Stands for Potential of Hydrogen and is a measure of how acidic or base an aqueous substance is.

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How to calculate the pH of this buffer solution? [on hold]

You prepare a buffer solution adding $\mathrm{61.06 g}$ of Benzoic Acid, $\ce{HC7H5O2}$ ($\mathrm{K_a = 6.4 x 10^{-5}}$ ), and 72.06 of Sodium benzoate, $\ce{NaC7H5O2}$ in $\mathrm{100 mL}$ of water. ...
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24 views

How to calculate the volume of this solution? [on hold]

Calculate the volume of the solution of Potassium hydroxide $\mathrm{0.1000 M}$ that is necesary to add to $\mathrm{15.00 mL}$ of a solution $\mathrm{0.2000 M}$ of Acetic acid to prepare a buffer ...
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1answer
47 views

Adding water on CH₃COONa. What's the new pH?

We have $10 \,\mathrm{L}$ of solution of $\ce{CH_3COONa}$ with concentration $C=1\,\mathrm{M}$ and $\mathrm{pH}=10$. Then we ad $90\,\mathrm{L} \space \ce{H_2O}$. The question is what will be the pH ...
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1answer
30 views

What does 0.12N mean on a bottle of sulfuric acid?

I just bought a bottle of sulfuric acid in order to simulate acid rain for an experiment. I was wondering what 0.12N on the bottle means. I need a simplified version of the explanation as I'm ...
1
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18 views

Dissociation of water into H+ and OH-: Does the law of mass action hold at nanoscale?

Suppose water under neutral conditions is confined in a virtual spherical nanocontainer with a radius of 25 nm. To calculate the number of hydronium ions, one uses water dissociation constant which is ...
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51 views

What is the pOH of a 0.0100 F solution of dipotassium phtalate?

What is the pOH of a 0.0100 F solution of dipotassium phtalate? pKa1 = 2.950 and pKa2 = 5.408 for phtalic acid. I did it for phthalic acid by calculating pH and then just doing pOH = 14.00 - pH, ...
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1answer
31 views

Finding the Ka of a weak acid after addition of a strong base

When 50.00 mL of an unknown 0.2461 M weak acid are titrated with 0.1968 M NaOH, it was found after the addition of exactly 16.00 mL of base that the pH of the solution was 3.79. From this information, ...
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51 views

Is there a pH range for “neutral” detergents?

There exist many home made pH scales like these But do any of you know if there is an "official" scale that defines if a neutral detergent is 7 sharp or within a range _______?
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1answer
59 views

Net charge of Peptides at pH1 and pH0

Taking Glycine and aspartic acid. As both the amino acids are fully protonated at pH 0 ad pH 1, how does the peptide bond form? Is it a two step mechanism where the OH from an alpha carboxyl group ...
1
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23 views

How can the pH value be unitless? [duplicate]

How can the definition of the pH value $pH=-log(H^+)$ yield a unitless result? Since $H^+$ is a concentration, wouldn't it have units $\frac{mol}{dm^3}$ and therefore following the product rule you ...
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1answer
73 views

How to calculate the pH of a phosphate buffer solution? [on hold]

Consider a buffer solution made from mixing $1~\mathrm{mL}$ of $\ce{Na2HPO4}$, $0.1~\mathrm{M}$, and $9~\mathrm{mL}$ of $\ce{NaH2PO4}$, $0.1~\mathrm{M}$ having $\mathrm{p}K_a = 7.21$. When ...
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1answer
24 views

pH Indicators for Hoffman apparatus

I've read that bromothymol blue can be mixed in with the electrolyte in the demonstration of electrolysis using a Hoffman apparatus. The indicator clearly shows the local differences in pH for the ...
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48 views

Ultraviolet acid base indicator

Is there a chemical(s) that provides good discrimination between absorbance curves for different pHs in the UV light spectrum (100-400nm?)
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2answers
53 views

Titration and calculation of the number of moles after a mix

I have the following problem on an assignment that I don't understand. Given the following balanced equation for the titration of HCl with NaOH: $\ce{HCl + NaOH -> NaCl + H2O}$ The initial ...
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1answer
23 views

Is the volume of a protein substrate equal before and after an enzymatic reaction? (pepsin degrading egg white suspension)

I am trying to determine the reaction rate of pepsin at different pH values by performing an experiment. I am using egg-white suspension as the substrate and am adding differently concentrated ...
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3k views

Which is the strongest acid?

