Questions tagged [buffer]
Use for questions regarding solutions containing a mixture of a strong acid and weak base or vice versa.
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Non-binding buffer at pKa of roughly 6 that dissolves in ethanol?
I'm trying to find a proper buffer for my experiment, which I'd appreciate some suggestions on. I have a solution in which I want to measure the concentration of magnesium ions using a fluorescent ...
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Calculating the pKA value of a mixture of two weak acids?
Will it be possible to find the pKa value of two weak acids? I am working on a project for school on calculating buffer capacities and to find the pH of the buffer solution, I have seen that you need ...
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Calculate the buffer capacity of a mixture/solution?
I am planning an experiment where I am measuring the buffer capacity of a mixture. However the mixture has two weak acids in it. Will having multiple weak acids in the mixture cause any changes in the ...
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Dihydrogenphosphate and hydrogenphosphate buffer solution
I have just come across a problem involving a buffer solution comprising of dihydrogenphosphate ions and hydrogen phosphate ions, which asks how the mixture of these two ions can function as a buffer ...
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Assessing stability of protein used for interaction experiments after changing buffer from tris to HEPES
I have a protein with a theoretical $\mathrm{pI}~9.0$ currently stored in $\pu{25 mM}$ tris and $\pu{250 mM}$ $\ce{NaCl}$ $(\mathrm{pH}~8)$ at $\pu{−80 °C}.$ I need to do experiments in HEPES at $\...
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Stability of n-Dodecyl-beta-D-maltoside in buffer solutions for assay experiments
I have a buffer system which contains multiple salts and in addition DTT and n-Dodecyl-beta-D-maltoside.
I understand that DTT is hydrolysing quite fast and this component must be used always fresh ...
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Why are buffer solutions not neutral
I am very confused about buffer solutions and I have lots of ideas about them which don’t integrate together so I really can’t tell which are correct and which are wrong. That being the case it’s ...
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answer
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Effects when 100 mmol NaHCO3 are mixed with 50 mmol HCl
I read somewhere that when $\pu{100 mmol}\ \ce{NaHCO3}$ are mixed with $\pu{50 mmol}\ \ce{HCl}$, a buffer arises. I'm confused, since $\ce{HCl}$ is a strong acid, and I thought the classic buffer is ...
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Why do buffer solution only maintain pH to a certain limit?
I know that buffers have a capacity after which they are not able to maintain a relatively stable pH. This capacity is exceeded when we add too much acid or base but I was wondering why does this ...
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Calculating the pH after adding hydrochloric acid to the potassium hydrogen phosphate solution
I am trying to calculate the $\mathrm{pH}$ of a solution obtained by mixing $\pu{20.00 mL}$ of $\pu{0.2 M}$ potassium hydrogen phosphate solution and $\pu{10.00 mL}$ of $\pu{0.25 M}$ hydrochloric acid ...
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What happens to the ions after dissociation in an aqueous solution? [closed]
I'm in high school studying about Buffer Solutions. We had an example of a solution made up of Ammonium Hydroxide and Ammonium Chloride for a Basic Buffer.
NH4OH ⇌ NH4 (+) + OH(-)
NH4Cl ⇌ NH4 (+) + ...
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Calculate the pH of a buffered solution after adding strong acid [closed]
Calculate the pH of a solution formed by the addition of $0.0020$ moles of $\ce{HCl}$ to $\pu{100.0 mL}$ of $\pu{0.200 M}$ $\ce{CH3NH2}$/ $\ce{0.100 M CH3NH3Cl}$.
$K_\mathrm{b}(\ce{CH3NH2})=4.4\times ...
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Sodium Citrate / Sodium Phosphate Buffer Calculations
I'm trying to work through the calculations of a specific paper (linked here / below) but, my numbers are way off and I can't get them to match for the life of me. I need to make the same buffer but ...
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What is the math behind the formula for the concentration of the strong titrant when calculating theoretical buffer capacity of a diprotic system?
I have a question related to finding the theoretical buffer capacity of a diprotic system, specifically about the formula for the concentration of the strong titrant. In this post:
What is the formula ...
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Exact calculation of pH of diprotic acid plus strong base
Another post has an excellent "exact" calculation for the [H+] (or pH) of a generic diprotic acid dissociating in water.
Combining acid dissociation constants to determine pH of diprotic ...
