All Questions
Tagged with equilibrium ph
24
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
13
votes
1
answer
18k
views
Effect of Temperature on pH of Water
The $K_\mathrm w$ is a function of temperature. It is $10^{-14}$ at $25\ \mathrm{^\circ C}$. When the temperature is $50\ \mathrm{^\circ C}$, the $K_\mathrm w$ can be calculated to be somewhere around ...
- 435
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
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
4
votes
1
answer
1k
views
How do I quantify the carbonate system and its pH speciation?
I did Environmental Water Chemistry as part of my undergraduate course where we quantified pH-speciation for the full carbonate system and I got it right according to my tutor. My speciation profile ...
- 500
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.
$$
\begin{array}{lcc}
\text{Data for Alkali Metal ...
- 22.3k
7
votes
2
answers
7k
views
Combining acid dissociation constants to determine pH of diprotic acid
If I have a diprotic acid with $K_{\mathrm{a1}}$ and $K_{\mathrm{a2}}$ as the acid dissociation constants, why can't I calculate the final $\mathrm{pH}$ using $K = K_{\mathrm{a1}}\cdot K_{\mathrm{a2}}$...
- 235
6
votes
3
answers
28k
views
Calculation of the pH of a mixture of a strong acid and weak acid
The question is to find out the $\mathrm{pH}$ of a mixture of weak acid and strong acid. My book just states the formula as $$\mathrm{pH}=-\log
\frac{C_2+\sqrt{C_2^2+4K_\mathrm{a}C_1}}{2}$$
where $...
- 2,153
5
votes
2
answers
3k
views
Calculating approximate pH of polyprotic acids
When I took up ionic equilibria and titrations after a long break, I found it hard to solve the questions regarding pH calculations of polyprotic acds. Consider these two questions as examples:-
...
- 6,795
2
votes
5
answers
22k
views
Why does a buffer work best at the pH closest to its pKa?
I think I'm having trouble understanding exactly how the $\mathrm{p}K_\mathrm{a}$ relates here on a conceptual level. For example I know that carbonic acid works somewhat well as a buffer at $\mathrm{...
- 29
10
votes
5
answers
50k
views
What's the pH of vinegar containg 5% acetic acid?
Vinegar generally contains 5% acetic acid. We would expect the pH of vinegar to be approximately:
a. 0
b. 3
c. 7
d. 9
e. 12
I don't have the key for this question, so I just want to make ...
- 3,050
8
votes
2
answers
15k
views
Calculating pH of diprotic and amphoteric solutions
I am trying to understand this problem and its corresponding solution (complete solution not shown)
First off, from the above one can see that the equilibrium constants when $\ce{H2ASO4-}$ donates ...
- 3,256
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
2k
views
Calculating the pH of a ammonium hydrogen sulfate solution
I am attempting to complete a question in which I need to use an ICE table to calculate the pH of a $\pu{2.61 mol L-1}$ $\ce{NH4HSO4}$ (ammonium hydrogen sulfate) solution.
When $\ce{NH4HSO4}$ ...
