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

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Diluting acetic acid to obtain a solution of pH 5

What percent of a solution needs to be acetic acid for a particular $\mathrm{pH}$? I have 100% acetic acid, and want $1~\mathrm{L}$ of solution with a $\mathrm{pH}$ of 5. I've done some research, but ...
1
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2answers
62 views

Equilibrium constants for lewis acids such as Ca2+

I need to calculate the theoretical $\mathrm{pH}$ in a $50~\mathrm{mL}$ water solution where $6.4\times10^{-4}~\mathrm{g}$ of $\ce{Ca^{2+}}$ is present. The reaction I base this on is the following ...
-2
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0answers
17 views

Find the pH of the resulting solution [on hold]

What is the $\mathrm{pH}$ of the resulting solution when 40 ml of $\ce{HCl}$ reacts with 16 ml of $\ce{NaOH}$ ? ($\mathrm{pH}$ of $\ce{HCl}$ is 1 and $\mathrm{pH}$ of $\ce{NaOH}$ is 14)
2
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1answer
56 views

Finding pH of a buffer

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M methylamine, $\ce{CH3NH2}$, with 25.00 mL of 0.10 M methylammonium chloride, $\ce{CH3NH3Cl}$? Assume that the volume of the solutions ...
4
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3answers
53 views

Determining the H⁺ Concentration of Na₃PO₄

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 ...
1
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1answer
28 views

After mixing, which species has the dominant affect on the pH of the solution that remains?

A solution is created by mixing 250 mL of 1 M $\ce{HCl}$, 250 mL of 1 M $\ce{CH3COOH}$ and 500 mL of 1.5 M $\ce{CsOH}$. The $K_\text{a}(\ce{CH3COOH}) = 1.8 \times 10^{-5}$ What is the pH of this ...
3
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1answer
53 views

What is the pH of CsBr?

a) 3.8 b) 7 c) 9 d) 12 My Attempt: $\ce{Cs+ + H2O <<=> CsOH + H+}$ (because $\ce{CsOH}$ is a strong base, the forward reaction should not occur right)? $\ce{Br- + H2O <<=> HBr + ...
-3
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0answers
42 views

What is the volume of the KOH solution needed to reach the equivalence point of the titration and the ph at the equivalence point? [closed]

Consider titration of 35.00 mL of 0.05952 M nitrous acid, HNO2, with a standard 0.07925 M solution of potassium hydroxide, KOH. What is the volume of the KOH solution needed to reach the equivalence ...
2
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0answers
19 views

Alkaline glycine buffer molarity

Having never prepared a buffer solution before, I am hoping for a little help in understanding the process. This method I plan to use calls for a 0.1M glycine buffer at pH 10.6. Some internet ...
0
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1answer
46 views

Effect of dilution on pH for HCl

Is it necessary to consider common ion effect when suppose a strong acid like HCl is added to water? For example in this question: 10 mL of $10^{-6 } \ce{mol/L \ HCl}$ solution is mixed with 90 mL of ...
0
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1answer
30 views

Can I make a pH 7 buffer from phosphoric acid and sodium hydroxide?

I am an electronics guy with not so much knowledge of chemistry. I would like to prepare a pH 7 buffer to test pH meters. All web references I have found so far describing how to make a phosphate ...
3
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1answer
67 views

Calculating pH for titration of weak base with strong acid

Calculate the pH at the equivalence point for the titration of 0.130 M methylamine ($\ce{CH3NH2}$) with 0.130 M $\ce{HCl}$. The Kb of methylamine is ${5.0×10^{–4}}$. So I started with the equation: ...
0
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0answers
54 views

Preparing a buffer from benzoic acid and sodium benzoate [on hold]

The question is: "You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.180 M sodium benzoate. How much of each solution should be mixed to prepare ...
3
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0answers
25 views

How is the pKa of extremely weak acids determined?

According to Wikipedia the conjugate acid of LDA has a pKa of about 35 - which is in line with figures I've seen elsewhere. How then can such a weak acid's pKa of be determined? If the determination ...
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1answer
40 views

What's a good resource/book on pH measurements?

Most resources on pH and the electrochemistry behind it that I've found are IMHO too superficial. For example, they explain that an electrode with less than 80% slope should be discarded, but not why ...
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2answers
31 views

Can I use my extech pH 60 meter to measure soil pH if so how?

