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Are phenyl and allyl groups in phenylpropene coplanar? |
Wouldn't C1 and C2 in prop-2-enylbenzene be on the same plane as that of the phenyl ring, right? If the double bond connected to C2 was between it and C1, they would be, but is it correct that now they're both planar, but on different planes?
[![prop-2-enylbenzene][1]][1]
[1]: https://i.stack.imgur.com/ZMxTW.... |
Are phenyl and allyl groups in prop-2-enylbenzene coplanar? |
> For the oxidation of iron,
>
> $$\ce{4 Fe(s) + 3 H2O(g) -> 2 Fe2O3(s) + 3 H2(g)}$$
>
> the entropy change is $ \pu{–549.4 J K^{-1} mol^{-1}}$ at $\pu{298 K}.$ In spite of the negative entropy change of this reaction, why is the reaction spontaneous? $(\Delta_\mathrm{r}H^\circ$ for this reaction is $\pu{–1648 k... |
The initial state of your system consists of 4 moles of $\ce{Fe(s)}$ and 3 moles of water vapor at $\pu{298 K}$ and $\ce{1 bar}$ in separate containers. The final state of your system consists of 2 moles of $\ce{Fe2O3(s)}$ and 3 moles of $\ce{H2(g)}$ at $\pu{298 K}$ and $\pu{1 bar}$ in separate containers.
The $\Del... |
Why can sulphate concentration increase after 3 days in a finished product of phenol sulfonic acid? Phenol and sulphuric acid are mixed at 95-98 C, while phenol concentration is stable. |
**Probably not**
Part of the problem with the question is geometry. Any two points always form a plane. What I suspect you mean is "is the allyl double bond in the same plane as the benzene ring?" in which case the answer is probably not.
To make the situation clearer here is a different numbering of the atoms in... |
I am modelling $\ce{H2O2}$ decomposition in Chemkin Pro and I have difficulty finding $\pu{C_p}$ (Specific heat at constant pressure) for liquid $\ce{H2O2}$ for various temperature ranges.
My ultimate aim is to find the 14 NASA polynomial coefficients so that I can input them in Chemkin Pro. For that I need a range... |
Beta sheets are illustrated as such in most diagrams, where:
1. In an antiparallel β-sheet, the polypeptide strands are arranged such that a $\ce{C=O}$ and an $\ce{NH}$ from adjacent strands face each oth... |
48gms of graphite and 16gmd of $O_2$ is given. The question is to count the no of molecules of $CO_2$ produced ?
Now , the solution in book is this
No of C atoms = 48gm/12gm = 4mole. No of O atoms = 16/16 = 1 mole , and no of O2 atoms = 0.5 mole.
The reaction given is
C + 2O gives $CO_2$ .
CO2 produced is 1/2 mo... |
> Why are hydrogen bonds in an antiparallel beta sheet stronger than those in parallel beta sheets?
They are probably not. The difference is small, and depends on sequence context. Also, the diagrams do not reflect the typical conformation of the backbone in beta sheets. To complicate matters, most sheets are mixed ... |
I have a bathtub that I accidentally poured wood stain into. Now the stain is all over the white ceramic surface of the tub. I tried using bleach but it didn't do anything. I'm curious if there is a chemist who would know the answer.
This is the wood stain I used:
https://www.menards.com/main/paint/interior-paint-s... |
> **OP’s question 1:** Where did I go wrong with that?
OP’s only mistake on the calculation here is the assumption of alcohol and water are additive. However, as matt_black pointed out in his answer that alcohol and water are not additive since the smaller water molecules can take up some of the space between the l... |
I have a bathtub that I accidentally poured wood stain into. Now the stain is all over the white ceramic surface of the tub. I tried using bleach but it didn't do anything. I'm curious if there is a chemist who would know the answer.
I used [Varathane® Premium Fast Dry Interior Oil-Base Cabernet Wood Stain](https://... |
I am modelling $\ce{H2O2}$ decomposition in ANSYS Chemkin-Pro and I have difficulty finding $C_p$ (specific heat at constant pressure) for liquid $\ce{H2O2}$ for various temperature ranges.
My ultimate aim is to find the 14 NASA polynomial coefficients so that I can input them in Chemkin-Pro. For that I need a rang... |
The follow molecule has a stereocenter?