According to Wikipedia $\ce{HeH+}$ and Fluoroantimonic Acid are the strongest. According to Nature, Carborane acid is the strongest, but Wikipedia says fluoroantimonic acid is stronger... Links: ...
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1answer
65 views

How could the pH of this solution rise instead of fall when exposed to the atmosphere?

I have a couple of big barrels with a 50L demi-water solution of the following nutrients: $$ \begin{array}{rl} 200~\mathrm{\mu M} & \ce{NH4NO3} & +\\ 30~\mathrm{\mu M} & \ce{KCl} & ...
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1answer
29 views

pH of baking soda in water? [closed]

If I dissolve 1g of sodium bicarbonate powder into 400 ml of distilled water, what will the pH of the resulting solution be?
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2answers
35 views

How to verify the accuracy of a pH meter

One suggestion I received is that I prepare a solution of a known activity and probe the solution with the pH meter. The problem I see with this is that any error in solution preparation can lead us ...
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1answer
22 views

pH Changes in primary cells

Primary Cells - pH changes during discharge Alkaline Cell: Manganese Dioxide Zinc Alkaline Cell Anode (-) $\ce {Zn(s) + 2OH^{−}(aq) → ZnO(s) + H2O(l) + ...
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1answer
52 views

What happens when 0.02 mole NaOH is added to a buffer solution?

I am asking this question for my son. (This question is related but we still have our confusions.) We have one liter buffer solution of 4.74 pH which contains 0.1 mole $\ce{CH_3COOH}$ and 0.1 mole ...
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1answer
160 views

Adjusting PBS with HCl: pH drift after dilution of phosphate buffer

It is some kind of everyday lab science and with a feel of shame I cannot answer this observation. I noticed a pH drift (~0.5 units) of my 10X phosphate buffer (PBS), when I adjust the pH with ...
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1answer
99 views

What is the pH of a solution of HCOONa and HNO3?

Calculate the pH of an aqueous solution obtained by mixing 20 ml of $\ce{HCOONa}$ 0, 1 M and 5 ml of $\ce{HNO_3}$ 0,2 M. ($K_a$ of $\ce{HCOOH}$ $= 10^{–4}$) My try: The number of the moles involved ...
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2answers
74 views

Is it true that a pH higher than the pKa of an acid make the H automatically disassociate?

Will the hydrogen atom always disassociate if the pH of the solution is higher than the pKa of the acid?
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2answers
81 views

Using non-food grade NaOH for pH control

I would like to use non-food grade $\ce{NaOH}$ for $\ce{pH}$ water treatment. Any problem with this mixing with water that contains iron? The $\ce{NaOH}$ will be pumped into a well. As a $25\%$ ...
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1answer
56 views

Concentration of hypochlorous acid and hypochlorite

Given a total chlorine concentration and the pH and pKa of $\ce{HOCl}$, how would you find the concentration of $\ce{OCl-}$ and $\ce{HOCl}$ disinfectants? If the given total chlorine concentration is ...
2
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2answers
435 views

Calculating pH of diprotic and amphoteric solutions

I am trying to understand this problem and its corresponding solution (complete solution not shown) First off, from the above one can see that the equilibrium constants when $\ce{H2ASO4-}$ ...
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2answers
679 views

How much can the pH change through dilution?

Consider an acidic solution with Hydrogen ion concentration, $\ce{[H+]}$ of $10^{-5}\:\mathrm{M}$. Since $\:\mathrm{pH} = -\log \ce{[H+]}$ the $\:\mathrm{pH}$ of solution is $5$. Suppose we dilute ...
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32 views

Deviation from ideal solutions - activities and concentrations

What are some examples of solutions deviating significantly from ideal behavior, and, by extension, showing pHs significantly different from those predicted by usage of concentrations instead of ...
5
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1answer
88 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 ...
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1answer
47 views

Figuring out the pH

So, I'm refreshing my college chemistry a bit. Could someone give me a pointer on the following practice exercise? What is the pH @ 25 degrees Celcius in a bucket with 10liter pure water in which a ...
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1answer
32 views

Activities of Solutes - especially acids and bases

What is the concentration of hydrochloric acid needed to have a solution with the activity of the hydrogen proton = 1? I read 1.18 M somewhere but I am unable to find a corroborating source. Also, how ...
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1answer
88 views

How to calculate the pH of a buffered solution with Henderson Hasselbalch?

Lets say you have a buffered solution containing $0.50~\mathrm{M}$ acetic acid ($K_a = 1.8 \cdot 10^{-5}$) and $0.50~\mathrm{M}$ sodium acetate, and you want to calculate the $\mathrm{p}\ce{H}$ of ...
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2answers
89 views

How can water with a very low hardness have substantial buffer capacity?

