All Questions
Tagged with equilibrium analytical-chemistry
26
questions
9
votes
2
answers
8k
views
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.
$\mathrm{pK_{a1}} = 3.09~~~~~ \mathrm{pK_{a2}} = 4.75~~~~~ \mathrm{pK_{a3}} = 6.40$
...
- 7,402
6
votes
1
answer
111
views
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
$$D = \frac{C_\mathrm{A}(\text{ext})}{C_\mathrm{A}(\text{orig})}$$ ...
- 71
6
votes
1
answer
7k
views
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 ...
- 71
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:
$$\ce{Ag+ + Cl- <=> AgCl}\tag{R1}$$
$$K_1 = \frac{1}{K_\mathrm{sp}(\ce{AgCl})} =...
- 187
3
votes
0
answers
331
views
The behaviour of Ag3PO4 in solution
To a $\pu{1L}$ flask, we add $\pu{4.1900 g}$ ($\pu{0.01001 mol}$) of $\ce{Ag3PO4}$, then fill it up with water. Knowing the following constants, we are asked to find the concentration of all species ...
- 587
2
votes
2
answers
131
views
Multiple equilibria
I was reading about multiple equilibria reactions and can't quite comprehend some things.
Suppose we have two reactions:
\begin{align}
\ce{A + B &<=> C + D},& K_\mathrm{eq} &= 10^{20}...
- 383
2
votes
0
answers
40
views
Is the amine nitrogen of methylglycinediacetic acid (MGDA) protonated?
MGDA is a tertiary amine with 3 acetic acid groups. I would like to know whether the amine Nitrogen of MGDA is protonated or not for a given pH value. I could not find any literature data which ...
- 29
2
votes
0
answers
110
views
Calculating Ka using Nernst Equation
I've heard multiple times that the Nernst Equation could be used to calculate K$_a$. How would one calculate the acidity constant, K$_a$, of a specific acid, using the Nernst Equation? The equilibrium ...
2
votes
0
answers
547
views
Apparent solubility of Ag2C2O4 in a buffer solution
We take the following quantities and mix them together:
$\pu{20 mL}$ solution of $\ce{AgNO3}$ $\pu{0.001 mol//dm3}$
$\pu{20 mL}$ solution of $\ce{H2C2O4}$ $\pu{0.200 mol//dm3}$
$\pu{40 mL}...
- 587
2
votes
0
answers
143
views
How to calculate concentrations when dissolving two salts?
Some solid silver bromate was dissolved together with solid silver acetate what would be the highest achievable pH?
\begin{align}
K_\mathrm{sp}(\ce{AgBrO3}) &= 5.38 \times 10^{-5}\\
K_\mathrm{sp}...
- 7,402
1
vote
2
answers
2k
views
Calculating solubility of iron(III) hydroxide in water
The following example in Skoog's Analytical Chemistry uses mass-balance and charge-balance equations to calculate the solubility of iron(III) hydroxide in aqueous solution.
$$
\begin{align}
\ce{Fe(...
- 811
1
vote
1
answer
70
views
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 ...
- 11
1
vote
2
answers
2k
views
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
1
vote
2
answers
1k
views
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....
- 183
1
vote
0
answers
32
views
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 ...