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pH and degree of dissociation of drugs
I have a doubt, i hope not so stupid.
Suppose we consider a buffer solution of acetic acid/acetate at pH = pKa = 4.76 and we add aspirin (pKa = 3.5): given that the pH of the solution is higher than ...
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What is the charge of amino acid in alkaline conditions?
This problem refers to the protein buffer in a living system.
"If the blood pH becomes alkaline, there is a release of a proton from the
$\ce{NH3+}$ ion, which takes the $\ce{NH2}$ form."
I ...
user131254
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Does temperature affect ionic strength?
Hello I apologize if this is a dumb question but if I have a phosphate buffer made up of Na2HPO4 and NaH2PO4 and I gradually increase the temperature (lets say 10,20,30,40,50) what would happen to the ...
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Measuring [A-]/[HA-] with Buffer and Indicator
I'm very confused on how to calculate the [A-]/[HA] value, given the fact that my dilution series uses buffers at various pH values with the same indicator (supplied at the same concentration to each ...
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Why doesn't the volume of NH3 = 325 ml in this problem? [closed]
I'm struggling with the problem below, and don't understand why
A buffer solution with pH = 9.0 is to be prepared from a 0.2 M ammonia
solution and a 0.15 M $\ce{HCl}$ solution. The sum of the molar
...
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Why does "bis-tris propane" have two pKa values?
Wikipedia gives two pKa values for "Bis-tris propane".
What about bis-tris-propane gives this compound two pKa values where other compounds have only one? How am I to choose which pKa value ...
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How to calculate the buffer capacity for polyprotic acids? specifically H2PO4 --- HPO42- + H30+
as the title says. Is b= amount of OH-/ H3O divided by volume of buffer x change in pH wrong to use with polyprotic acids? Can I calculate the buffering capacity of a sodium phosphate buffer made up ...
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Calculating acid volumes needed
I collect water quality samples used for irrigation. The samples are sent to a lab to measure $\ce{Ca^{2+}, Mg^{2+}, CO3^{2-}, HCO3^-}$, pH, and total dissolved solids.
I need to use acid to prevent ...
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What happens when you add a weak acid to a solution buffered at a pH of 8.0?
There are a lot of textbook examples showing what happens to the pH of a buffered solution when you add strong acids and strong bases. Searching for an example calculation where you add weak acids or ...
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Will the solid formed after dehydration of a disodium hydrogen phosphate + sodium hydroxide solution be hygroscopic at STP?
Given a solution consisting of disodium hydrogen phosphate + sodium hydroxide (approaching a pH of 12), will the solid formed after dehydration of the solution be hygroscopic at STP? Which salts are ...
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A method to create NH3-NH4Cl buffer solution using titration method
My aim is to create a basic buffer solution.
I know that to create a basic buffer solution, we need a strong acid and weak base. In my case I have chosen $\ce{NH3}$ and $\ce{NH4Cl}$.
Using titration, ...
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pH calculation of a mixure containing 2 strong acids and a buffer mixture
Calculate the pH of a mixtureof 10 mL 0,1 M HCl ; 5 mL 0,1 M HNO3 ; 10 mL 0,2 M HAc ; 15 mL 0,4 M NaAc.
My understanding was that I have to find the [H+] by:
finding the concentration of the products ...
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How to find pH for acetate buffer?
Calculate the pH of the solution that results when $\pu{40.0 mL}$ of $\pu{0.100 M}$ $\ce{CH3COOH}$ is mixed with $\pu{30.0 mL}$ of $\pu{0.200 M}$ $\ce{NaCH3COO}.$ $K_\mathrm{a}(\ce{CH3COOH}) = \pu{1....
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How to make NaxPO4 buffer?
I am currently trying to make a buffer for protein expression. According to the article, I am to use a buffer with $\pu{50 mM}$ $\ce{Na_{x}PO4}$, $\pu{pH 8}$ (and $\ce{0.5 M NaCl}$). How do I make the ...
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Finding dissolved amount of base from pH and solubility product
Calculate the amount of $\ce{Mg(OH)2}$ which is solubilized in $\pu{1.25 L}$ of a buffered solution at $\mathrm{pH} = 9.5$. $(K_\mathrm{sp}(\ce{Mg(OH)2}) = \pu{5.61E-12})$.
From $\mathrm{pH}$ I ...
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