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4 votes
1 answer
91 views

Derivation of Gibbs phase rule

I learnt about the Gibbs phase rule a while back but did not really think too much about how it was derived. I am now currently looking back at the derivation provided in the textbook and I realised ...
Tan Yong Boon's user avatar
2 votes
0 answers
78 views

Does copper(II) hydroxide dissolve in ammonia solution?

According to University of Oregon — Chemistry Interactive Demonstrations and Educational Resources — Copper-Ammonia Complex, the equilibrium constant for the formation of copper(II) hydroxide is ...
Shira's user avatar
  • 620
0 votes
0 answers
74 views

If a pocket of nitrogen gas is pumped in at the bottom intake of a padded tank will the pocket of gas bubble up?

I have a nitrogen gas padded tank (tank 1) which is filled from the bottom of the tank. Tank has a set point of 30 psi which adjusted as tank level changes. Also at the inlet is an additional pipe ...
Victor's user avatar
  • 19
3 votes
1 answer
113 views

Effect of Pressure on the Position of Equilibrium

The following general reaction proceeds with decrease in amount of substance, so increasing pressure should shift the position of equilibrium to the right. $$\ce{2 A(g) <=> B(g)}$$ But let's say ...
Muhammad Ali's user avatar
3 votes
1 answer
65 views

How can a Michaelis–Menten formalism be used when enzyme concentration isn't constant?

I understand that $V_\mathrm{max} = k_3[\ce{E}]_0$ in ordinary Michaelis–Menten (MM) kinetics. According to the lecture notes provided by my university (I don't believe they are available online), ...
user145205's user avatar
0 votes
0 answers
32 views

Understanding the relationship between Delta G and Kp, Kx and Kc

**Upon reading the chapter about equilibrium from my physical chemistry book, I was convinced that ΔG=−RTln(Kp)(1) and that Kp=Kx(P∑v)(2) where Kp is the equilibrium constant with respect to pressure ...
Kintoke 's user avatar
-1 votes
3 answers
107 views

How is it even possible that vapour pressure of liquid and vapour of solid are equal at freezing point? [duplicate]

My text book states The freezing point is defined as "the temperature at which the vapor pressure of the substance in its liquid phase is equal to its vapor pressure in the solid phase" Also ...
Aditya's user avatar
  • 35
-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, ...
Aurelius's user avatar
3 votes
0 answers
76 views

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, ...
Metal Storm's user avatar
  • 3,684
-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 ...
Dodo's user avatar
  • 288
-3 votes
3 answers
109 views

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 ...
Virender Bhardwaj's user avatar
2 votes
2 answers
147 views

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 $$ \left(\frac{\partial G}{\partial P}\right)_T = V \tag{2} $$ ...
Marijus Klp's user avatar
1 vote
1 answer
119 views

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 ...
Alfred's user avatar
  • 21
5 votes
1 answer
162 views

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 ...
Bongo Man's user avatar
  • 429
0 votes
1 answer
63 views

Reaction kinetics exercise for hydrogen iodide synthesis

The rate constant for the reaction of hydrogen with iodine is $\pu{2.45E-4 M-1 s-1}$ at 302 °C and $\pu{0.905 M-1 s-1}$ at 508 °C. a. calculate the activation energy and Arrhenius preexponential ...
wengen's user avatar
  • 423
-4 votes
1 answer
87 views

What happens to the ions after dissociation in an aqueous solution? [closed]

I'm in high school studying about Buffer Solutions. We had an example of a solution made up of Ammonium Hydroxide and Ammonium Chloride for a Basic Buffer. NH4OH ⇌ NH4 (+) + OH(-) NH4Cl ⇌ NH4 (+) + ...
Mel's user avatar
  • 1
1 vote
2 answers
184 views

How to obtain the expression for residual Gibbs energy?

The property involved is Gibbs free energy, the equations that I wrote are presented in my text book Introduction to chemical engineering thermodynamics by Smith and Van Ness, Chapter 6. The thing is ...
jack gatz's user avatar
0 votes
1 answer
70 views

Can an electrode run out of the active species?

I have a background in solid state physics but am new to electrochemistry. I have been following the example of a physical chemistry (Mortimer) book that looks an electrochemical cell with a hydrogen ...
Kyle's user avatar
  • 9
-3 votes
1 answer
241 views

If Qc> Kc how can forward reaction can take place

If Qc>Kc then there will be a net backward reaction but still forward reaction will take place. My problem is if Qc>Kc forward reaction will become non spontaneous right. So how can that happen, ...
Zayden's user avatar
  • 13
-3 votes
1 answer
131 views

What if kc=1 will reactants concentration equals to product concentration [closed]

I read a book, it says if kc=1 it mean reactant concentration equals to product concentration at equilibrium. But I'm wondering that in kc expression we dont just use concentration of an element we ...
Zayden's user avatar
  • 13
2 votes
3 answers
336 views

Change of equilibrium constant with respect to temperature

Suppose we have an arbitrary chemical reaction $A+B\rightleftharpoons 2C+D$ and its equilibrium constant at two temperatures $T_{1},T_{2}$ are $k_{1},k_{2}$. We can relate them as $$\log\frac{k_{2}}{...
Pravimish's user avatar
  • 169
0 votes
1 answer
84 views

Do complexes of a metal distribute in between the water and an organic compound layer?

