All Questions
Tagged with equilibrium solutions
59
questions
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1
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Considering Le Chatelier's principle, what happens when you add more solute to a saturated solution already in equilibrium?
If I'm not wrong saturated solutions are in dynamic equilibrium. Will the addition of solute disturb the equilibrium? What exactly occurs and how to apply Le Chatelier's principle?
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votes
1
answer
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Find the pH of a solution obtained by mixing 100 ml 0.1m Na3PO4 and 100 ml 0.1 M NaH2PO4. Given that H3PO4: [Κα₁ = 10^-4, Κα₂ = 10^-7, Каз = 10^-11] [closed]
So, my query is that since NaH2PO4 is a weak acid, and Na3PO4 is a basic salt, wouldn't they react? Another theory was that since NaH2PO4 is a weak acid and Na3PO4 is a salt of strong acid and NaH2PO4,...
2
votes
4
answers
172
views
How can the Kw of water be constant?
I know in neutral solution, $\ce{[H+]}= \ce{[OH-]}= \pu{1.0 x 10^-7}$.
However, let’s say I add an acid like HCl. This will increase $\ce{[H+]}$, therefore it’s no longer $\pu{1.0 x 10^-7}$, but is ...
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1
vote
0
answers
42
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Why is it that in a buffer solution the equilibrium concentrations may be assumed to be the initial concentrations? [duplicate]
Considering the Henderson–Hasselbalch equation,
$$\text{pH} = \text{p}K_a + \lg \frac{[\ce{AcO⁻}]} {[\ce{AcOH}]}$$
$$\text{p}K_a = \lg \frac{[\ce{AcO⁻}][\ce{H⁺}]} {[\ce{AcOH}]}$$
Why are the values ...
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3
votes
2
answers
2k
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Calculate the titer of a solution
I hope this is the right place to ask. We have this exercise without solution
One litre of diluted sodium hydroxide solution (c = 0.15mol/litre) is
to be prepared in the laboratory. The titer from ...
- 423
1
vote
0
answers
69
views
Would a container made of sugar eventually dissolve if filled with a sugar-saturated solution of water?
Suppose you had a bottle made of sugar glass, and filled it with water that was already saturated with sugar.
I know that with a fully saturated solution of sugar in water, no additional sugar can ...
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1
vote
3
answers
994
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Why does equilibrium of ice and water only exist at 273K at normal pressure?
I am a high school student and I am a little confused in the concept of spontaneity of a reaction and how equilibrium works for a reaction, I got some confusions:
Let's take example of freezing of ...
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1
vote
1
answer
109
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Why does Raoult's Law have a weighted sum instead of a direct sum?
I'm fully aware of the various questions asked about Raoult's Law, and I'm asking this after having gone through all of them and not finding a suitable answer to my question.
I have studied, that at a ...
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4
votes
1
answer
159
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Why is the van ’t Hoff relation an approximation?
Lately, I've been looking and thinking about the fact that a professor told us in an advanced physiology lecture. When it came to mentioning osmotic pressure and the van ’t Hoff relationship
$$
\pi = ...
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votes
1
answer
34
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What is the ∆H_vap when temperature of a given liquid is equal to the boiling point of the liquid?
What is the $∆H_{vap}$ when temperature of a given liquid is equal to the boiling point of the liquid?
For the other cases ie (i) T>BP, $∆H_{vap}$ > 0 (ii) T<BP, $∆H_{vap}$ < 0
So what ...
0
votes
0
answers
66
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Osmotic Pressure of Aqueous Solution
The osmotic pressure of an aqueous solution at $25$ Celsius is $92.0$ $kPa$. Calculate the boiling point
of the solution. (Assume that the density of the solution is $1.0$ $g/mL$, ignore the mass of ...
- 117
0
votes
0
answers
126
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Why is the Ag+ concentration in a beaker fixed in the reaction between excess AgCl (s) and KI (aq) from the start? [duplicate]
This arises as a sub-question for the following question: Calculate the concentration of I- in a solution obtained by mixing 0.10 M KI with an excess of AgCl(s).
I tried to look at How does addition ...
0
votes
2
answers
2k
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How to know if a reaction forms H3O+ ions or OH- ions? [closed]
How would you know when an acid or base is paired with $\ce{H2O}$ that it will form an $\ce{OH-}$ ion or a $\ce{H3O+}$ ion? I just started the acid and base equilibrium unit, and I'm just confused on ...
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3
votes
0
answers
202
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What does isohydric solution mean?
While studying ionic equilibrium, I came across the term "Isohydric Solutions" which is defined as:
Solutions of electrolyte are said to be isohydric if the concentration of the common ion ...
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votes
1
answer
1k
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What is the difference between atom and nucleus? [closed]
Atomic nucleus-The atomic nucleus is the small dense region consisting of protons and neutrons at the center of an atom discovered in 1911 by EARNEST RUTHERFORD. Atoms are made up of a positively ...
