All Questions
10
questions
1
vote
0
answers
36
views
Trends in pKb for both acetic acid and water
I am trying to rationalise a result that I have recently measured in the lab. I'm measuring the pKb of different compounds in anhydrous acetic acid, using the procedure outlined in this paper (https://...
- 11
-2
votes
3
answers
674
views
Can pure hydronium exist?
Can pure hydronium exist? If not, why not? It seems to me (and I am no chemistry expert) like pure hydronium should have the theoretical maximum acidity or minimum pH that a substance can reach.
Can't,...
2
votes
1
answer
271
views
pKa and pKb in solvents other than water
I know that when you have aqueous solutions, then the pKa and the pKb are linked to each other (pKa + pKb = 14). Is there an equivalent relationship between pKa and pKb in non aqueous environments? I'...
- 51
10
votes
4
answers
8k
views
What is the real pKa of water?
What is the $\text{p}K_\text{a}$ of water? A simple google search yields the value $15.74$, but this site and this paper say it's $14.0$.
According to my understanding, the correct answer should be $...
- 601
1
vote
1
answer
6k
views
How do I make a 0.5 M citrate buffer at pH 4.5?
I need to make a citrate-sodium citrate buffer at 0.5 M concentration and pH 4.5. I calculated the molarities of the citrate and disodium citrate based on the Henderson Hasselbalch equation, using a p�...
- 19
0
votes
1
answer
4k
views
Why would the pH of a solution not be 7 at the equivalence point of an acid-base titration? [duplicate]
Is it because the new substance formed might be acidic/basic ?
The internet defines this point as when the number of moles of the acid equals the number of moles of the base. But if we have for ...
- 333
1
vote
0
answers
114
views
Is it true that un-dissociated HCl exists in dilute hydrochloric acid?
My book says that the equilibrium constant for $\ce{HCl + H_2O}$ is so high that the reaction goes to completion. But that does not make sense since the existence of an equilibrium constant for this ...
- 333
-1
votes
1
answer
950
views
Why must NaOH be in excess if we wish to measure the effect acid strength has on the enthalpy of neutralisation?
A few different acids are given i.e $\ce{HCl}$ , ethanoic acid, $\ce{H2SO4}$, ethanedioic acid. We want to conduct an experiment in which we measure the temperature rise for neutralisation as a ...
- 485
8
votes
1
answer
1k
views
The open circuit voltage of a battery: Does it decrease with increase in pH of electrolyte while the voltage across a load increase?
Why does the open circuit voltage of a battery decrease with increase in $\mathrm{pH}$ of electrolyte, but the voltage across a load increase?
I tested a cell which had aluminum sulfate as its anode ...
- 864
3
votes
1
answer
499
views
How was the dissociation constant of water determined?
I was studying about pH and pOH of different acids and bases and I read about the dissociation constant of water ($\ce{H2O}$).
It turned out to be $1.00 \cdot 10^{-14}\ \mathrm{mol^2\cdot L^{-2}}$ ...
- 333