# 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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### What effect does the weak base have here?

Suppose we reacted enough strong base to fully neutralise a weak acid, clearly at this point (the equivalence point) the $pH$ would not be $7$. This is because the reaction between the strong base and ...
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### Hydrolysis of $A_3B$ type weak acid-weak base salt

I know the formulae for weak acid-weak base salt of AB type. A peculiar question made me ask this. Do the formula for derived for AB type also hold for A3B type sal. For example: This is the question, ...
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### pH calculation of HCOOH +plus HCl solution

Question - What volume of $0.1 \ce{M}$ $\ce{HCl}$ solution should be added to a $\ce{500 mL}$ of $\ce{0.5 M }$ $\ce{HCOOH }$ solution in order to prepare an acid solution of $\text{pH}$ =$1.5.$ $K_a$...
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### Proper batch adsorption mechanism for heavy metals

I'm a college student with scope on environmental science, specifically the adsorption of heavy metals in aquatic media. Currently, I suffered from serious issue of batch adsorption mechanism, which ...
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### Change in pH/acidity of vinegar after adding aqueous NaCl

There's a question in my (grade 10) textbook asking to determine what will happen to the pH/acidity of vinegar if a solution of sodium chloride in distilled water is added to it drop by drop. The ...
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### Find the pH of a solution obtained by mixing 100 ml 0.1m Na3PO4 and 100 ml 0.1 M NaH2PO4. Given that H3PO4: [Κα₁ = 10^-4, Κα₂ = 10^-7, Каз = 10^-11] [closed]

So, my query is that since NaH2PO4 is a weak acid, and Na3PO4 is a basic salt, wouldn't they react? Another theory was that since NaH2PO4 is a weak acid and Na3PO4 is a salt of strong acid and NaH2PO4,...
1 vote
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### Aquatic chemistry, pH and alkalinity

Hope you can help me with an aquatic chemistry question. I have different types of water of different pH and alkalinity. pH, alkalinity, HCO3 and CO2 concentrations are known. I need to calculate the ...
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### How can benzaldehyde have a pKa of 14.9?

There are numerous websites out there which claim that the pKa of benzaldehyde – C6H5CHO – is 14.90. (Just do a Google search for benzaldehyde pka to see what I ...
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### Why can Neutral Red (indicator) not test values below its pKa?

It is the only indicator I have found that does not test below its pka, and can't think of any reason for this. Neutral Red has a pKa value of 6.8. ( Reference 1, Reference 2 ), but looking at its pH ...
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### Alternative pH sensing methods?

I am looking for alternative methods to measure the pH of water (swimming pools, tap water, rivers,...) with (ideally) the following properties: Durable: no maintenance or calibration required for 5-...
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### Does pH affect the activation energy of decomposition of hydrogen peroxide using iron (III) nitrate solution?

I know that pH can affect the activation energy of the decomposition of hydrogen peroxide when catalase is used, as catalase is an enzyme. However, if I use some nonenzymatic catalysts like iron (III) ...
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### How long can pH solution calibration be used for?

I am using a pH meter regularly (6 to 12 time per week), used mostly for home-food processing (mostly measuring the acidity of whey). The meter requires weekly calibration, which is quite time ...
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I grow things for a living and regularly use pH meters + strips to read and adjust the pH of various nutrient and pesticide solutions. Oftentimes, I have a need for nearly naked water with the pH ...
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### Finding the pH level of a liquid process

A photo of 15ml of distilled water accompanied with 3 drops of both universal indicator and bromothymol blue were mixed together and taken (white background was put into the back of the beake). The ...
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### Is LiOH a weaker base than NaOH?

Is $\ce{LiOH}$ a weaker base than $\ce{NaOH}$? Note: I'm not interested in "why," but rather what the "real" $\mathrm{p}K_ \mathrm{b}$ values are.  \begin{array}{lcc} \text{Data for Alkali Metal ...
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### Why my mineral water from different sources do not mixed well? [closed]

Background: In 8 hours range, I have bought cold mineral water (brand A), then refill the plastic bottle with cold mineral water (brand B) from my office. As far i know, brand B has high pH while ...
1 vote
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### The effect of pH and solubility on coagulation in water treatment

In water treatment, a specific pH range must be met in order for the process of coagulation to occur properly. Sources have stated this is due to the pH affecting the solubility of the coagulant, but ...
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### Calculate pH of imidazole in solution

I am having trouble understanding how to know how a molecule will reaction in solution. For example, if I have $\pu{1 M}$ of imidazole in solution, how can I calculate the pH of the solution by only ...