equation CaCO₃ + 2HCl ... 1answer 30 views ### Acid/Base Indicator [closed] I'm not sure how the concept and math work on this problem. Can someone show me how you can get the answer, both conceptually and using math? 1answer 26 views ### Calculating the pH of Strong Acid Solutions [closed] Calculate the \mathrm{pH} of a \pu{1.5e–11 M} solution of \ce{HCl}. How is the \mathrm{pH}~7? 1answer 162 views ### 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 ... 1answer 211 views ### Why does slaked lime water lose alkalinity over time? When I throw 3 handfuls of white lime \ce{Ca(OH)_2} into 60 gallons of tap water, the initial pH value is 11.4, but unknowingly it changes to pH 7. What is the chemistry behind it? How long does ... 1answer 72 views ### Why does pH of a buffer solution change according to Henderson–Hasselbalch equation? [closed] If I add a little amount of acid or base to a buffer solution, the pH of the buffer won't change. That's what the diagramatic mechanism tells us. But according to Henderson–Hasselbalch equation, the ... 0answers 28 views ### Do TDS meters measure HCO₃⁻/CO₃²⁻? I am trying to add \pu{2 g} of \ce{KHCO3} to \pu{20 L} of RO water (\mathrm{pH} = 5.2) which theoretically it will add$$ \begin{array}{lr} \hline \ce{K+} &\pu{10.32 ppm} \\ \ce{HCO3-} &... 0answers 20 views ### What is the cause for the difference in pH between NaCl and Ringer Lactate Reading this article, I came across a passage which got me to think of this question: "Normal saline contains approximately$\pu{154mM}$of each$\ce{Na+}$and$\ce{Cl-}$with average pH of 5.0 and ... 0answers 28 views ### Acid and base separation on an anion exchange column [closed] I'm new with this concept and so I would need some advice. I want to separate an acid and a base in a water solution. The acid has$\mathrm{p}K_\mathrm{a}(\ce{HA}) = 5$and the corresponding acid of ... 1answer 4k views ### Is there a means to measure pH without indicators? I have created a solution that should contain hydroxide ions. Therefore, the pH > 7, but is there any way to roughly estimate the pH in absence of any indicator? Maybe using current, or checking ... 0answers 55 views ### Calculate the pH Calculate the pH of a dissolution of 100 ml of 0.1 M solution of ammonium chloride in the style of 100 ml of 0.1 M hydrochloric acid solution$\ce{NH4Cl -> NH4+ + Cl-}\ce{HCl -> H+ + Cl-}$... 2answers 818 views ### Why are synthetic pH indicators used over natural indicators? Synthetic indicators seem to be exclusively used when determining the pH of a substance with an indicator (with the exception of that school experiment where you boil cabbage to demonstrate natural pH ... 0answers 51 views ### How does a pH glass electrode work? Every source I read mentions the potential difference building up at the glass membrane (according to the Nernst equation). But how is this difference actually measured? Sticking an electrode into a ... 1answer 108 views ### Calculating pH when weak base is added to an strong acid$\ce{NH3}$solution of$\pu{0.1 mol dm-3}$is being added to a$\pu{25.0 cm3}$of$\pu{0.1 mol dm-3}\ce{HCl}$solution. Calculate the pH of the solution when volume of added$\ce{NH3}$solution is$...
In water, ethanol has a $\mathrm{p}K_\mathrm{a} = 15.9$ which means that its $\mathrm{p}K_\mathrm{b}$ is $-1.9$. Which implies that all weak acids in water are in fact strong bases. But this is not ...