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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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, ...
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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,...
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Can phosphorous penta hydroxide [P(OH)5] exist? [closed]
I was looking at the oxyacids of Phosphorous and it is given that (in Wikipedia article of "Phosphorous acid"), some of these acids (Eg: $H_3PO_2$ and $H_3PO_3$) exist in a dynamic ...
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Why does balancing the oxidation of dichromate(VI) to chromium(III) require six iron atoms?
The problem:
Balance the following chemical equation using oxidation numbers:
$$ \ce{Fe^2+ + Cr_2O_7^2- -> Fe^3+ + Cr^3+} $$
What I have tried:
$$\ce{\overset{+II}{Fe}^{2+}(aq) + \overset{+VI}{Cr}...
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Determine equilibrium stability transition of a reaction (function of temp and concentrations)
I am trying to calculate and plot the stability of $\ce{Fe3O4 - FeS2}$ based on the chemical equation:
$$ \ce{Fe3O4(s) + 6SO2(g) + 16CO(g) -> 3FeS2 (s) + 16CO2(g)} \tag{1} $$
I want to plot the ...
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Really though, why can't a equilibrium manifest in a open system?
What my teacher said today: "Equilibrium is not attainable in an open system because then there the concentrations of the species in the system are undergoing continuous change, thus the reverse ...
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My textbook writes hydronium ion as [H(H2O)]+, is this correct? [closed]
[...] Thus, it bonds to the oxygen atom of a solvent water
molecule to give trigonal pyramidal hydronium ion, $\ce{H3O^+}$ $\ce{\{[H (H2O)]^+\}}$ (see box).
In this chapter we shall use $\ce{H^+(aq)}$ ...
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Why doesn't sodium bicarbonate dissolved in water spontaneously effervesce when carbonic acid does?
It's well known that if you put carbonic acid $\ce{H2CO3}$ into water it will dehydrate into carbon dioxide $\ce{CO2}$ and water $\ce{H2O}$. Indeed this is how modern fizzy drinks generate their fizz. ...
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Bodenstein Hydrogen Iodide equilibirum experiment query
This text says that the same amount of HI was formed during the bulbs' time spent in the thermostat baths, regardless of the varying initial amount of HI each bulb contained.
Is this true? I always ...
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Why does balancing the reduction of dichromate(VI) to chromium(III) require four water molecules among the products?
Problem
Balance the following chemical equation using oxidation numbers:
$$\ce{Cr2O7^2–(aq) + HNO2(aq) –> Cr^3+(aq) + NO3–(aq)}$$
Solution (in Swedish)
$$\ce{\overset{+VI}{Cr}_2O7^2–(aq) + H\...
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Isoelectric Point
How do we derive the formula of isoelectric point?
pI=(pKa1 + pKa2)/2
I read that isoelectric point is defined as the pH at which degree of protonation in amino group is same as degree of ...
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Bancroft's point
In the last problem (Problem 10.43) within the problem section of Chapter 10 in "Introduction to Chemical Engineering Thermodynamics" (J.M. Smith, H.C. Van Ness, M.M. Abbott, McGraw-Hill, ...
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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 ...
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Inconsistency in between Nernst Equation and Gibbs Free Energy Equation [closed]
Part 1 - Derivation of the Gibbs Free Energy Equation: [copied from this]
Using the fundamental equations for the state function (and its natural variables):
\begin{align}
\mathrm{d}G &= -S\...
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How salt helps to melt ice even when there is no dynamic equilibrium between water and ice?
I am a high school student and I am confused about freezing point depression.
We say that when in winter's it gets even colder than normal freezing point Temperature then we use solute to melt ice ...
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Why are buffer solutions not neutral
I am very confused about buffer solutions and I have lots of ideas about them which don’t integrate together so I really can’t tell which are correct and which are wrong. That being the case it’s ...
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Unattainable equilibrium
I read a question on a textbook that asked:
For the reaction
$$ \ce{CaCO3(s) \rightleftharpoons CaO(s) + CO2(g)} \tag{1}$$
determine whether or not a mixture of $\ce{CaCO3(s)}$ and $\ce{CO2(g)}$
at a ...
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Temperature dependence on the feasibility of an equilibrium
If we consider a reaction A + B ⟶ C + D, with $\Delta$S $>0$, then regardless of whether $\Delta$H is positive or negative, increasing the temperature will make $\Delta$H - T$\Delta$S more negative,...
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Multiple equilibria
I was reading about multiple equilibria reactions and can't quite comprehend some things.
Suppose we have two reactions:
\begin{align}
\ce{A + B &<=> C + D},& K_\mathrm{eq} &= 10^{20}...
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Derivation of general binding equation (macromolecule with multiple binding sites)
So the last days I'm stuck at trying to solve the an equation - but I just can't (see the screenshot below.
So the idea is that you have a receptor or enzyme with multiple binding sites for a Ligand (...
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Boiling point, pressure, and Gibbs free energy
The water boiling process can be represented by the equation:
$$ \ce{H2O(l) → H2O(g)} \tag{1} $$
Since free energy depends on pressure
$$ \left(\frac{\partial G}{\partial P}\right)_T = V \tag{2} $$
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Van't Hoff graph, the Ka is increasing at a slower rate as temperature increases
I understand the exponential relationship between Ka and temperature, but I had expected it to be curving upwards(because of the $e^x$), and not like a log graph (where y-values increases slower for ...
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Does Hess' law in standard conditions involve consuming all reactants?
The standard free energy change for equilibrium problems is relative to both reactants AND products starting at 1 molar.
Hess’s law takes the sum of the values for products minus the sum of the values ...
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How to convert the uncertainty of my pH probe to the uncertainty of my Ka value
Literally the title. So basically I performed numerous titrations with ethanoic acid sodium hydroxide. I got the full pH curve, and subsequently found the Ka Value of the ethanoic acid. Now here is ...
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Are catalysts considered when assigning type of chemical equilibrium?
So I have very short doubt that whether catalysts are considered when we say that an equilibrium is homogeneous or heterogenous, like in an aqueous equilibrium with only aqueous reactants and products ...
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Van't Hoff Equation isolating for K2
So I wanted to find the theoretical Ka values of acetic acid from 25-65 degrees at 10 degree increments: 25, 35, 45, 55, 65.
I know that the dissociation of acetic acid is endothermic, and when I ...
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Why does a small decrease in [ATP] cause a large increase in [AMP]
I was wondering how the reaction catalysed by adenylate kinase and its equilibrium of approximately 1 leads to [AMP] changing greatly with a small change in [ATP]. The below information was provided ...
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Calculating partial pressure: Difficult cubic equation in bulky Chemical Equilibrium numerical
The problem, which I found in a popular book for Physical Chemistry, written by Neeraj Kumar, is fairly simple, being simply 2 equations and 2 variables, yet its simplification is a nightmare.
$\pu{5 ...
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Evaluating the density of a gas equilibrium mixture
I'm a beginner in chemistry (first year uni course) and I have this exercise that I need some help with. I don't really know where to start so for now. I've tried random approaches to see what works ...
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Are buffer solution and acidic buffer different? [closed]
I have studied that acidic buffer is a type of buffer solution but the definition of buffer solution says that it's a mixture of a weak acid and its conjugate base or a weak base and its conjugate ...
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