All Questions
20
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Calculating the pH of an exteremely dilute solution (3.6×10^-9 M) of weak acid [closed]
I've got a question about analytical chemistry that I'm having trouble solving:
For a $\pu{3.6 \times 10^{-9} M}$ solution of 1-naphthoic acid, calculate the $\mathrm{pH}$ $\left(K_\mathrm{a} = 2.1 \...
- 29
1
vote
1
answer
405
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Understanding weak acid-strong base titration
Today I stumbled across a website which defined the titration of weak acid and strong base as the following:
"The titration of a weak acid with a strong base involves the direct transfer of ...
user115162
0
votes
1
answer
73
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Approximation for pH calculation with diluted acids in weak-strong titration curve
I was wondering how one could calculate small pH changes in titrations with dilute acids.
As we know, usually we approximate the pH by saying that the conversion is quantitative. For example, when we ...
user115162
0
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0
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856
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What reaction is used for calculating pH of the solution obtained after ethanol oxidation with potassium permanganate?
If $\pu{30.0 ml}$ of $\pu{0.20 M}$ ethanol solution reacts with $\pu{1.80 g}$ potassium permanganate, what will be the final $\mathrm{pH}$ of the solution? Assume a complete reaction and that only the ...
- 9
-2
votes
1
answer
745
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How much NaOH I have to add to increase pH?
I'm stuck in solving this problem. I have two solution of $\pu{5 M}$ $\ce{H2SO4}$ that needs two consequential $\mathrm{pH}$ increasing: the first from the natural $\mathrm{pH}$ of $\pu{5 M}$ $\ce{...
1
vote
1
answer
370
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How do you find the pH of lime juice through titration?
I am doing an experiment on the effect of time on the $\mathrm{pH}$ of Lime juice.
I was wondering how you would calculate the $\mathrm{pH}$ through titrations using $\pu{1 Molar}$ $\ce{NaOH}$. I have ...
- 339
0
votes
2
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1k
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Why is H⁺ ion considered the source of acidity, and OH⁻ considered the source of basicity? [closed]
As the title implies, what caused the association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and basicity?
- 157
0
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3
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158
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How to simplify these system of equilibrium equations
What is the pH when $0.025$ mol $\ce{NiCl2}$ is added to $\pu{1.00 L}$ of a $\pu{0.100 M}$ solution of $\ce{HCN}$, if the formation constant for $\ce{Ni(CN)4^2-}$ is $K_f=\pu{1.0e22}$, and the $K_a$ ...
- 2,109
1
vote
1
answer
2k
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Preparation of acetate buffer from sodium acetate and hydrochloric acid
A $\pu{1.0 L}$ buffer solution of $\mathrm{pH}~4.43$ is made up of $\pu{0.30 M}$ sodium ethanoate and $\pu{0.20 M}$ $\ce{HCl}$ solutions. Calculate the volume of sodium ethanoate and $\pu{0.20 M}$ $\...
1
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0
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43
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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 ...
- 21
1
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2
answers
2k
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Calculating the pH of a buffer made by a diprotic acid and its double salt
The concentration of the diprotic acid (tartaric acid) will be constant at $\pu{ 0.1 M}$. I want to find the concentration of its double salt (potassium sodium tartrate) needed to create a buffer of $\...
- 103
3
votes
1
answer
1k
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What is the formula for theoretical buffer capacity for a diprotic buffer system?
According to Chembuddy, the formula for theoretical buffer capacity for a monoprotic buffer system is as follows:
$$β = 2.303\left(\frac{K_\mathrm{w}}{[\ce{H+}]} + [\ce{H+}] + \frac{C_\mathrm{buf}...
- 103
2
votes
1
answer
829
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Why is maximum buffer capacity for some diprotic buffers not when pH = pKa?
According to Rajkovic et al. [1]:
$$β = \frac{[\ce{H+}]}{K_\mathrm{w}} + 2.303\cdot\frac{[\ce{H+}]\cdot K_\mathrm{a}\cdot c}{[\ce{H+}] + K_\mathrm{a}}$$
where $K_\mathrm{a}$ is the dissociation ...
- 103
0
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1
answer
1k
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Effects of Ka on the Half-Equivalence Point
I'm new to studying chemistry at a university level and am currently reviewing acid-base titrations. I am wondering about the relationship between your ionization constant for a weak acid ($K_\mathrm{...
5
votes
2
answers
340
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Should the tip of the burette of an automatic titrator be immersed in the analyte?
In all the tutorials I found online, the tip of the burette (containing the titrant - NaOH) was immersed into the analyte solution. My question is: shouldn't the tip be out of the solution? Isn't ...
- 151