All Questions
50
questions
-2
votes
1
answer
49
views
Hydrolysis of $A_3B$ type weak acid-weak base salt
I know the formulae for weak acid-weak base salt of AB type. A peculiar question made me ask this. Do the formula for derived for AB type also hold for A3B type sal.
For example:
This is the question, ...
- 93
-1
votes
1
answer
130
views
Why is the ionic product of water also the equilibrium constant of dissociation of water?
This answer presents a derivation of the value of ionic product of water at $25^{\circ}\text{C}$.
The relation $K_\text{eq} = \operatorname{e}^{-\frac{\Delta_\text{r}G^{\circ}}{RT}}$ is used for the ...
- 288
3
votes
2
answers
144
views
What happens to the hydroxide ion concentration when you add caustic soda to ammonia?
Question.
Find the $[\ce{OH-}]$ and the pH of a $\pu{0.20 M}$ $\ce{NH3}$. If given $\pu{1 L}$ of the previous solution, when adding $\pu{100 mL}$ of $\pu{0.2 M}$ $\ce{NaOH}$, what would be the new ...
- 53
0
votes
1
answer
151
views
Problem understanding the rate of reaction of reversible reactions
Case 1:
$$\ce{CH_3COOH + NaOH<=>CH_3COONa + H_2O}$$
At equilibrium, there remain extremely small concentrations of the reactants (acetic acid and sodium hydroxide), and comparatively large ...
- 23
-3
votes
1
answer
78
views
Why do we need Equilibrium Constant as well as Acid Disocciation Constant? [closed]
I did the experiment to find out the dissociation constant of a weak acid using Henderson equation. However, after going through the theoretical part of the experiment, I am wondering why we need two ...
- 307
1
vote
1
answer
480
views
Acid dissociation constant calculated from the ionization percentage
The question goes like this:
An acid (HX) is 25% dissociated in water. If the equilibrium concentration of HX is $\pu{0.30 M}$, calculate the value of $K_\mathrm{a}$.
So I tried as follows:
if I ...
1
vote
1
answer
366
views
Calculating pH of aqueous ammonium hydrogen sulfide solution
I was doing the following question yesterday:
Calculate the pH of a $\pu{0.1 M}$ solution of $\ce{NH4HS}$, given $\mathrm{p}K_\mathrm{b}$ of $\ce{NH3}$ is $4.74$, and $\mathrm{p}K_\mathrm{a1}$ and $\...
- 1,411
5
votes
1
answer
2k
views
Does pressure affect pH? [closed]
Since pH is the function of $\ce{H+}$ ion concentration, the change in volume will change the equilibrium according to Le Chatelier's principle and affect the pH. Is it correct, or are there any ...
- 73
0
votes
0
answers
151
views
pH for an HA/NaA solution using a contour map
The following question has troubled me for a while now.
A virtual weak acid $\ce{HA}$ dissociates as follows:
$\ce{HA <=> H^+ + A^-}$
with the acid dissociation constant $K_\mathrm{a} = 10^{-3....
- 605
-1
votes
1
answer
1k
views
Equilibrium constant expression for an acid base reaction
While reading an organic chemistry textbook I saw the following Formula for calculating equilibrium constant of an acid-base reaction
Consider following acid base reaction in which $\ce{HA}$(reactant ...
- 194
2
votes
2
answers
427
views
Why is degree of dissociation used to estimate strength of an acid?
Problem
Which of the following will give strength of acid?
A) pH
B) Normality
C) Degree of dissociation
D) Dissociation constant
Answer
Question
If pH is not considered as a metric to assess the ...
- 1,409
0
votes
2
answers
344
views
Neutralisation of weak acid by base
I'm still working on my concepts related to chemical equilibrium. I came across this question:
10mL of a weak acid HA is 20%
dissociated in water. This solution is completely neutralised by 10 mL
of $...
- 149
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
1
vote
0
answers
141
views
What makes concentrated aqueous solutions of aluminium nitrate and aluminium chloride suitable to dissolve noble metals, specifically gold? [closed]
Aluminium nitrate is a strong oxidising agent and aluminium chloride acts as a Lewis acid. Also these solutions are claimed to have the abilities of aqua regia and therefore can dissolve noble metals.
...
- 11
-1
votes
1
answer
271
views
Does the acid dissociation constant takes hydrogen ions from water into account?
For the dissociation of a weak acid:
$$\ce{HA(aq)<=>H+ + A-}$$
To calculate $\mathrm{pH}$ of a weak acid, we use the expression: $$K_\mathrm{a}=\ce{\frac{[H+] [A-]}{HA}}$$
The $\ce{[H+]}$ has ...
- 500