All Questions
Tagged with equilibrium aqueous-solution
128
questions
4
votes
2
answers
2k
views
Can I use the Henderson–Hasselbalch for calculating the pH of non-buffer systems?
Can I use the Henderson–Hasselbalch equation on reactions that are not buffers? When I read up on the derivation of the equation, I noticed that there is absolutely no assumption on the relative ...
1
vote
1
answer
14k
views
pH of CH3COOH + HCl solution (shouldn't be a buffer)
$\pu{0.05 L}$ of a solution containing $\pu{0.3 M}$ acetic acid $(\ce{CH3COOH}$, $K_\mathrm{a} = \pu{1.8e-5})$ are added to $\pu{75 mL}$ of a solution containing $\pu{0.02 M}$ hydrochloric acid ($\ce{...
- 19
1
vote
2
answers
411
views
Determining Kc for the equilibrium involving iron thiocyanate using spectrophotometric data
$$\ce{Fe^3+(aq) + SCN-(aq) <=> [Fe(SCN)]^2+(aq)}$$
$\pu{12.0 mL}$ of $\pu{0.00110 mol L-1}$ $\ce{Fe^3+}$ was added to $\pu{6.00 mL}$ of $\pu{0.00140 mol L-1}$ $\ce{SCN-}$. The absorbance of the ...
- 45
1
vote
1
answer
170
views
Should I include ions from the solvent in solubility product constant calculations?
I'm trying to determine the Solubility Constant $K_\mathrm{sp}$ of $\ce{Ba(NO3)2}$ dissolved in nitric acid solution $\ce{HNO3}$ from experimental data.
$\ce{HNO3}$ will be mostly dissociated so ...
- 199
4
votes
1
answer
906
views
How does monoethanolamine (MEA) increase pH?
I know pH of a solution increases with increase concentration of $\ce{OH-}$.
I'm wondering: when adding MEA, is the $\ce{OH-}$ group from the MEA breaking off, or is it the whole MEA molecule taking ...
- 41
1
vote
1
answer
6k
views
Equilibrium constant for the neutralization of weak acid by strong base
Acetic acid has a $K_\mathrm{a}$ of $\pu{1.8e-5}$. What is the equilibrium constant for the neutralization of this acid with $\ce{NaOH}$?
Given acetic acid
$$\ce{HC2H3O2 + H2O <=> C2H3O2- + ...
- 21
1
vote
2
answers
2k
views
Calculating solubility of iron(III) hydroxide in water
The following example in Skoog's Analytical Chemistry uses mass-balance and charge-balance equations to calculate the solubility of iron(III) hydroxide in aqueous solution.
$$
\begin{align}
\ce{Fe(...
- 811
-1
votes
1
answer
128
views
Acidity of carbonate ions creates paradox?
Whilst I understand why salts can be acidic or basic, the carbonate reaction confuses me (carbonate being a basic ion).
$$\mathrm{{CO_3}^{2-} + H_2O \ce{<=>} {HCO_3}^- + OH^-} \\
\mathrm{{...
- 1,584
2
votes
1
answer
1k
views
Why degree of dissociation/ionisation affected by dilution? [closed]
What happens when we dilute, say, an acid which is weak, and then add water to it? What motivates or pushes it to dissociate more?
We are just adding some molecules of water, right? So, what exactly ...
0
votes
1
answer
191
views
Equilibrium expression for dissolution of carbon dioxide
I was asked to give the equilibrium expression for:
$$\ce{CO2(aq) + H2O(l) <=> H2CO3(aq)}$$
As water is a liquid and a solvent here, it shouldn't be included in the expression, hence I wrote:
...
- 1,381
0
votes
1
answer
72
views
Calculating the change in pH upon diluting an acid
What volume of water is added to $\pu{400 ml}$ of $\ce{HCL}$ solution so that the pH of the solution increases by 1 unit
This is how far i went but the answer says $\pu{1000 ml }$ where am I wrong is ...
-1
votes
1
answer
149
views
Determine concentration of phosphate after copper(II) oxalate is precipitated
Solution with $\ce{Na3PO4}$ with $\pu{0.02 M}$ concentration and $\ce{Na2C2O4}$ with $\pu{0.03 M}$ concentration. I add excess $\ce{Cu(NO3)2}$ very carefully – tiny amounts.
What will be my $\ce{PO4^...
- 305
1
vote
2
answers
212
views
Weight of sodium acetate required to get to certain pH
How many grams of $\ce{CH3COONa}$ we need to dissolve in $\pu{2.50 L}$ of water to get a solution with $\mathrm{pH} = 9.00$? Given $K_\mathrm{a}(\ce{CH3COOH}) = 1.75\cdot 10^{-5}$
Like solving a ...
- 305
4
votes
1
answer
1k
views
Finding equilibrium constant from solubility product constant
Given
$$\ce{CuI(s) <=> Cu+(aq) + I-(aq)}\, ;\qquad K_\mathrm{sp} = 1.2 \cdot 10^{-12}$$
write a reasonable chemical reaction that describes the decomposition of $\ce{CuI2}$ in aqueous ...
- 1,381
4
votes
1
answer
169
views
A problem in solubility of salts with multistep hydrolysis of an ion possible
Calculate the solubility of $\ce{MnS}$ in pure water, $K_\mathrm{sp}(\ce{MnS}) = \pu{2.5e-10}$. Assume hydrolysis of $\ce{S^2-}$ ion. $K_1$ and $K_2$ for $\ce{H2S}$ are $10^{-7}$ and $10^{-14}$, ...
- 185