All Questions
Tagged with equilibrium analytical-chemistry
26
questions
1
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0
answers
32
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Iodine/iodide electrochemistry help
I have an electrochemistry experiment with iodine in solution.
I am initially wanting to quantify the iodide in solution and extrapolate the concentration of I2(aq) and I3-(aq) in solution from this ...
2
votes
2
answers
131
views
Multiple equilibria
I was reading about multiple equilibria reactions and can't quite comprehend some things.
Suppose we have two reactions:
\begin{align}
\ce{A + B &<=> C + D},& K_\mathrm{eq} &= 10^{20}...
2
votes
0
answers
40
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Is the amine nitrogen of methylglycinediacetic acid (MGDA) protonated?
MGDA is a tertiary amine with 3 acetic acid groups. I would like to know whether the amine Nitrogen of MGDA is protonated or not for a given pH value. I could not find any literature data which ...
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}(\...
1
vote
1
answer
70
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An Index Poisoning Case Involving Dichlor and Carbonic Acid [closed]
I'm currently working an unusual case of poisoning, with Sodium Dichloro-S-Triazinetrione.
In my case, I need to know the expected reaction with carbonic acid.
I'm also curious if anyone could give ...
0
votes
2
answers
2k
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How much Na2O (from NaOH) do I add to sodium silicate with a weight ratio of SiO2/Na2O = 2.34 to get the solution to a weight ratio SiO2/Na2O = 1.9?
There is some confusion in industry as sodium silicate is made with NaOH but given a ratio with respect to Na2O (i.e. SiO2/Na2O not SiO2/NaOH). I presume it follows from this equation:
2NaOH -> ...
0
votes
1
answer
38
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Disparity between LeChatelier's Principle and Solutions
Let's say that there is a solution
$\ce{Na+(aq) + Cl-(aq) <=> NaCl(s)}$
If the above solution is at equilibrium we can say that it is saturated and hence no more Sodium Chloride will dissolve. ...
0
votes
0
answers
138
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Problem in the calculation of ionic strength of a solution
Recently I've been trying to answer the question 10-13 (c) of 9th edition of Fundamentals of Analytical Chemistry of Skoog et al. Comparing my answers with the student manual , I realized that my ...
2
votes
0
answers
110
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Calculating Ka using Nernst Equation
I've heard multiple times that the Nernst Equation could be used to calculate K$_a$. How would one calculate the acidity constant, K$_a$, of a specific acid, using the Nernst Equation? The equilibrium ...
0
votes
3
answers
2k
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Activities and molar concentrations
I would be really happy if someone would clarify the term "chemical activity" and its implications for me, and also how it is related to the concept of molar concentration. My textbook fails at ...
0
votes
1
answer
877
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Nernst equation and equilibrium
I am currently stuyding electrochemistry, and recently I've stumbled upon a problem where one is supposed to calculate the concentration of Fe3+ ions after a solution containing Fe2+ was titrated ...
0
votes
0
answers
29
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How to account for the common ion effect on osmolarity quantitatively?
In adjusting the osmolarity of a solution of Benzalknonium Cl, Disodium Editate, and Disodium borate/boric acid buffer to be isotonic (about 290 mOsm), the addition of NaCl showed unexpected behavior, ...
0
votes
3
answers
158
views
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 $K_a$ ...
5
votes
1
answer
439
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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:
$$\ce{Ag+ + Cl- <=> AgCl}\tag{R1}$$
$$K_1 = \frac{1}{K_\mathrm{sp}(\ce{AgCl})} =...
1
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2
answers
2k
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Calculating the pH of a buffer made by a diprotic acid and its double salt
The concentration of the diprotic acid (tartaric acid) will be constant at $\pu{ 0.1 M}$. I want to find the concentration of its double salt (potassium sodium tartrate) needed to create a buffer of $\...
-1
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2
answers
2k
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Equilibrium constant for esterification process
Teacher told us that the concentration term for pure liquids and solids is always $1$. But online I found this reaction:
$$\ce{CH3COOH(l) + CH3CH2OH(l) <=> CH3COOCH2CH3(l) + H2O(l)}$$
...
6
votes
1
answer
111
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Distribution coeffecient without concentrations
From what I understand about distribution coefficient is straight from my book — which does not give any practice examples — is that
$$D = \frac{C_\mathrm{A}(\text{ext})}{C_\mathrm{A}(\text{orig})}$$ ...
1
vote
2
answers
2k
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Calculating solubility of iron(III) hydroxide in water
The following example in Skoog's Analytical Chemistry uses mass-balance and charge-balance equations to calculate the solubility of iron(III) hydroxide in aqueous solution.
$$
\begin{align}
\ce{Fe(...
0
votes
1
answer
71
views
Volume of NaOH needed to precipitate copper(II) but not calcium
I have $\ce{NaOH}: C = \pu{0.1M}, V_{\ce{NaOH}}$ that I want to progressively add in a solution (in water) of:
$$\begin{align}
\ce{Cu^{2+}}&: \pu{0.01M}; & K_\mathrm{sp} &= 10^{-18.6} \\
\...
1
vote
2
answers
1k
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Kc(equilibrium constant) and Kp
Its given in the book that at 12.18kelvin Kc=Kp. How is that equated from the equation Kp= Kc(RT)^∆ng. I am unable to sort it out, please guide me in to the topic....
3
votes
0
answers
331
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The behaviour of Ag3PO4 in solution
To a $\pu{1L}$ flask, we add $\pu{4.1900 g}$ ($\pu{0.01001 mol}$) of $\ce{Ag3PO4}$, then fill it up with water. Knowing the following constants, we are asked to find the concentration of all species ...
2
votes
0
answers
547
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Apparent solubility of Ag2C2O4 in a buffer solution
We take the following quantities and mix them together:
$\pu{20 mL}$ solution of $\ce{AgNO3}$ $\pu{0.001 mol//dm3}$
$\pu{20 mL}$ solution of $\ce{H2C2O4}$ $\pu{0.200 mol//dm3}$
$\pu{40 mL}...
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}...
9
votes
2
answers
8k
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Short Cut Method to Calculating pH of Polyprotic Acid?
I am doing the following question:
Calculate the pH of a $4.00\ \mathrm{mol\ L^{-1}}$ solution of citric acid.
$\mathrm{pK_{a1}} = 3.09~~~~~ \mathrm{pK_{a2}} = 4.75~~~~~ \mathrm{pK_{a3}} = 6.40$
...
6
votes
1
answer
7k
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Difference in calculated pH and the real pH of a phosphate buffer
I want to prepare a buffer system with $\mathrm{pH} = 7.00$ and a total concentration $c_\mathrm{tot} = \pu{0.10 mol l^-1}$ using sodium hydrogen phosphate $(\ce{Na2HPO4})$ and sodium dihydrogen ...
1
vote
1
answer
437
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Analytical Chemistry Textbook Recommendation [duplicate]
Could anyone recommend a good book for self-learning that provide a clear, step by step guide on solving such chemical equilibria questions.
It should cover the following topics: weak acid and ...