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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Can carbon monoxide become entrained in water, and will it affect the pH of that water? [on hold]
A hot gas containing $\ce{CO2}$ and $\ce{CO}$ will pass through a water cooler. I know that $\ce{CO2}$ can be dissolved in the water, form carbonic acid, and lower the $\mathrm{pH}$ of the water. Will ...
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1answer
49 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 ...
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1answer
27 views
Calculating amount of base needed to achieve a specific pH in a mixed ethanol-water solvent
I'm looking for some way to calculate how much base I will need to add to an unbuffered solvent consisting of a mixture of ethanol and water in order to basify it to a specific reading (10) on an a pH ...
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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 ...
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1answer
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Acid/Base Indicator [on hold]
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?
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1answer
25 views
Calculating the pH of Strong Acid Solutions [on hold]
Calculate the $\mathrm{pH}$ of a $\pu{1.5e–11 M}$ solution of $\ce{HCl}.$ How is the $\mathrm{pH}~7?$
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1answer
66 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 $...
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What is the pH value of 0.8M CuSO4 [closed]
really need to know how 0.8M CuSO4 will influence the acidity of
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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 ...
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27 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 ...
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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
$\ce{NH4Cl -> NH4+ + Cl-}$
$\ce{HCl -> H+ + Cl-}$
...
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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 ...
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1answer
100 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 $...
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1answer
46 views
Can I use litmus paper to test unknown liquid that contains a concentrated strong acid?
Can I use litmus paper to test unknown liquid that contains a concentrated strong acid (example $\ce{H2SO4}$)? Can concentrated strong acid destroy litmus paper?
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1answer
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Will strong concentrated acid destroy litmus paper and pH paper if they are dipped in acid?
I am curious to know what will happen if I have litmus paper and pH paper, and I dip them into strong concentrated acid like conc. $\ce{H2SO4}$ to test its acidity or basicity. Will acid destroy ...
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1answer
44 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 ...
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Can Acids have pH of more than 7? [duplicate]
Consider a solution of $\text{HCl}$ with a concentration of $10^{-10}$ $\text{M}$. Now, if I find it's pH:
$$\text{pH} = -\log([\text{H}^+])$$
$$\text{pH} = -\log(10^{-10}) = 10$$
At room temperature, ...
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Consider a “buffer” prepared from 0.15 M HCl and 0.100 M Cl-
I am given the following equation:
$$\ce{HCl(aq) + H2O(aq) <=> Cl-(aq) + H3O+(aq)}$$
where the molarity of $\ce{HCl}$ is $0.15$ and the molarity of $\ce{Cl-}$ is $0.1000$ and the $\mathrm pK_\...
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Measuring pH in ferric oxalate solutions
I have a problem with measuring $\mathrm{pH}$ in ferric oxalate solutions ($\sim 5~\text{to}~\pu{10 g L-1}$ $\ce{Fe},$ $\pu{0.8 M}$ oxalic acid, $\pu{25 °C}$). While I am sure about the $\mathrm{pH}$-...
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43 views
Calculation of resultant pH
A solution with $\mathrm{pH}=4$ is mixed with a solution with $\mathrm{pH}=10$ in equal volumes. Calculate resultant $\mathrm{pH}$.
Please note both solution consists of strong acids and/or bases i....
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1answer
50 views
Calculate the pH of buffer solution
PROBLEM: A solution was prepared by mixing $\pu{25.00 mL}$ of $\ce{NaOH}$ $\pu{(c = 1mol/L)}$ and $\pu{10.00 mL}$ of acetic acid $\pu{(c = 2.5 mol/L)}$ in water to give $\pu{250 mL}$ of solution.
...
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1answer
47 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 ...
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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-} &...
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Is it possible to raise pH in RO water without Na, Mg, K, Ca, S addition?
Maybe the question in the title is simple (=stupid) and the answer is 'simple No' but I have the urge to ask.
