All Questions
Tagged with equilibrium acid-base
357
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
26
votes
4
answers
3k
views
What software can calculate aqueous solution equilibria?
What software is available out there to calculate the equilibrium in a set of reactions in aqueous solution? In particular, I'm interested in software general enough to simulate things like titration ...
- 23.8k
21
votes
3
answers
17k
views
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
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
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
15
votes
3
answers
11k
views
Why are weak acids weak?
What are weak acids? My chemistry and biology classes skimmed over them briefly but nothing in depth. I understand that an acid is weak if it partially dissociates and breaks down into ionic compounds,...
- 559
15
votes
4
answers
21k
views
Is LiOH a weaker base than NaOH?
Is $\ce{LiOH}$ a weaker base than $\ce{NaOH}$?
Note: I'm not interested in "why," but rather what the "real" $\mathrm{p}K_
\mathrm{b}$ values are.
$$
\begin{array}{lcc}
\text{Data for Alkali Metal ...
- 22.3k
13
votes
3
answers
9k
views
How can the equilibrium shift, while Kc remains constant?
Consider the following reversible reaction.
$$\ce{Cr2O7^2-(aq) + H2O(l) <=> 2 CrO4^2-(aq) + 2 H+(aq)}$$
What will happen to the position of equilibrium and the value of $K_c$ when more $\ce{H+}$ ...
- 557
13
votes
2
answers
8k
views
Why does the ionic product of water remain constant after addition of non-neutral solute?
In my textbook, it is given that the ionic product of water $K_\mathrm{w}$ remains constant even when a non-neutral solute such as an acid is added to it.
$$K_\mathrm{w} = \ce{[H3O+][OH-]}$$
When a ...
- 295
13
votes
2
answers
4k
views
Acidity of hydrogen chloride in acetic acid
A question asked to find the $\mathrm pK_\mathrm a$ of $\ce{HCl}$ in acetic acid. The equation of $\ce{HCl}$ disassociating in water is: $$\ce{HCl + CH3COOH \leftrightharpoons CH3COOH2+ + Cl-}$$ I ...
- 7,402
12
votes
5
answers
41k
views
How to determine the pH of a mixture of two weak acids?
We have two solutions:
Solution 1 is $\ce{HCOOH}$, its concentration is $c_1 = \pu{10^-2 mol/l}$, its volume is $V_1 = \pu{50 ml}$, and its $\mathrm{pH}_1 = 2.9$.
Solution 2 is $\ce{CH3COOH}$, its ...
- 121
12
votes
3
answers
109k
views
How do I calculate the degree of dissociation in equilibrium?
In my textbook, for calculating the percentage dissociation of $\ce{HF}$ for the given equation:
$$\ce{HF + H2O <=> H3O+ + F-}$$
The solution is:
Initial Concentrations
$$[\ce{HF}] = 0.08~\...
- 261
12
votes
2
answers
10k
views
How to calculate partition coefficients?
Below is a transcript of this doubtful question:
A weak monobasic organic acid $\ce{HA}$ is soluble in both water
and $\ce{CHCl3}$. $\pu{500.0 cm3}$ of a solution of $\ce{HA}$ in $\ce{CHCl3}$, ...
11
votes
1
answer
2k
views
Why are indicators used only in the form of dilute solutions?
Why are indicators used only in the form of dilute solutions? I get that indicators are a form of weak acids themselves, and the extent of their dissociation varies with the pH of the solution they ...
- 1,451
11
votes
1
answer
20k
views
Acid-base equilibrium of NH4CN
I'm having difficulties understanding this problem.
We have in the problem that $K_\mathrm a$ for $\ce{HCN} = 6.2\cdot10^{-10}$ and $K_\mathrm b$ for $\ce{NH3} = 1.8\cdot10^{-5}$.
Write chemical ...
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