All Questions
Tagged with equilibrium titration
39
questions
-2
votes
3
answers
343
views
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 ...
1
vote
0
answers
410
views
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
2
answers
629
views
Calculate the pH at the equilibrium point in an acetic acid sodium hydroxide titration
You perform a titration of $\ce{CH3COOH}$ with $\ce{NaOH}$. Let the original concentration of acetic acid be $\pu{0.2 M}$. The volumes of $\ce{CH3COOH}$ and $\ce{NaOH}$ are the same. Then the ...
- 45
3
votes
2
answers
2k
views
Calculate the titer of a solution
I hope this is the right place to ask. We have this exercise without solution
One litre of diluted sodium hydroxide solution (c = 0.15mol/litre) is
to be prepared in the laboratory. The titer from ...
- 423
-1
votes
1
answer
114
views
Why phenolphthalein is not completely neutralized in basic solutions? [closed]
Phenolphthalein $(\ce{HIn})$ is slightly acidic. Why doesn't it completely break down into $\ce{H+}$ and $\ce{In-}$ and also reacting with all of the $\ce{OH-}$ ion present, unlike $\ce{NaOH}$ and $\...
0
votes
0
answers
55
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Titration of a weak acid with a strong base
I recently learned that when titrating a strong base like NaOH into a weak acid, like Acetic Acid, a buffer region/zone develops and can be illustrated as follows:
CH₃COOH + OH⁻→ CH₃COO⁻ + H₂O
I've ...
-2
votes
2
answers
355
views
Acidity and Basicity of titrate and titrant in Acid-Base titration
I want to know that do we always use monoprotic acid and bases in the Acid-Base Titration. And, if the answer is No. Then, I am confused in the definition of Equivalence Point, because I had seen on ...
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
0
votes
2
answers
787
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Calculating the pH of a 'buffer' solution?
Question: Determine the $\mathrm{pH}$ of the solution resulting when $\pu{100 cm^3}$ of $\pu{0.50 mol dm-3}$ $\ce{CH2ClCOOH}$ is mixed with $\pu{200 cm^3}$ of $\pu{0.10 mol dm-3}$ $\ce{NaOH}$.
The ...
- 153
-3
votes
1
answer
5k
views
pKa = pH for strong acid — strong base?
I have learnt that for a weak acid — strong base titration, $\mathrm{p}K_\mathrm{a} = \mathrm{pH}$ at the half equivalence point.
However, the same conclusion is not drawn when discussing strong acid —...
- 153
0
votes
1
answer
783
views
Dissociation constant for Indicators
So I came across a question which asked to calculate the $\mathrm{pH}$ at which an indicator of given $\mathrm{K_{a}}$ would change colour. The solution was given in the following way
Since when the ...
1
vote
1
answer
236
views
What is an alternate way of preparing a sodium hydrogen phosphate/sodium dihydrogen phosphate buffer through titrating an acid with a strong base?
So my friend and I are stumped. This is in the context of achieving the sodium hydrogen phosphate/sodium
dihydrogen phosphate buffer by titrating the acid with a strong base.
My friend says the answer ...
- 19
1
vote
2
answers
5k
views
Which make HCO3- to show two pH values at two scenarios?
According to the below two titrations,
Image Reference
If we consider the reactions, at the first reaction (in first figure after adding 1.0), there is $\ce{HCO3-, NaCl,}$ and $\ce{H2O}$ at the first ...
- 633
4
votes
3
answers
253
views
Is pK_{In} = pH at equivalence point still true for weak basic organic indicators?
I am reading Ostwald Theory of Titration which says that indicators are organic weak acids or bases.
To prove the relation that $\mathrm{p}K_\mathrm{In} = \mathrm{pH}$, the textbook uses the following ...
- 261
5
votes
1
answer
439
views
Is chromate a suitable indicator for the titration of Ag⁺ with Cl⁻?
To titrate $\ce{Cl-}$ with $\ce{Ag+}$ we use chromate $\ce{CrO4^2-}$ as an indicator.
The titration reaction is:
$$\ce{Ag+ + Cl- <=> AgCl}\tag{R1}$$
$$K_1 = \frac{1}{K_\mathrm{sp}(\ce{AgCl})} =...