My original question is one that is stated in the title, and I also have some side questions too. I came across this question where you have a CuSO4 aqueous solution. Then you take an Ammonia aqueous ...
donthababakka's user avatar
1 vote
0 answers
254 views

How to calculate pH of a 0.1 M solution of ammonium bicarbonate considering simultaneous equilibrium along with hydrolysis?

We need to calculate the $\ce{[H+]}$ of 0.1M $\ce{(NH4+)(HCO3^-)}$ given the $\ce{k_b(NH4OH), k_{a_1}(H2CO3), k_{a_2}(HCO3^-)}$ The hint tells me to directly use the result $\ce{[H+]=\sqrt{k_{a_1}(\...
Solus's user avatar
  • 35
4 votes
3 answers
1k views

What is the basis for the relationship of Gibbs energy and extent of reaction shown in this graph?

How this graph of Gibbs free energy between reaction coordinate is made because because ∆G = ∆G° + RT ln Q and since ∆G° and T is constant hence the graph should be like that of ln(x)? Source: https:/...
Garv Chaudha's user avatar
0 votes
4 answers
174 views

Which way Le Chatelier's principle

I have been pondering about the effect of pressure change in regard to Le Chatelier's principle on reactions. For this, I considered the following reaction: $$\ce{CO(g) + 3H2(g) <=> CH4(g) + H2O(...
Proscionexium's user avatar
0 votes
1 answer
120 views

Why change of gibbs energy per mole is zero at equilibrium?

I was reviewing this concept and thought of this: $\frac{dG}{dt} = \frac{\partial G}{\partial \xi}\frac{d \xi}{d t}$, for a reaction to be at equilibrium $\frac{d G}{d t}$ must be zero but I have ...
Julio César's user avatar
1 vote
0 answers
94 views

Unit of equilibrium constant in formula for Gibbs free energy change at arbitrary temperature

We know the relation for Gibbs free energy change of a reaction at any stage and any temperature $$\Delta G=\Delta G^{\circ}+RT\ln Q$$ where Q is reaction quotient. Subsequently, we get the rate ...
Pravimish's user avatar
  • 169
0 votes
0 answers
105 views

Confusion about equilibrium constant in simultaneous equilibrium

Ok, so the equilibrium constant in terms of pressure is the ratio of partial pressures at equilibrium of gaseous products to reactants (all raised to the powers equal to the stoichiometric ...
AVS's user avatar
  • 521
0 votes
3 answers
153 views

Doubt in heterogenous equilibria [closed]

Let us take the following equilibrium: $$\ce{NH4HS(s) <=> NH3(g) + H2S(g)}$$ I have been taught that since $\ce{NH4HS}$ is in the solid state, its concentration cant be taken and hence we write $...
Kshitij Kumar's user avatar
-1 votes
1 answer
373 views

Why do we take active mass of water 1 but while calculating pKa of water as 55.345? [duplicate]

First, I should mention that the question was already asked here:Why is active mass of a pure solid or liquid always taken as unity? But while calculating $\mathrm{p}K_\mathrm{a}$ of pure water we ...
mATHSloVER's user avatar
6 votes
2 answers
479 views

Equilibrium constant vs Reaction rate constant

For a reaction, e.g., $$a X + b Y → c Z$$ Its reaction rate constant is $${\displaystyle r=k_f(T)[\mathrm {X} ]^{m}[\mathrm {Y} ]^{n}}$$ where the exponents m and n are called partial orders of ...
ubuntu_noob's user avatar
1 vote
3 answers
199 views

Equilibrium constant for isothermal double equilibrium “shift”

I do not understand how the solutions to the following high school chemistry question are valid: A $\pu{1 L}$ vessel containing $\pu{0.300 mol}$ of dinitrogen tetraoxide gas is allowed to come to ...
John Hon's user avatar
  • 1,584
0 votes
0 answers
71 views

How to apply Le Chateliers' principle for the reaction between nitrogen and hydrogen to produce ammonia?

$\ce{N2 (g)}$ and $\ce{H2(g)}$ are allowed to react in closed vessel in given temperature and pressure for the formation of $\ce{NH3 (g)}$ according to, $$\ce{N2 (g) + 3H2 (g) <=> 2NH3 (g) + \pu{...
Rishi Shekher's user avatar
1 vote
2 answers
90 views

Find the percentage of dissociation of nitrogen tetroxide given pressure, temperature, enthalpy and entropy

Given $$ \begin{align} \Delta_\mathrm f H^\circ(\ce{N2O4}) &= \pu{9.16 kJ mol^-1} &\quad \Delta_\mathrm f H^\circ(\ce{NO2}) &= \pu{33.18 kJ mol^-1} \\ S^\circ(\ce{N2O4}) &= \pu{304.3 ...
Acedium 20's user avatar
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 ...
Acedium 20's user avatar
1 vote
1 answer
149 views

Can an equilibrium be reached when there is an excess amount of one reactant over the other reactant? [closed]

For example, consider a net reaction between ferrous nitrate and potassium thiocyanate: $$\ce{Fe^3+(aq) + SCN-(aq) <=> (SCN)^2+(aq)}$$ Can an equilibrium be reached if there is a much greater ...
JERry's user avatar
  • 81
1 vote
1 answer
80 views

What is the difference between a single displacement reaction and a two competing reaction system?

