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Questions tagged [equilibrium]

The state in which both reactants and products are present at concentrations which have no further tendency to change with time.

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Calculation of pH of mixture of strong acid and strong base [on hold]

I have been given a mixture of 150 ml of an aqueous solution of HCl (pH = 2.0) and 350 ml of an aqueous solution of NaOH (pH = 12.0). How can I calculate the pH of of the mixture?
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24 views

Total pressure of mixture

I have the following problem: We put 200 mL of an equimolar mixture of pentane and hexane in a 900 mL container at a temperature of 20 °C. While the container is sealed, dry air at atmospheric ...
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Requesting basic explanation of concepts necessary to understand Ionic Equilibrium [on hold]

I request a basic and concise explanation of all the necessary concepts of the chapter chemical equilibrium (at the Indian highschool level) so that I would be ready to tackle the chapter Ionic ...
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0answers
15 views

Heterogeneous Chemical Equilibrium [on hold]

(Sorry if my english isn't that good). When heated a certain mass of $\ce{NH_4Cl}$ in a closed container, the following equilibrium is obtained: $$ \ce{NH_4Cl (s) ⇌ NH_3 (g) + HCl (g)} $$ If the ...
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0answers
22 views

Static equilibrium and open systems

Can a static equilibrium exist in an open system? For example Consider the reversible reaction between $\ce{H2O}$ (l) and $\ce{H2O}$ (g) in a water bottle (in dynamic equilibrium). However, if the ...
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0answers
36 views

pKa Conceptual Questions [closed]

If anyone could clear up some of this conceptual confusion, that would be much appreciated. Is $\mathrm pK_\mathrm a$ an intrinsic property of a molecule? Or extrinsic? A property is extrinsic if it ...
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15 views

Why is the pKa of protonated alcohol lower than that of a hydronium ion?

My lecture note say: Hydronium ion -> water has pKa -1.7 Protonated alcohol -> alcohol has pKa -2.4 Okay so that the two values are low makes sense, the equilbrium is quite far to the right and the ...
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11 views

Setup to prove dynamic nature of equilibrium [closed]

The basic question is how is it known that chemical equilibrium reached in reversible chemical reactions is dynamic and not static? What would be the experimental setup to demonstrate the dynamic ...
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Simultaneous exuilibrium , Ph Calculations and approximation [closed]

The Question is :- 200 ml of 0.1 M H3AsO4 (given Ka1 = $10^{-3}$ , Ka2 = $10^{-7}$ Ka3 = $10^{-12}$) 50 ml of 0.4 M Na2HAsO4, 50 ml of Na3AsO4 0.2 M solutions and 100 ml of 0.1 M HCL are mixed. Ph ...
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16 views

Vapour pressure [closed]

Does every pure liquid have same vapour pressure that is equal to 1atm at normal pressure temperature? If its right then how does this justifies vapour pressure of every liquid being dependent of its ...
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0answers
43 views

Is Gibb's Energy and equilibrium constant relation only applicable to gases

I have seen the Gibb's Energy and Equilibrium Constant relation $\Delta G=\Delta G^o+RT\ln Q$ (and many other thermodynamic equations) which seems to be applicable only to ideal gases. Using the ...
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2answers
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Does concentration or pKa define acid strength?

For example, is 3M HCl a stronger acid than 1M HCl? I would reason that the concentration of an acid/base does not influence its strength. Strength is determined by the pKa, and, as per Le Chatelier'...
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1answer
24 views

Effect of increasing product concentration on time of completion of reaction

This was the question asked in our chemistry exam: In the experiment of determination of equilibrium constant of esterification of ethanol, if , instead of using clean dry bottle, if a bottle already ...
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1answer
16 views

Why does a Lower Concentration of SO2 call for an increase of equipment dimensions in a Contact Process Plant?

I'm working on a presentation based on an article about the Contact Process (production of sulfuric acid), and it says that using a low concentration of SO2 at the entrance of the converter (in which ...
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0answers
24 views

Manganese (II) oxidation by air

I am studying the reaction of dissolved dioxygen with manganese(II) hydroxide for the Winkler method: 2Mn(OH)2(s)+O2(aq)⟶2MnO2(s)+2H2O(l) The ...
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0answers
9 views

Calculate the amount of ethylacetate produced after reached the equilibrium

1 mol acetic acid and 1 mol of ethanol was mixed to react to reach equilibrium. 0,75 mol of water was found in the product. a) calculate the Kc b) at the same temperature, 1 mol acetic acid, 1 mol ...
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1answer
83 views

Polyprotic acid - How does one calculate the CONCENTRATIONS of ALL species present in a solution when you start with 0.3M NaH2PO4? [duplicate]

Can anyone give me a push in the right direction, how do I calculate the concentration of all species present in a solution with 0.3M NaH2PO4. So the concentration of H3PO4, H2PO4 -, HPO4 2-, PO4 3- ...
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2answers
83 views

How to derive the relation between gibbs energy and equilibrium constant?