[![enter image description here][1]][1]
I entered the name of the molecule in red and green lecters
I knew that we have a stereocenter if the carbon is bonded to four different groups.
According to the stereocenter rules, i should have Ch2 bonded to the carbon of the stereo... |
Is a stereocenter molecule in the image? |
I knew that we have a stereocenter if the carbon is bonded to four different groups.
According to the stereocenter rules, I should have $\ce{CH2}$ bonded to the carbon of the stereocenter (marked with asterisk), an ethyl and a hydrogen. How is it possible to have two equal groups? What did I do wrong?
[![3‐ethyl‐... |
Does 3‐ethyl‐1,1‐dimethylcyclohexane have a stereocenter? |
Electron affinity of atoms in the same row usually increases with the atomic number until the shell or half-shell gets full, and then it drops down. Some transition metals are exceptions from the rule, but the strangest exception to me is Titanium: while scandium ($3d^1$) has an affinity of 18 kJ/mol, titanium ($3d^2$)... |
I'm having difficulty understanding why the base-centered orthorhombic crystal system is a unique crystal system. When I draw two base-centered orthorhombic unit cells next to each other there appears to be a primitive crystal that is contained within the union of the two lattices as shown in the image below.
[![Bas... |
Why is the base-centered orthorhombic crystal lattice a unique crystal system? |
I'm having a hard time understanding what equivalent weight means physically. I've looked at many articles on Google but the definition always seems nebulous to me.
For example, if the equivalent of H2SO4 is 49 g/mol, what exactly does that mean? |
From the chemical structure of acac- compared to NH3 and en, is acac- a stronger or weaker ligand strength? How and why do we know this? |
Is acac- a weak field ligand? |
$\pu{48gms}$ of graphite and $\pu{16gms}$ of $\ce{O2}$ is given. The question is to count the no of molecules of $\ce{CO2}$ produced ?
Now , the solution in book is this
No of $\ce{C}$ atoms = $\frac{\pu{48gm}}{\pu{12gm}}$ = $\pu{4mol}$. No of $\ce{O}$ atoms = $\frac{16}{16}$ =$\pu{1 mol}$ , and no of $\ce{O2}$ a... |
$\pu{48g}$ of graphite and $\pu{16g}$ of $\ce{O2}$ is given. The question is to count the no of molecules of $\ce{CO2}$ produced?
Now, the solution in book is this
No of $\ce{C}$ atoms = $\frac{\pu{48g}}{\pu{12g}}$ = $\pu{4mol}$. No of $\ce{O}$ atoms = $\frac{16}{16}$ =$\pu{1 mol}$ , and no of $\ce{O2}$ atoms = $... |
Recently my teacher finished teaching the chapter Chemical kinetics in which I have gone through Arrhenius equation.Can we estimate the change in entropy using it? I have done my calculation, considering the reversible reaction, $\ce{A <=> B}$ which has forward and backward rate constants $\mathrm{k_f}$ and $\mathrm{k_... |
I have some water-soluble crystalbond that is attached to silicon and, because of some overheating (to about 150 Celcius) during a final processing step, the crystalbond seems to have charred (white/grayish colour) and is no longer dissolvable in water. Since this silicon is important and not replaceable, I really need... |
Removing denatured Crystalbond? |
I have some water-soluble crystalbond that is attached to silicon and, because of some overheating (to about 150 Celcius) during a final processing step, the crystalbond seems to have charred (white/grayish colour) and is no longer dissolvable in water. Since this silicon is important and not replaceable, I really need... |
I'm having a hard time understanding what equivalent weight means physically. I've looked at many articles on Google but the definition always seems nebulous to me.