For example, consider the single-displacement reaction $$\ce{AB + C <=> BC + A}$$ My question is then if writing this reaction as the system \begin{gather} \ce{AB <=> A + B} \\ \ce{B + C &...
porphyrin3852's user avatar
8 votes
2 answers
514 views

Schlögl model - Stationary States far from Equilibrium

The Schlögl model can be represented as follows: $$ A + 2X \underset{k_2}{\stackrel{k_1}{\rightleftharpoons}} 3X \, , \\ X \underset{k_4}{\stackrel{k_3}{\rightleftharpoons}} B \, . $$ The chemical ...
RKerr's user avatar
  • 183
3 votes
1 answer
255 views

How does pressure affect the color of reaction medium with equimolar amounts or reactants and products at equilibrium?

Chlorine gas is pale yellow-green, and both hydrogen and hydrogen chloride are colorless gases. According to the Le Chatelier's principle, the change in pressure will not affect the following ...
nitsir's user avatar
  • 41
0 votes
1 answer
564 views

Degree of dissociation and conductance

My book says ratio of molar conductance at a given concentration of solute and molar concentration at infinite dilution is equal to degree of dissociation for weak electrolytes. I understand it ...
Gaurav's user avatar
  • 1
2 votes
1 answer
59 views

Rate law for thermolysis at temperatures well above the decomposition temperature

If the temperature is higher than the decomposition temperature, are thermal decomposition reactions reversible? For example, which of the following schemes would be more appropriate for temperatures ...
user898724's user avatar
0 votes
1 answer
58 views

Are there any well documented reactions with "persistent" intermediates

I'm a biology and/or math person, not a chemistry person. I have only taken the standard sequence of undergraduate courses up to organic chemistry, and that was some time ago, so please excuse (and ...
R. Burton's user avatar
  • 101
3 votes
1 answer
166 views

Why does the equation for chemical potential apply to liquids and aqueous solutes?

The equation for chemical potential of a gas can be derived as such: At constant temperature, $$\mathrm dG = V\,\mathrm dP \label{eqn:1}\tag{1}$$ Substituting with the ideal gas law $PV = nRT$, $$\...
Heat's user avatar
  • 360
0 votes
0 answers
29 views

Is there an agreement for a specific temperature referred to in the context of standard Gibbs energy? [duplicate]

I found an exercise in Physical Chemistry by Atkins et al, 8th edition, page 235 that I found confusing. The question is as follows. "7.2(b) Molecular bromine is 24 per cent dissociated at 1600 K ...
Galen N. P.'s user avatar
2 votes
1 answer
391 views

Electrode potential for saturated silver carbonate solution

An electrochemical cell is set up to measure the electrode potential $E(\ce{Ag^+}/\ce{Ag})$ using the saturated $\ce{Ag2CO3(aq)}$ solution $(K_\mathrm{sp}(\ce{Ag2CO3(aq)},\pu{25 °C}) = \pu{6.3E-12})$ ...
radastro's user avatar
0 votes
1 answer
400 views

Relation between Solubility Product and Equilibrium Constant

I had read about Solubility, and I found that Solubility is not Molarity (because previously I believe that both are same thing). But, they have a big difference (source : https://en.wikipedia.org/...
UJJWAL MISHRA's user avatar
0 votes
1 answer
906 views

Standard Gibbs free energy when all the reactants and products are at standard condition

I have read in my textbook that for a reaction $\Delta G=\Delta G^o-RT\ln Q $, where $\Delta G^o$ is the Gibbs free energy change when the initial concentration of products and reactants are unity. ...
Asher2211's user avatar
  • 159
1 vote
0 answers
108 views

Chemical equilibrium graph [closed]

How can we determine which reaction belongs to which graph. I mean in the above pic . We can observe two graphs and 2 equations. But there is no link between the two . Both the reactions proceed till ...
Integer's user avatar
  • 61
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 ...
user's user avatar
  • 23
-1 votes
2 answers
99 views

Mass of silver iodide that dissolves in ammonia [closed]

What mass of $\ce{AgI}$ will dissolve in $\pu{1.0 L}$ of $\pu{1.0 M}$ $\ce{NH3}?$ Neglect the change in concentration of $\ce{NH3}.$ Given: $K_\mathrm{sp}(\ce{AgI}) = \pu{1.5E-16};$ $K_\mathrm{f}(\ce{[...
G. Sai Rithvick's user avatar

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