Can I use my extech pH60 meter to measure soil pH if so how? I included a link to the meter. Extech pH 60
3
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3answers
849 views

How concentrated can an acid be?

How concentrated can an acid be without it being supersaturated? Is there a certain limit to how concentrated an acid or base can be? When I mean concentration, I mean molarity; so how concentrated ...
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1answer
90 views

Chalcogens' hydrides as acids?

I've noticed that chalcogens never form binary acids, and instead end up like water, with very little acidity. Why is this? Or am I wrong and there's a counterexample, if so please give it.
3
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0answers
27 views

Slow acidification process

I'm trying to find a substitute of Glucono delta-lactone (GDL). This food additive is usually used to produce silk tofu. Because of its slow hydrolysis the pH decreases very smoothly, which results in ...
0
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1answer
65 views

Finding new pH after NaOH added to buffer soln given original pH and concentrations of both components

I have a buffer containing 0.2000 M of the acid HA, and 0.1500 M of it's conjugate base A-, with a pH of 3.35. I need to find the pH after 0.0015 mol of NaOH is added to 0.5000 L of the solution. I ...
0
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1answer
65 views

How do you find the pH of a solution from a density and weight percentage?

An $\ce{HCl}$ solution of density $\mathrm{1.19~g~ml^{-1}}$ has weight percentage of 38%. Find it's pH. Since there is no given volume I assume there is no way to solve this?
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1answer
38 views

How to calculate the pH of a sodium fluoride and hydrogen fluoride aqueous mixture? [closed]

What is the pH of a solution that is $0.20~\mathrm{M}$ in $\ce{HF}$ and $0.40~\mathrm{M}$ in $\ce{NaF}$? $K_a = 7.2\cdot10^{-4}$ I am stumped on this question. Is the concentration greater in ...
3
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1answer
30 views

Impossible pH For Aqueous Weak Acid Solution

An aqueous solution of $\ce{HCl}$ has a $\mathrm{pH}$ of $0.00$ if $[\ce{H+}] = 1.00 \; \mathrm{M}$. I tried to see if an aqueous solution of acetic acid could have a $\mathrm{pH}$ of $0.00$, given ...
3
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1answer
49 views

Carbonic acid-hydrogencarbonate buffer system pH calculation?

I am learning about the pH of buffer solutions, and am slightly confused by my text book's calculation. For the blood's buffer system of carbonic acid and hydrogencarbonate ions as the conjugate case, ...
4
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1answer
53 views

Why is ionic strength (mu) calculated differently for these 2 examples?

In the following examples; I don't understand why $\ce{Na_3PO_4}$ is a much more complicated process when calculating $\mu$ compared to $\ce{NaH_2PO_4}$ and $\ce{Na_2HPO_4}$. Specifically, I don't ...
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1answer
46 views

Henderson Hasselbach Equation

So will the hasselbach equation be able to calculate the pH when you have an acidic solution and you add a basic solution? Will that be possible or should you must add only add an acid to calculate ...
3
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2answers
42 views

How to report pH values?

I have measured the pH in the water-soluble fraction of a powder. I weighed in a certain amount of powder and a certain amount of water, and extracted the water-soluble fraction. I then measured the ...
3
votes
1answer
91 views

How do I know that an acid and conjugate base are present in equimolar amounts?

Acetylsalicylic acid is a molecule in several popular drugs such as Magnyl and aspirin. Its pKa is 3.5, and I'm about to calculate the pH of a 0.010 M solution of acetylsalicylic acid. I've read up ...
3
votes
1answer
42 views

Calculating charge of amino acids (am I doing it right?)

Please consider this picture of a peptide chain: I've done some examining on the different amino acids and concluded that the chain is as follows: Lys-Leu-Gly-Ser-Citrullin (variant of arginine). ...
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2answers
67 views

Which pH indicator will give a dramatic color change with small changes in the amount of carbon dioxide dissolved in water?

I want to do a demonstration for students where they take a capped syringe and change the volume above a solution of seltzer water. The amount of carbon dioxide dissolved will vary, hopefully ...
3
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2answers
111 views

How can pKas differ across similar protons of the same atom?

