All Questions
Tagged with equilibrium ph
22
questions with no upvoted or accepted answers
5
votes
0
answers
479
views
Why does pKw first decrease but eventually increase when temperature rises?
I understand the initial decrease in pKw.
$\ce{Heat + H2O (l) <=> H+ (aq) + OH- (aq)}$
Temperature increases, reaction shifts to the right, so
$\ce{H+} \text{ and } \ce{OH}$ ...
- 2,853
4
votes
0
answers
74
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Decomposition of Hydrogen Peroxide Catalysed by Potassium Iodide in Basic Solution
As part of my high school project, I had to measure the initial rate of decomposition of hydrogen peroxide catalysed by potassium iodide at different pHs. At higher pHs (alkaline conditions), I found ...
- 41
2
votes
0
answers
143
views
How to calculate concentrations when dissolving two salts?
Some solid silver bromate was dissolved together with solid silver acetate what would be the highest achievable pH?
\begin{align}
K_\mathrm{sp}(\ce{AgBrO3}) &= 5.38 \times 10^{-5}\\
K_\mathrm{sp}...
- 7,402
1
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0
answers
41
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How to calculate the pH of a mixture of an acid with a buffered solution?
Being a physicist by training, having worked in software development for the last 10 years. Having heard my last chemistry lecture 15 years a go I am a bit lost in regards to how one can calculate the ...
- 111
1
vote
0
answers
410
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Determine the pKa of a diprotic acid by titration (if pKa1 is similar to pKa2)
Determining the acidity constants of a diprotic acid (in my case, tartaric acid) by titration with NaOH and pH-meter is not possible if pKa2 - pKa1 < 2.
This is because there are no "pH jumps&...
- 109
1
vote
0
answers
254
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How to calculate pH of a 0.1 M solution of ammonium bicarbonate considering simultaneous equilibrium along with hydrolysis?
We need to calculate the $\ce{[H+]}$ of 0.1M $\ce{(NH4+)(HCO3^-)}$ given the $\ce{k_b(NH4OH), k_{a_1}(H2CO3), k_{a_2}(HCO3^-)}$
The hint tells me to directly use the result $\ce{[H+]=\sqrt{k_{a_1}(\...
- 35
1
vote
0
answers
105
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How does pH affect an extraction problem
I am not sure how to understand when pH will affect a given problem regarding extraction. For example, in a problem given that K$_D$ of the reaction is $1.86$ I am asked to calculate:
(a) How much ...
- 1,095
1
vote
0
answers
485
views
Equivalence point pH derivation of a tribasic acid
Considering $\pu{100 mL} \ \pu{0.1 M} \ \ce{H3A}$ and $\pu{0.1 M} \ \ce{NaOH}$ titration curve:
I understood the half equivalence points, but couldn't understand the reason why $\mathrm{pH} = \frac{1}...
- 412
1
vote
0
answers
570
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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.
Question considers half bound ...
1
vote
0
answers
222
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Calculating the pH of a weak acid from the Kb of its conjugate base
I'd start off by saying it's been many years since I was in chemistry lessons and have forgotten much, but recently I have had to relearn a lot of basic chemistry. The following doesn't really impede ...
- 111
1
vote
0
answers
321
views
Henderson-Hasselbalch approximation
The Henderson-Hasselbalch approximation gives us a method to approximate the pH of a buffer solution. The basic equation is as follows:
$$\mathrm{pH} \approx \mathrm{p}K_\mathrm{a} + \log\dfrac{\ce{[A^...
- 303
1
vote
0
answers
593
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Why does [H3O+] of a buffer change very slightly when diluted?
I am confused as to why the [H3O+] of a buffer changes very slightly when diluted (at least in an intuitive sense).
Consider:
$\ce{HNO2 + H2O <=> H3O+ + NO2-}$
[$\ce{HNO2}$] = 0.45 M and [$\...
- 59
1
vote
0
answers
778
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How to find pH of an aqueous ammonia solution at high pressures?
Here's the simplified question: I start with $15~\%$ of $\ce{NH_3}$ and I want to find the $\mathrm{pH}$ of the following reaction at $25~\mathrm{^\circ C}$ and $5\ \mathrm{kbar}$:
$$\ce{NH_3 + H_2O -&...
- 11
1
vote
0
answers
374
views
Find H3O+ of weak acid salt solution which compose of solute that can gain and give protons
Find $[\ce{H3O+}]$ of 0.100 M $\ce{NaHCO3}$ ($K_{\ce{H2CO3},1}=4.45×10^{-7}$, $K_{\ce{H2CO3},2}=4.7×10^{-11}$)
My work is: $$\ce{HCO3- + H2O<=>H2CO3 + OH-}$$
Initial: $[\ce{HCO3-}]$ = 0.100 M, ...
- 107
1
vote
1
answer
131
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Hydrolysis of a salt B2X
An aqueous solution of soluble salt $\ce{B2X}$ has concentration of 0.1 M.
Given data :
$\ce{K_b(BOH) = 2 × 10^{–5}}$
$\ce{K_{a1}(H2X) = 2 × 10^{–7}}$
$\ce{K_{a2}(H2X) = 5 × 10^{–10}}$
...