I want to understand the derivation between gibbs energy and equillibrium constant $$\Delta G=\Delta G^o+RT\ln Q?$$ I have seen a similar post on CSE Derivation of relationship between equilibrium ...
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2answers
35 views

Chemical Equilibrium in case of copper(II) ions [closed]

$\pu{Cu^{2+}}$ ions react with $\pu{Fe^{2+}}$ ions according to the following reaction: $$\ce{Cu^+2 + 2Fe^2+ <=> Cu + 2Fe^3+}$$ At equilibrium, the concentration of $\pu{Cu^{2+}}$ ions is ...
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0answers
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What change will occur for the following reaction if the hypochlorous acid solution is diluted from 0.1 to 0.01 M?

What change will occur for the following reaction if the hypochlorous acid solution is diluted from 0.1 to 0.01 M? $$\ce{HOCl(aq) + H2O <=> OCl-(aq) + H3O+ (aq)}$$ a.) a decrease in the ...
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1answer
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chemical equilibrium and exothermic reaction

here is an interesting question about the chemical equilibrium and Le Chatelier's principle. the following pressure show the partial that produced in the equilibrium reaction at time (t1 and t2) $$\...
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1answer
672 views

In a saturated solution, why is there ongoing dissolution and crystallisation?

I was studying equilibrium, and had this question.. In a saturated solution with sugar dissolved, why is there a constant process of dissolving and crystallising? What I mean by this is, why don't ...
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1answer
81 views

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH?

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH? The $K_a =1.8 × 10^{-5}$ for $\ce{CH_3CO_2H}$. Assume that the volumes of the solutions are ...
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1answer
41 views

Equation for the equilibrium constant for the hydration of carbonyls using UV spectroscopy

I was looking through the literature when I found this source: https://pubs.rsc.org/En/content/articlepdf/1967/tf/tf9676302131 Which states that the equilibrium constant Khyd is: Khyd = $\frac{[...
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3answers
44 views

molar solubility of CaF2 at pH3 given molar solubility at pH7 and pKa of HF

Here was my attempt #$1$ at a solution. $K_{sp}=[Ca^{2+}][F^-]^2$ Using the information at pH=7, I estimated that $K_{sp}\approx3.7\cdot10^{-11}$, which means that barely any HF formed. I assumed ...
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1answer
32 views

How can I find the equilibrium constant Kp without temperature?

The question I'm looking at is I found that that Kc = 139M^-1, but how can I determine Kp? There is no temperature given, but I was told that it is still possible to calculate.
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1answer
61 views

Calculating molar solubility of calcium hydroxide from solubility product

On the Wikipedia page for calcium hydroxide, the stated solubility product for $\ce{Ca(OH)2}$ is $K_\text{sp} = \pu{5.5 * 10^{-6} M^3}$. It doesn't stipulate the temperature, but I have a chemistry ...
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0answers
51 views

What is the solubility product for Calcium Hydroxide?

I've searched the web, and I can't seem to find an agreement for what the solubility product is for calcium hydroxide. My Chemistry book from 2007 says it is $\pu{5.5*10^{-6}M3}$ at $\pu{25 ^\circ ...
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1answer
25 views

How to correctly apply Law of mass action

While studying ionic equilibrium I came across a relation between solubility and solubility product for ternary salt. This is what was written in my book. Let the solubility of ternary salt $AB_2$ ...
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1answer
48 views

Solving chemical equilibrium equation by hand [closed]

I was trying to solve question 22 above. I obtained the equation: $$50=\dfrac{4\alpha^2}{(1-\alpha)(2-\alpha)}$$ Now, the resulting quadratic is too much of a pain to solve. How would one use ...
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32 views

Chemical equilibrium

In the Haber process, hydrogen and nitrogen are reacted to form ammonia. This reaction has a given equilibrium constant for the reaction at a given temperature. If we were to substitute hydrogen gas ...
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2answers
29 views

Is iron(III)nitrate changed and if so how?

We have the solution: $\ce{Fe^3+(aq) + SCN-(aq) <=>Fe(SCN)^2+}$ When we add more $\ce {SCN-}$ to the solution above, the solution produces more product. My question is, how does it affect $\...
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1answer
33 views

Why does a catalyst increase the forward and reverse reactions equally

With reference to the picture below, how is it that when there is a lower activation energy (due to the alternate reaction pathway provided by the catalyst) that the catalyst will increase the forward ...
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1answer
54 views

Why are solids and liquids ignored in the equilibrium constant?