For example, if the equivalent of $\ce{H2SO4}$ is $\pu{49 g/mol}$, what exactly does that mean? |
The iterative method I have learned to make flash calculations for a binary system where I know the inlet feed (F [mol/s]), total composition of the two components ($z_1$ and $z_2$), the amount of the mixture which is evaporated (q) and the total pressure (P [mmHg]) is as follows:
1. We seek T, $x_i$ (composition of... |
An interpation of the implicit derivative by the marginal rate of substiution makes this clear
>Marginal rate of substitution
In economics, when the level set R(x, y) = 0 is an indifference curve for the quantities x and y consumed of two goods, the absolute value of the implicit derivative
dy
/
dx
is interpr... |
[Wikipedia](https://en.wikipedia.org/wiki/Calcium_peroxide) states that the industrial preparation of calcium peroxide is done with calcium hydroxide, not the acetate or a neutral salt. Compare this choice with those used commercially for [magnesium peroxide](https://en.wikipedia.org/w/index.php?title=Magnesium_peroxi... |
My first question has to do with the fact that **Hydroboration produces an anti-markovnikov product, why?**. I don't see how that happens. A wikipedia artical says that B has a partial positive charge because it reacts slightly faster than H to form the bond but how is that possible when both H and C are more electrone... |
I observed a sharp decrease in the current when I carried out the electrolysis of water. Just to set the context, I used a voltage of 12V and the concentration of my electrolytes were 0.1 mol dm-3 for Ca(NO3)2 and I used graphite rods which were flaking but I am not sure whether that might cause such a significant dip ... |
This is an example of a Schott bottle:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/pJh4O.jpg
Using the volume markings would not be very accurate, so you would weigh the water.
Citric acid solution is indeed less dense than you would calculate from the volumes and densities of... |
I attempted to prepare saturated citric acid solution from anhydrous powder. According to online data, the solubility limit was 59.2 w/w at 20 °C, i.e. 59.2 g citric acid in 100 mL water. To ensure full saturation (as in the case of preparing brine solution), I ended up weighing 67 g of the powder and tried adding 100 ... |
> **OP’s question 1:** Where did I go wrong with that?
OP’s only mistake on the calculation here is the assumption of alcohol and water are additive. However, as matt_black pointed out in his answer that alcohol and water are not additive since the smaller water molecules can take up some of the space between the l... |
> **OP’s question 1:** Where did I go wrong with that?
OP’s only mistake on the calculation here is the assumption of alcohol and water are additive. However, as matt_black pointed out in his answer that alcohol and water are not additive since the smaller water molecules can take up some of the space between the l... |
I observed a sharp decrease in the current when I carried out the electrolysis of water. Just to set the context, I used a voltage of $\pu{12V}$ and the concentration of my electrolytes were $\pu{0.1 mol dm^{-3}}$ for $\ce{Ca(NO3)2}$ and I used graphite rods which were flaking but I am not sure whether that might cause... |
I observed a sharp decrease in the current when I carried out the electrolysis of water. Just to set the context, I used a voltage of $\pu{12V}$ and the concentration of my electrolytes were $\pu{0.15 mol dm^{-3}}$ for $\ce{Ca(NO3)2}$ and I used graphite rods which were flaking but I am not sure whether that might caus... |
I am working through some MIT lecture notes trying to understand adiabatic flame temperature. There is a section in these notes where $K_p$ is calculated for the following reaction at 1600K.
$CO + \frac{1}{2}O_2 \rightleftharpoons CO_2$
The notes find $K_p$ by using the following values:
$@1600K:$
$\log K_p... |
I observed a sharp decrease in the current when I carried out the electrolysis of water. Just to set the context, I used a voltage of $\pu{12V}$ and the concentration of my electrolytes were $\pu{0.15 mol dm^{-3}}$ for $\ce{Ca(NO3)2}$ and I used graphite rods which were flaking but I am not sure whether that might caus... |
After investigating what makes the persistent radical TEMPO stable, I was wondering if another compound which is more feasible for my needs would be comparable to it.
Would oxidizing 2,2’-Dimethyl-Diphenylamine result in a compound similar to TEMPO? It will have an Aminoxyl group and have the steric hindrance of the m... |
iupac name please? |
I am working through some MIT lecture notes trying to understand adiabatic flame temperature. There is a section in these notes where $K_p$ is calculated for the following reaction at $\pu{1600K}$.
$$\ce{CO + \frac{1}{2}O_2 \rightleftharpoons CO_2}$$
The notes find $K_p$ by using the following values:
@$\pu{16... |
I am working through some MIT lecture notes trying to understand adiabatic flame temperature. There is a section in these notes where $K_p$ is calculated for the following reaction at $\pu{1600K}$.
$$\ce{CO + \frac{1}{2}O_2 \rightleftharpoons CO_2}$$
The notes find $K_p$ by using the following values:
@$\pu{16... |
After investigating what makes the persistent radical TEMPO stable, I was wondering if another compound which is more feasible for my needs would be comparable to it.