Some background, I have an aquarium which I use RO water and I use some portions of $\ce{...
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2answers
74 views
pH of strong acid weak acid mixture [closed]
Question: $\ce{H2S}$ ($\pu{0.1M}$; $K_\mathrm{a} = 1.2×10^{-20} $) and $\ce{HCl}$ ($\pu{0.3M}$) with same volume are mixed together. What is the resultant $\mathrm{pH}$?
My approach:
Let the volume ...
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1answer
41 views
Calculating molecular weight of an acid based on given values of mass, volume, pH and pKa
This is what I thought was an easy problem but according to a given answer I am doing it wrong:
$\pu{11 mg}$ of a monoprotic acid was dissolved in $\pu{0.5 l}$ of water. The resulting $\mathrm{pH}$ ...
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1answer
119 views
Why do weak acids like ethanol not act as a strong base in water?
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 ...
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1answer
69 views
Calculating the ph of an unknown solution by measuring the precipitate [closed]
You have an unknown metal hydroxide, but no meters or indicators. You have lead (II) nitrate, which is soluble in it, and lead (II) hydroxide that is insoluble in it. You take one liter of the unknown ...
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Calculating pH of solution
What is the $\mathrm{pH}$ when you dissolve equal amounts of $\ce{NaHCO3}$ and $\ce{Na2CO3}$ in water?
When both of the compounds are dissolved, we will have equal amounts of $\ce{HCO3-}$ and $\ce{...
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1answer
38 views
Calculating pH of weak base and strong acid: Why is K(a) not required?
Question: 35mL of 1.5M $\ce{HCN}$, a weak acid(K(a)= $6.2*10^{-10}$) is mixed with 25mL of 2.5M $\ce{KOH}$. Calculate the pH of final solution.
The solution given in my textbook is as follows:-
$\ce{...
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1answer
34 views
Could this solution be resolved by titration?
I have a mixture of $\ce{NH_4NO_3}$ and $\ce{NH_3}$ at $\ce{pH}$ of about 13.
It is possible to determine the concentration of both on them by acid-base titration?
I was told it's possible, and that ...
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1answer
29 views
When there is an increase in temperature, how is the pH of the ocean affected? (Question is related to ocean acidification)
This is my current understanding:
Ocean acidification is the result of atmospheric $\ce{CO2}$ dissolving in the ocean's water. When this occurs the $\mathrm{pH}$ of the ocean decreases (from the ...
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1answer
30 views
pKa value of an indicator
Can we deduce the actual value of $\mathrm{p}K_\mathrm{a}$ of an indicator if the $\mathrm{pH}$ range has been given?
I know that $\mathrm{pH}$ range is physically the range of values over which an ...
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2answers
44 views
Citric acid and ammonium nitrate
Soil based question. I have soil with to much Ammonium Nitrate in it. I am wondering if I use citric acid and water mixed will that flush out the extra Ammonium Nitrate that has built up in the soil.
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2answers
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Can I use the Henderson–Hasselbalch for calculating the pH of non-buffer systems?
Can I use the Henderson–Hasselbalch equation on reactions that are not buffers? When I read up on the derivation of the equation, I noticed that there is absolutely no assumption on the relative ...
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0answers
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Impact of pH? Change in Binding Affinity of protein-ligand complex based on pH and Kd?
When the $\mathrm{pH}$ was $5.0$, the temperature was $\pu{25 °C}$,the $K_\mathrm{D}$ was $\pu{5 μM}$, and [L] was equal to $K_D$, the protein(s) were half bound.
If $K_\mathrm{D} = \pu{20 μM}$ ...
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1answer
52 views
pH After Titration
50mL $\ce{SO2}$ titrated with 0.1M of $\ce{KBrO4}$ with reaction: $$\ce{KBrO4 + 4SO2 + H2O -> 4H2SO4 + KBr}$$ The equivalent point is reached when the volume of $\ce{KBrO4}$ is used as much 50mL. ...