If a reaction is taking place and is going towards equilibrium, wouldn’t the reactant be consumed to form products and vice versa? If this reactant/product is a solid or liquid, wouldn’t the number of ...
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1answer
35 views

How does Borax Solution act as a buffer? [closed]

What type of buffer is it? If it's a Weak Acid-Conjugate Base type of buffer, what is the weak acid and conjugate base?
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1answer
24 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: ...
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0answers
77 views

Color change of aqueous ferric salt when reacted with phosphate

I have a question about an equilibrium system: $$\ce{Fe^3+ (aq) + SCN-(aq) <=> [Fe(SCN)]^2+ (aq)}\\ \text{(yellow)} \quad \text{(colorless)}\quad \qquad\text{(red)}\qquad\quad$$ The question ...
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1answer
28 views

What is the meaning of K in the thermodynamic equation for equilibrium constant?

I just studied the formula for equilibrium constant in thermodynamics. But when an equilibrium is established $\Delta G$ is always $0$ as told by my teacher. Then $k$ has to be always $1$ whenever an ...
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1answer
163 views

How is silver chloride more soluble in brine than water?

I heard that: Silver chloride is more soluble in very concentrated NaCl solution (brine) than in pure water. Is it true? I mean won't the common ion effect operate? Or may be this is due to some ...
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0answers
45 views

Why are Txy diagrams curved for dew point and bubble point?

What is the reason behind drawing dew point curve and bubble point curve as curved (and dew point curved outwards and bubble point curved inwards) for Temperature vs Composition Phase Diagram as per ...
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1answer
24 views

Finding the error in attempting the equilibrium question through isotherm equations

Consider the partial decomposition of A as: $$\ce{2A(g) <=> 2B(g) + C(g)}$$ At equilibrium $\pu{700 ml}$ of gaseous mixture contains $\pu{100 ml}$ of gas C at $\pu{10 atm}$ and $\pu{...
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1answer
45 views

Why is the equilibrium constant unaffected by a change of the initial concentration?

In my class, it was taught that the equilibrium constant does not vary with the intial concentration of the reactants? Why is it so?
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2answers
63 views

Why is the concentration of protons equal to the concentration of a strong acid?

First, I know that strong acids are assumed to dissociate completely in water, so that the concentration of $\ce{H+}$ which they provide equals their concentration. What I am asking for is not the ...
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1answer
56 views

Buffer made of salts of polyprotic acid: reactions

I was trying to make a buffer with $\ce{K2HPO4}$ to use it in a bacterial culture. If I use $\ce{K2HPO4}$ I think I have to add $\ce{KH2PO4}$. I am trying to think it writing the equations of the ...
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3answers
217 views

Titration of Na2CO3 against HCl

$\pu{25mL}$ of $\pu{0.125M}$ $\ce{Na2CO3}$ is titrated with $\pu{0.100M}$ $\ce{HCl}$. Given that $K_{a1} = 4.3\times10^{-7}$ and $K_{a2} = 4.8\times10^{-11}$ for the diprotic acid $\ce{H2CO3}$, ...
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0answers
45 views

Difference between Henry constant and equilibrium constant

According to wikipedia, Henry constants define the ratio between the aqueous and gas fraction of a chemical species at equilibrium. Lets consider Henry constants H in atm.L.mol-1 such that $[C]_{g} = ...
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0answers
56 views

How to without calculations understand the liquid-liquid extraction efficiency?

I'm asking myself this question for a very long time and I haven't found a simple an good explanation yet for the fact that it's better (if you want to clean them) to wash your hands two times with ...
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1answer
40 views

Rate of a reaction [duplicate]

We know that the rate of a reaction $\ce{aA + bB -> cC + dD}$, the rate of the forward reaction is given by $r_\mathrm f = k_\mathrm f[\ce A]^p[\ce B]^q$ where $ a\neq p$ and $ b\neq q$ according ...
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49 views

Is the concentration of water included in the acid disscociation constant? - Wikipedia confuses me

I refer to the following wikipedia article https://en.wikipedia.org/wiki/Acid_dissociation_constant Header paragraph: Equilibrium constant. First the equilibrium constant is given in terms of ...
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1answer
62 views

Why don't buffer solutions return to equilibrium?

Suppose I want to make a buffer solution in any of the three ways possible with dihydrogen phosphate as my weak acid. In the first way, a certain ratio of the weak acid and its conjugate base are ...