Would oxidizing 2,2’-Dimethyl-Diphenylamine result in a compound similar to TEMPO? It will have an Aminoxyl group and have the steric hindrance of the m... |
My IB Chemistry class needs to have our Internal Assessment ideas finalized by next week, and I'm torn between a few experiments. I'm considering performing an oxidation of ethanol and potentially using colorimetry to measure the rate of the reaction (I believe using sodium dichromate as the oxidizing agent will create... |
Is it feasible to calculate the rate law of the oxidation of ethanol using colorimetry? |
I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese IV oxide catalyst at 5 different temperatures. Is there any way that I can find concentrations to then find the rate constant, k, and make an Arrhenius graph to find activation energy? Any help would be much appr... |
Is $18:82$ a valid ratio for Aqua Regia/(s)(nitrohydrochloric acid)? Source below |
I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese IV oxide catalyst at 5 different temperatures:
$$\ce{2 H2O2 (l) ->[MnO2 (s)] O2 (g) + 2 H2O (l)}$$
Is there any way that I can find concentrations to then find the rate constant, k, and make an Arrhenius g... |
I've read some answers online but I still can't seem to understand the mirror image effect. Why is the highest energy absorption (v" = 0 to v' = 4) the lowest energy fluorescence (v' = 4 to v" = 0)? Shouldn't the molecule that absorbs the highest-energy light emit the highest-energy light?
[![enter image description... |
Why is there a mirror image effect in the absorbance and fluorescence spectra? |
I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese(IV) oxide catalyst at 5 different temperatures:
$$\ce{2 H2O2 (l) ->[MnO2 (s)] O2 (g) + 2 H2O (l)}$$
Is there any way that I can find concentrations and then find the rate constant, $k$? And, using them, ma... |
High school chemistry student here. Currently, we are learning stoichiometry and I noticed that when we calculate the limiting reactant of a reaction with multiple products, we almost always just take into account the first product. One sample of this can be found at chem.libretext
[![enter image description here][1... |
Why do we only take into account the first product while calculating a limiting reactant? |
Is 18:82 a valid ratio for Aqua Regia/(s)(nitrohydrochloric acid)? Source below |
Is 18:82 a valid ratio for aqua regia? |
I am studying statistical mechanics and force-fields, and I see a lot of this formula being thrown around with no explanation:
$$U_{\mathrm{dihedral}} = \begin{cases}
k(1+\cos (n\psi + \phi)),& n>0 \\
k(\psi - \phi)^2, & n=0 \\
\end{cases} $$
The only explanation I read is: this is a 4-body torsi... |
Can someone help me understand the motivation behind and visualize the dihedral potential and the Urey-Bradley potential? |
Seeing Copper has an exceptional electron filling in its valence shell(4s1 3d10), the way I see it is that on +1, a d10 configuration should be more stable and hence easier to attain than a d9 which would come on +2. Or is there some reorganisation of electrons? Either way, please help explain. Thank you. |
Why is Cu(II) more stable than Cu(I)? |
Is there any Pythonic way (a.k.a: a module, an rdkit package, etc) or an API I can use for ADME predictions? I need to prioritize some compounds for purchase/synthesis and some sort of ADME scoring might help me rule out most of them.
I am aware of tools like [SwissADME](https://www.nature.com/articles/srep42717) b... |
Are there any ADME predictions tools available for Python/RDKit? |
After investigating what makes the persistent radical TEMPO stable, I was wondering if another compound which is more feasible for my needs would be comparable to it.
Would oxidizing 2,2’-dimethyl-diphenylamine result in a compound similar to TEMPO? It will have an Aminoxyl group and have the steric hindrance of the... |
The $K_p$'s here are those for the standard formation reactions.
If you go to the following link, you will see $\Delta G^o_f$ values for $\ce{CO2(g)}$ and $\ce{CO(g)}$ at $100 \,\text{K}$ increments up to $1500 \,\text{K}$:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjbt56Z9IbvAhXVj... |
The $K_p$'s here are those for the standard formation reactions.