For example, citric acid has three acidic protons, all of which are carboxylic acids. Despite being part of the same functional groups, they all have very different pKas. Why (and how?) is this?
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3answers
74 views

Can a negative pH exist? [duplicate]

I am programming a small model to simulate diffusion of $\ce{H+}$ ions in human tissue. It's quite a simplistic model based on a naive algorithm, and I'm mostly doing it to familiarize with the ...
3
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1answer
33 views

Carbonate + acid reactions - How to recognize these type of reactions?

So I've got $$\ce{CaCO_3 + HCl \rightarrow CO_2 + H_2 O + CaCl_2}$$ I'm wondering how I can recognize these types of reactions? I know that when I mix an acid and a base I get salt and water but in ...
3
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1answer
115 views

pH Curves for Titrations

Why does the pH rapidly increase near the equivalence point during--why does the slope of the graph of a pH curve sharply increase around this area?
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2answers
49 views

Why is it that weak bases usually contain a Nitrogen?

Why do weak bases usually contain a nitrogen, I know there are two electrons on top for a bond of H but why is it mostly nitrogen? I know there are other elemental bases too but why do I keep seeing ...
3
votes
2answers
566 views

What's the pH of Vinegar when it generally contains 5% Acetic acid?

Vinegar generally contains 5% Acetic acid. We would expect the pH of vinegar to be approximately: a. 0 b. 3 c. 7 d. 9 e. 12 I don't have the key for this question, so I ...
2
votes
1answer
70 views

What is the S2− in 0.10 M hydrogen sulfide?

I found this question in one of the problem sets and I decided to try it, I keep getting 9.1 × 10−8 as the answer and I thought this since this is a diprotic acid and I made two equations and I keep ...
0
votes
1answer
67 views

How to calculate the pH of a citric acid solution after adding magnesium oxide? [closed]

$4.03~\mathrm{g}$ ($0.100~\mathrm{mol}$) of magnesium oxide is added to $100~\mathrm{mL}$ of a saturated ($4.00~\mathrm{mol\cdot L^{–1}}$) solution of citric acid. Calculate the pH of the resulting ...
0
votes
1answer
63 views

What ratio of bicarb to vinegar do I need in order for the result to be ph neutral?

This question stems from the one I just asked over at cooking where my recipe tasted decidedly off because the pH was wrong. The recipe called for 16g bicarb of soda and 15g of vinegar (mine was 5% ...
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1answer
57 views

Find amount of Acid and Base required to make buffer

I am wondering if it is possible to know exact amount of acid and base that we can put in together to make a buffer. I want to make a 0.05M Extraction buffer using Disodium Hydrogen Phosphate and ...
2
votes
2answers
60 views

Are all strong acids the same strength?

Since the six strong acids dissociate completely into their ions, and the reaction goes to completion, does this mean that acids such as $\ce{HI}$ and $\ce{HCl}$ have the same acidic strength? I know ...
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1answer
119 views

I have 100mg of a proteinase K lyophilized powder and I need to make it to a working concentration of 25mg/mL

So I know that I need to add $4~mL$ of solution to this powder, which will give me a concentration of the enzyme at $25\frac{mg}{mL}$. What I do not understand is how to decide how much of each of ...
0
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2answers
87 views

Hydrogen peroxide from water

Is it possible that $\ce{2 OH-}$ from water could react to form $\ce{H2O2}$? I mean most autoionization forms $\ce{H3O+}$ and $\ce{OH-}$. However I think it is possible that $\ce{H-}$ and $\ce{OH+}$ ...
2
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1answer
35 views

Finding pH of tri-protic acid

I am studying for my final and I am given this problem: A solution of sodium phosphate is made from 10.5 g sodium phosphate in 150 mL of water. What is the pH of this solution Given: Ka1, Ka2. ...
2
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1answer
46 views

how protons(H+) react with matter and cause the solution to be acid?

For example if my hands were put in a HCl solution how does the protons in the solution which in high amounts will interfere/react with my hand(skin->proteins..) and cause it to burn...or how protons ...
3
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1answer
69 views

Explanation for behavior of acetic acid in aquaponic/hydroponic systems?

Because aquaponics is hydroponics with fish & bacteria, options for adjusting pH are limited. Primarily people use phosphoric acid, hydrochloric acid, and nitric acid (heavily diluted). A less ...
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1answer
49 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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votes
1answer
139 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 ...
6
votes
2answers
76 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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0answers
58 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, ...