My freshwater fish tank has a pH of 5.8 and a KH value in excess of 40 or 720+ppm while still maintaining a water hardness of 20 ppm or GH< 1 now I am a math/phsyics student but I have taken both ...
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248 views

Protonation of Guanidine

Why is the $\ce{sp^2}$ hybridized nitrogen atom in guanidine the most basic? I know that as a general guideline, $\ce{sp^3}$ hybridized atoms are more basic than $\ce{sp^2}$. Bases are electron ...
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217 views

Calculating the pH of a dilluted aqueous KOH solution

I am not a chemist at all, but I wanted to help someone to get to the solution for the task of calculating the $\mathrm{p}\ce{H}$ of an aqueous solution of $0.01\:\mathrm{nM}~\ce{KOH}$ in water. ...
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1answer
159 views

No indicator is suitable when titrating weak acid with weak alkali

This was a statement in my book: A solution of a weak acid cannot be titrated with a weak base using an indicator to find the end-point because the pH change is too gradual close to the equivalence ...
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Galvanic Element: Silver Iodide and Standard Hydrogen cell

I have to calculate the $\mathrm{p}\ce{H}$ of the $\ce{H+}$ solution with the following info: $\ce{Ag(s) | AgI(s) || H2(g)(1atm) | H+(aq) (X mol/L) | Pt(s)}$ $E=0.1\:\mathrm{V}$ Temperature ...
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Why does pH affect fermentation?

I know that the lower the pH the faster fermentation occurs. Why does this happen?
3
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1answer
97 views

Accuracy of pH meters in MgSO4 solution

I bought a 2 pH meters several months back from Amazon for roughly $10 a piece. I couldn't tell you how they work, but here's the link on Amazon: ...
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173 views

Why does depurination happen at a higher pH (or under less harsh conditions) than depyrimidation?

I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ...
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1answer
108 views

pH of a solution of acetic acid and ammonium acetate

After studying ionic equilibrium, I was just making some wild questions and I was unable to calculate the $\ce{pH}$ of this solution. Assume, 1 mole of each was added to $1L$ solution of water. My ...
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2answers
74 views

How to tell the pH of HC2H3O2?

The Question I am trying to Solve: The pH of a 0.500 M solution of $\ce{KC2H3O2}$. My First Question: How would I go about calculating this? My Second Question: Is the $\ce{H3O}$ in the middle of ...
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1answer
169 views

is water a non-metallic oxide? and hence acidic in nature?

I just read about non-metallic oxides in my textbook which says that non-metallic oxides are a compound formed of an oxide ion and a non-metal. It also said that they are acidic in nature. It gave ...
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62 views

What are the factors that affect the corrosiveness of an acid?

Acids are usually corrosive but what determines this? Is it the concentration of the acid or strength of the acid ($K_a$ value)?
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1answer
65 views

Thymolphthalein solubility

I already know that thymolphthalein is soluble in alcohols, very alkaline aqueous solutions, acetone, and propylene glycol methyl ether. My questions are what other solvents dissolve thymolphthalein, ...
2
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1answer
106 views

Amphoteric amino acid titration

Glycine $(\ce{NH2CH2COOH})$ is an amino acid with two $\mathrm{p}K_a$ values $(\mathrm{p}K_{a,1}=2.0, \ \ce{COOH};\ \mathrm{p}K_{a,2}=10.0, \ \ce{NH2})$. (a) If $0.01~\mathrm{mol}$ of this amino ...
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2answers
626 views

Determine the pH of mixture of two weak acids

We've two solutions : Solution 1 $HCOOH$ its concentration is $c_1=10^{-2} mol/l$ and its volume is $v_1 = 50 ml$ and its $pH_1 = 2.9$ Solution 2 $CH_3COOH$ its concentration is $c_2=10^{-2} mol/l$ ...
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1answer
88 views

Predicting the pH of a weak acid and weak base solution

I know that it is possible to predict whether combinations of acids and bases will be acidic, basic, or neutral: weak acid (WA) and strong base (SB) reacts basic strong acid (SA) and and weak base ...
2
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How much hydrolysis will likely occur of the following bonds at pH 1-4 in the time period of 1-3 hours?

The bonds are: (I have given pictures of what I mean in case there's any ambiguity that I leave open in these questions. Also so that if you want to number the R groups you've got a head-start) ...