- 187
-1
votes
1
answer
2k
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How to calculate the equivalent mass of Na2S2O3? [closed]
Let us consider the following reaction
$$\ce{I2 + 2 Na2S2O3 -> 2 NaI + Na2S4O6}$$
Now, in order to calculate the equivalent mass of $\ce{Na2S2O3}$, first I need to calculate it's $n$-factor which ...
- 992
0
votes
1
answer
5k
views
How to calculate the equivalent weight of KMnO4?
Let us consider the following reaction
$$\ce{2 KMnO4 + 16 HCl → 2 KCl + 2 MnCl2 + 8 H2O + 5 Cl2}$$
Now, in order to calculate the equivalent mass of $\ce{KMnO4}$, first I need to calculate it's $n$-...
- 123
1
vote
1
answer
179
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{...
user62318
0
votes
1
answer
3k
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 ...
- 54
-2
votes
4
answers
7k
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Titration of Na2CO3 against HCl
$\pu{25 mL}$ of $\pu{0.125 M}$ $\ce{Na2CO3}$ is titrated with $\pu{0.100 M}$ $\ce{HCl}$. Given that $K_\mathrm{a1} = 4.3\times 10^{-7}$ and $K_\mathrm{a2} = 4.8\times10^{-11}$ for the diprotic acid $\...
- 51
1
vote
1
answer
488
views
Why doesn't pH = pKa1 in the buffer zone for this titration?
Below is an image from my textbook representing the titration curve for the titration of $5.00\ \mathrm{mL}$ of $0.010\ \mathrm M$ $\ce{H2S2O3}$ with $0.010\ \mathrm M$ $\ce{KOH}$, which has $\mathrm ...
- 2,109
0
votes
1
answer
12k
views
Find the half equivalence point
How to find the half equivalence point knowing the pH, molarity, titrant added at equivalence point?
This a fairly straightforward and simple question, however I have found many different answers to ...
1
vote
1
answer
2k
views
Is the amount of substance of acid and base always equal at the equivalence point?
Does the amount of substance of acid always have to equal the amount of substance of base at the equivalence point? I know it "works" for monoprotic acids and monobasic bases, but what if we had a ...
- 21
2
votes
1
answer
8k
views
Calculating the pH of the endpoint in a titration of weak acid and strong base
Show that the pH at the endpoint in the titration of $\mathrm{0.100\ mol\ dm^{-3}}$ ethanoic acid with $\mathrm{0.100\ mol\ dm^{-3}}$ sodium hydroxide is 8.72. The dissociation constant Ka of ethanoic ...
- 223
0
votes
2
answers
2k
views
Equivalence point of titration
Why is $\ce{[HIn] = [In-]}$ at equivalence point of a titration? I know that at equivalence point moles of known solution is equal to the moles of unknown solution, but I'm not able to relate that ...
- 412
3
votes
3
answers
6k
views
Phenolphthalein as a indicator for the titration of benzoic acid
Question: Justify the use of phenolphthalein $(\mathrm{p}K_\ce{in}=9.4)$ as a indicator for the titration of benzoic
acid $(K_\mathrm{a}=6.3\times 10^{-5})$ with $\ce{NaOH}$.
My attempt:
I can ...
- 151
2
votes
0
answers
2k
views
Titration curve, how to find equivalence point
If you have a graphed titration curve and have points near the equivalence point like
6.85 pH at 54.60mL titrant added and
8.01 pH at 54.73mL titrant added
is there any good way to find a more ...
- 21
0
votes
1
answer
1k
views
How to determine the hydroxide ion concentration in an acidic aqueous solution?
When doing a titration with $\ce{HCl}$ and $\ce{NaOH}$, both being strong and dissociating completely, if you add a volume of $\ce{NaOH}$ that is less than needed to reach the equivalence point, you ...
-1
votes
1
answer
41k
views
Titration curve graph, finding exact point of the equivalence point
I plotted all my data points and made this graph in excel. Now I need to find the volume of titrant required to read the equivalence point, as well as the pH after 18.5 mL of titrant have been added. ...
- 749
1
vote
2
answers
498
views
Concentration of a species outside buffer region (polyprotic acid titration)
I'm wondering if you titrate a polyprotic acid, say, $\ce{H3PO4}$, with a strong base, and you successfully pass the first equivalence point and are maybe at the $\mathrm{pH}=\mathrm{pK}_{a2}$ point ...
- 121