All Questions
Tagged with equilibrium ph
139
questions
3
votes
3
answers
994
views
salt hydrolysis and pH calculations
I am a high school student and I am very confused in salt hydrolysis
My confusion is that: when we talk of hydrolysis of salt of weak base and weak acid, we internally assume the degree of hydrolysis ...
- 252
1
vote
1
answer
393
views
Why does the pH of a weak acid not increase by 1 when diluted by a factor of 10? [closed]
Strong acid pH increases by one unit when diluted by a factor of 10, but why do weak acids not?
- 23
2
votes
0
answers
48
views
A trick to find resultant pH [duplicate]
Consider the following problem:
Find the $\mathrm{pH}$ of the solution formed by the mixing of two solutions of $\mathrm{pH}$(s) $2$ and $3$ of equal volumes.
The normal way:
Since the resulting ...
- 397
-3
votes
1
answer
5k
views
pKa = pH for strong acid — strong base?
I have learnt that for a weak acid — strong base titration, $\mathrm{p}K_\mathrm{a} = \mathrm{pH}$ at the half equivalence point.
However, the same conclusion is not drawn when discussing strong acid —...
- 153
5
votes
1
answer
403
views
Common Ion Effect - Ionic Equilibrium
Question
In which of the aqueous solutions of the following, dissociation of $\ce{NH4OH}$ will be minimum?
A) $\ce{NaOH}$
B) $\ce{H2O}$
C) $\ce{NH4Cl}$
D) $\ce{NaCl}$
My Thoughts
My book says that ...
- 309
4
votes
3
answers
253
views
Is pK_{In} = pH at equivalence point still true for weak basic organic indicators?
I am reading Ostwald Theory of Titration which says that indicators are organic weak acids or bases.
To prove the relation that $\mathrm{p}K_\mathrm{In} = \mathrm{pH}$, the textbook uses the following ...
- 261
1
vote
0
answers
259
views
Calculating the pH of a sodium phosphate solution [closed]
I have the following question in a chemistry homework:
Calculate the $\mathrm{pH}$ of a solution made by dissolving $\pu{113 g}$ of sodium phosphate in enough water to make a solution with a final ...
- 21
-1
votes
1
answer
2k
views
How to calculate the amount of water required to increase the pH of a solution from 2.1 to 4? [closed]
After working out the problem with certain approximation of considering the initial pH=2, my answer came out to be around 1 litre of water. But the correct answer is 79 litres of water. Can anyone ...
- 11
0
votes
2
answers
431
views
pH of amphoteric species
For a solution of $\ce{HA-}$, I have seen the following approximations for the $\mathrm{pH}:$
$$\mathrm{pH} = \frac{1}{2}(\mathrm{p}K_\mathrm{a1} + \mathrm{p}K_\mathrm{a2})\tag{1}$$
$$\mathrm{pH} = \...
- 2,109
0
votes
3
answers
158
views
How to simplify these system of equilibrium equations
What is the pH when $0.025$ mol $\ce{NiCl2}$ is added to $\pu{1.00 L}$ of a $\pu{0.100 M}$ solution of $\ce{HCN}$, if the formation constant for $\ce{Ni(CN)4^2-}$ is $K_f=\pu{1.0e22}$, and the $K_a$ ...
- 2,109
3
votes
2
answers
1k
views
Use of Concentration for pH
When we find the pH of a solution, do we use normality or molarity? My teacher said that if the compound is present by itself, we can use normality but in all other cases we should use molarity. Can ...
- 31
3
votes
2
answers
821
views
Calculating pH of rain water
The concentration of $\ce{SO2}$ in the atmosphere over a city on a certain day is $\pu{10 ppm}$. Given that solubility of $\ce{SO2}$ in water is $\pu{1.3653 mol L-1}$ and $\mathrm{p}K_\mathrm{a}$ of $\...
- 224
1
vote
0
answers
79
views
How do I find pH of a mixture of weak acids? [duplicate]
Suppose that we are given two weak bases $\ce{HA_1}$ and $\ce{HA_2}$. We are also given the $K_\ce{HA_1}$ and $K_\ce{HA_2}$. How can we calculate the $\mathrm{pH}$ of the mixture?
- 144
-2
votes
2
answers
2k
views
pH of strong acid weak acid mixture [closed]
Question: $\ce{H2S}$ ($\pu{0.1M}$; $K_\mathrm{a} = 1.2×10^{-20} $) and $\ce{HCl}$ ($\pu{0.3M}$) with same volume are mixed together. What is the resultant $\mathrm{pH}$?
My approach:
Let the volume ...
- 117
2
votes
1
answer
3k
views
Calculating molecular weight of an acid based on given values of mass, volume, pH and pKa
This is what I thought was an easy problem but according to a given answer I am doing it wrong:
$\pu{11 mg}$ of a monoprotic acid was dissolved in $\pu{0.5 l}$ of water. The resulting $\mathrm{pH}$ ...
- 51