0
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0
answers
138
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Problem in the calculation of ionic strength of a solution
Recently I've been trying to answer the question 10-13 (c) of 9th edition of Fundamentals of Analytical Chemistry of Skoog et al. Comparing my answers with the student manual , I realized that my ...
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4
votes
1
answer
8k
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How is the formula of mean activity coefficient derived?
The mean activity coefficient is defiend as follows:
$$\gamma_\pm = (\gamma_+\gamma_-)^{1/2}.\tag{1}$$
If Debye-Hückel equation
$$-\log\gamma_i = 0.5z_i^2\mu^{1/2}\tag{2}$$
is used, then the mean ...
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votes
4
answers
572
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How many grams of sodium phosphate must be added to precipitate as much of one ion as possible?
Problem text:
Solid sodium phosphate is slowly added to $\pu{200 mL}$ of a solution containing $\pu{0.002 mol}$ of aluminum chloride and $\pu{0.001 mol}$ of calcium chloride (assuming no volume ...
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1
vote
1
answer
557
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Vapour Pressure of A Solution
I study in class 12, and have a doubt in vapour pressure that my school teacher and my friends are not able to clarify.
My doubt is the reason why the partial vapour pressure of each individual ...
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1
vote
2
answers
393
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How can I calculate the amount of HF in aquoues solution of NH4F and an aquoues solution of NH4HF2?
Dissociation of $\ce{NH4F}$ and $\ce{NH4HF2}$ in water is complete, I assume:
$$\ce{NH4F -> NH4+ + F-}$$
and
$$\ce{NH4HF2 -> NH4+ + HF2-}$$
Can I calculate the amount of $\ce{HF}$ in these ...
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2
votes
2
answers
1k
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Will NaF + CaCO3 precipitate much CaF2?
If I mix sodium fluoride, calcium carbonate powder, and water, under what conditions (if any) would there be an equilibrium?
I.e. assume we start out with fully dissociated $\ce{Na+(aq) + F-(aq)}$, ...
6
votes
1
answer
731
views
If volatility depends on intermolecular forces, then why in Raoult's law, two substances have different volatility?
I have a doubt, Ideal solutions are solutions where intermolecular forces between solute-solute and solvent-solvent are nearly equal to solute-solvent. Since intermolecular forces between A-A = B-B, ...
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4
votes
3
answers
1k
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Dynamic equilibrium in unsaturated solutions
One standard definition of equilibrium in beginner chemistry is that for a reversible reaction, (dynamic) equilibrium has been achieved when the rate of the forward and backward reactions are equal. ...
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1
vote
1
answer
160
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Liquid solutions and vapour pressure
"The vapour pressure of water at 80° C is 355 torr. A 100 mL vessel contained water-saturated oxygen at 80° C, the total gas pressure being 760 torr. The contents of the vessel were pumped into a 50 ...
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2
votes
2
answers
2k
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Why doesn't the solute settle out of a solution, such as brine or sugar water? [closed]
If I have a solution of salt or sugar dissolved in water, the solute will never settle out or "fall to the bottom", no matter low long I wait. Why is that?
Since salt and sugar (in their pure, solid ...
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2
votes
1
answer
521
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Freezing point of solution
It's stated in my textbook that at the freezing point, the vapour pressure of the solid phase equals the vapour pressure of the liquid phase. In a mixture, since the vapour pressure of the solution is ...
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1
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Methyl Orange Indicator-Reason for small amount of NaOH [closed]
I used methyl orange as my indicator to titrate a weak acid:
At first, I added 3 drops of methyl orange to a solution of the weak acid, $\ce{CH3COOH}$, and the solution turned red. Then, after adding ...
0
votes
0
answers
35
views
How addition of a soluble salt affects equilibrium involving precipitation with a base sharing the same cation?
I have the following reaction at equilibrium:
$$\ce{Ba(NO3)2(aq) + KOH(aq) <=> Ba(OH)2(s) + 2 KNO3(aq)}$$
Will there be a change in the equilibrium if the salt $\ce{KCl}$ is added? Will the ...
-1
votes
1
answer
3k
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Calculate pH at equivalence point [closed]
Calculate the pH at the equivalence point of a titration of 62 mL of 0.1 M $\ce{CH_3NH_2}$ with 0.20 M HCl. The $\ce{K_b}=4.4\cdot10^{-4}$.
At the equivalence point, the moles of CH3NH2 equals the ...
4
votes
4
answers
4k
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Why does the degree of dissociation change when we dilute a weak acid even though the equilibrium constant is constant?
$K$ represents the ratio of concentrations of molecules in a solution at equilibrium, which means that $Q_\mathrm{r}$ (that ratio at any given point) looks to be identical to $K$. In other words, the ...