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1answer
185 views
How accurately does (pKa1 + pKa2) / 2 estimate the pH of an amphoteric salt?
This question came up when answering Find the pH and amphiprotic salt is added to water at room temperature. If we dissolve $\ce{NaHA}$ in water, the species $\ce{HA-}$ can act as acid or base:
$$
\...
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3answers
573 views
Can solid acids and bases have pH values? If not, how are they classified as acids or bases?
This answer states
$\mathrm{pH}$ is the aqueous concentration of $\ce{H3O+}$ or $\ce{H+}$ ions in soution. I would not say that ice lacks $\ce{H3O+}$ and $\ce{OH-}$ ions as ice's structure would ...
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1answer
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At what acid concentration does potassium metabisulfite react?
I'm in the process of developing a well preserved food-stuff containing potassium metabisulfite and a number of acids (acetic, ascorbic, malic, tartaric, citric, lactic). Wine-making literature ...
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1answer
128 views
pH of CH3COOH + HCl solution (shouldn't be a buffer)
$\pu{0.05 L}$ of a solution containing $\pu{0.3 M}$ acetic acid $(\ce{CH3COOH}$, $K_\mathrm{a} = \pu{1.8e-5})$ are added to $\pu{75 mL}$ of a solution containing $\pu{0.02 M}$ hydrochloric acid ($\ce{...
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1answer
116 views
pH of a Calcium Hydroxide vs Magnesium Hydroxide solution [closed]
In an AQA 2017 Chemistry paper, a $0.0131 \pu{mol}\cdot\pu{dm^-3}$ saturated solution of calcium hydroxide is prepared and then the question asks to predict the pH of a similar solution of magnesium ...
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6answers
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How to calculate pH of basic salt solution mixed with strong base?
Calculate $\mathrm{ pH }$ of $\pu{ 0.05 mol }$ of $\ce{Zn(CH3COO)2}$ and $\pu{ 0.025 mol }$ of $\ce{ NaOH }$ dissolved in $\pu{ 1 L }$ of distilled water?
I tried to use the systematic method by ...
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1answer
91 views
How do I calculate the hydronium ion concentration if I know the strontium hydroxide concentration?
This is my first question so I would appreciate feedback on how to ask better questions. Forgive me if I don't know how to properly format math/chem. The guide is confusing.
I was taking a practice ...
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2answers
49 views
Calcium Phosphate Dissolution
For what reason does Calcium Phosphate dissolute at low pH? What makes it pH dependent? This question arised after reading about the calcium phosphate bridges in casein micelles and how they 'break ...
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1answer
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By how many pH units does rain vs distilled water change a soil pH test?
Sources state that the concentration of $\ce{H2CO3}$ in rain is of a few µmol; I don't know if that's per ml. The buffering effect of most soils is >1000 µmol $\ce{H+}$/kg.
Is the difference from low ...
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0answers
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Preparation of Copper (II) Sulfate Pentahydrate Solution
how would you make a solution of Copper (II) Sulfate Pentahydrate to achieve 150, 200, 250 and 300 mgL−1 concentration of copper? I do not have the anhydrous version of the solute. Also, when I ...
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2answers
23 views
Influence of pH on precipitate crystallite sizes?
It's normally assumed that a higher pH of solution would slow nucleation rates and hence lead to larger crystal formation. I've found literature that it is due to solid-liquid inter-facial tension. ...
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Naming convention for buffer solutions/systems
Is there an official naming convention to follow for buffer solutions/systems? I've noticed that the name of the buffer usually just follows the name of the salt (ex. sodium acetate buffer), but what ...
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1answer
37 views
Reference Books on Electrolysis and Chemical Titration process [closed]
I'm in a General Chemistry course in college. We have laboratory, and then we are supposed to make a report on what we did, etc.
I'm not entirely sure what the last laboratory was about, but it was ...
