All Questions
Tagged with equilibrium acid-base
68
questions
125
votes
7
answers
87k
views
Is a negative pH level physically possible?
A friend of mine was looking over the definition of pH and was wondering if it is possible to have a negative pH. From the equation below, it certainly seems mathematically possible—if you have a $1.1$...
- 1,369
-1
votes
2
answers
1k
views
Calculate pH of a mixture of a strong base and acid. Knowing only the pH, wt/v%, and volume of both solution. [closed]
Title explains all. I have been stuck on this for an hour and for some reason cannot understand it. I have tried to do an ICE table but get stuck halfway as I do not know whether I would use the w/v ...
9
votes
4
answers
4k
views
Why does the inverse relationship between the strengths of an acid and its conjugate base appear to be violated in the case of chloric(I) acid?
Hypochlorous acid is a weak acid with $\mathrm{p}K_\mathrm{a}(\ce{HClO}) = 7.53$. Then why is its conjugate base, $\ce{ClO-}$, a weak base in water? Shouldn't the strength of the base be inversely ...
- 205
21
votes
3
answers
17k
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Does the number of H+ ions in solution go up on dilution of a weak acid?
In my textbook, a footnote says:
In case of weak acids, on dilution the total number of $\ce{H^{+}}$ ions in solution increases because dissociation of the weak acid increases
This didn't make ...
- 3,479
15
votes
2
answers
17k
views
What is the Ka of OH- and Kb of H3O+?
What is the $K_\mathrm{a}$ of $\ce{OH^-}$ and $K_\mathrm{b}$ of $\ce{H_3O^+}$? Have these constants been determined?
- 14.4k
13
votes
3
answers
9k
views
How can the equilibrium shift, while Kc remains constant?
Consider the following reversible reaction.
$$\ce{Cr2O7^2-(aq) + H2O(l) <=> 2 CrO4^2-(aq) + 2 H+(aq)}$$
What will happen to the position of equilibrium and the value of $K_c$ when more $\ce{H+}$ ...
- 557
10
votes
2
answers
26k
views
Why is water not part of the equilibrium constant?
In the acid base reaction
$$\ce{NH4+ + H2O <-> NH3 + H3O+}$$
the acidity constant, which is a relation between concentrations is given by
$$K_{\mathrm{a}}=\frac {\ce{[NH3]} \cdot \ce{[H3O+]}}{...
- 413
15
votes
2
answers
2k
views
How is volatility useful in the production of acids?
Sulfuric acid because of its low volatility can be used to manufacture more volatile acids from their corresponding salts.
How does volatility affect the production of acids? Isn't it that sulfuric ...
- 3,487
9
votes
3
answers
6k
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Find the pH of an amphiprotic salt dissolved in water at room temperature
Let's say I have a polyprotic acid $\ce{H2A}$ with the following properties:
$$
\begin{align}
\ce{H2A &<=> HA- + H+} & K_1 &= 1\cdot 10^{-1}\\
\ce{HA- &<=> A^2-+ H+} & ...
- 201
12
votes
5
answers
41k
views
How to determine the pH of a mixture of two weak acids?
We have two solutions:
Solution 1 is $\ce{HCOOH}$, its concentration is $c_1 = \pu{10^-2 mol/l}$, its volume is $V_1 = \pu{50 ml}$, and its $\mathrm{pH}_1 = 2.9$.
Solution 2 is $\ce{CH3COOH}$, its ...
- 121
2
votes
2
answers
2k
views
How concentrated can an acid be?
How concentrated can an acid be without it being supersaturated? Is there a certain limit to how concentrated an acid or base can be?
When I mean concentration, I mean molarity; so how concentrated ...
- 3,050
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
0
votes
2
answers
12k
views
pH of ammonium acetate solution
I'm trying to calculate the pH of a 1M $\ce{NH_4CH_3COO}$. I know that I'll have these reactions:
$\ce{NH_4CH_3COO <=> NH_4^+ + CH_3COO^-}$
$\ce{NH_4^+ <=> NH_3 + H^+}$
$\ce{CH_3COOH <=...
- 3
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
8
votes
2
answers
10k
views
Why is ortho-hydroxybenzoic acid more acidic than its para-isomer?
Why is ortho-hydroxybenzoic acid $(\mathrm{p}K_\mathrm{a} = 2.98)$ more acidic than its para-isomer $(\mathrm{p}K_\mathrm{a} = 4.58)$?
March's Advanced Organic Chemistry (7th ed) gives the reason to ...
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