If you go to the following link, you will see $\Delta G^o_f$ values for $\ce{CO2(g)}$ and $\ce{CO(g)}$, in $100 \,\mathrm{K}$ increments, up to $1500 \,\mathrm{K}$:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjbt56Z9Ib... |
The $K_p$'s here are those for the standard formation reactions.
If you go to the following link, you will see $\Delta G^o_f$ values for $\ce{CO2(g)}$ and $\ce{CO(g)}$, in $100 \,\mathrm{K}$ increments, up to $1500 \,\mathrm{K}$:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjbt56Z9Ib... |
Wikipedia's [Liquid Oxygen](https://en.wikipedia.org/wiki/Liquid_oxygen) says:
>The tetraoxygen molecule ($\ce{O4}$) was first predicted in 1924 by Gilbert N. Lewis, who proposed it to explain why liquid oxygen defied [Curie's law](https://en.wikipedia.org/wiki/Curie%27s_law). Modern computer simulations indicate th... |
Did O₄ turn out to explain why liquid oxygen appeared to defy Curie's law? If not, what does? |
I am quite a beginner in DFT and I am studying the theory behind the computational tools. I have some doubts about the Columb approximate functional term:
$U[n] = \frac{1}{2} \int d^3 r \int d^3 r^\prime \frac {n(\mathbf{r}) n(\mathbf{r}^\prime)}{|\mathbf{r} -\mathbf{r}^\prime|}$
If I use the definition of the elect... |
I am quite a beginner in DFT and I am studying the theory behind the computational tools. I have some doubts about the Columb approximate functional term:
$U[n] = \frac{1}{2} \int d^3 r \int d^3 r^\prime \frac {n(\mathbf{r}) n(\mathbf{r}^\prime)}{|\mathbf{r} -\mathbf{r}^\prime|}$
If I use the definition of the elect... |
"How to verify that ethanol is infinitely soluble in water?".
You cannot do it because it is WRONG. And not because it is false for ethanol, it is simply plain wrong conceptually and mathematically.
Solubility is the ratio between the amount of the specified substance and the volume of the system.
As for a substanc... |
After investigating what makes the persistent radical TEMPO stable, I was wondering if another compound which is more feasible for my needs would be comparable to it.
Would oxidizing 2,2’-dimethyl-diphenylamine result in a compound similar to TEMPO? It will have an Aminoxyl group and have the steric hindrance of the... |
I am quite a beginner in DFT and I am studying the theory behind the computational tools. I have some doubts about the Coulumb approximate functional term:
$$U[n] = \frac{1}{2} \int d^3 r \int d^3 r^\prime \frac {n(\mathbf{r}) n(\mathbf{r}^\prime)}{|\mathbf{r} -\mathbf{r}^\prime|}$$
If I use the definition of the el... |
I realise I did not give some time for the chemicals (which are releasing heat during an exothermic reaction) to cool down first and instead, I added another chemical substance to the reaction mixture immediately. Is it a red flag that I might lose some of my products and get a lower percentage yield? The experiment th... |
What happens if you do not allow time for an exothermic reaction to cool down? |
why is entropy maximum at equilibrium for a closed system? |
According to [Wikipedia's article about orbital hybridisation][1]:
> [...] today it is considered an effective heuristic for rationalising the
> structures of organic compounds. [...] Hybrid orbitals are assumed to be mixtures of atomic orbitals, superimposed on each other in various proportions.
So are $sp$, $s... |
According to [Wikipedia's article about orbital hybridisation][1]:
> [...] today it is considered an effective heuristic for rationalising the
> structures of organic compounds. [...] Hybrid orbitals are assumed to be mixtures of atomic orbitals, superimposed on each other in various proportions.
So are $\mathrm... |
We can split the reaction
$$\ce{H2O2 -> H2O + O2}$$
into the respective reduction and oxidation half-reactions.
$$\ce{H2O2 -> O2 + 2H+ + 2e-}$$
$$\ce{H2O2 + 2H+ + 2e- -> 2H2O}$$
Since the n-factor of $\ce{H2O2}$ for both these half-reactions is 2, [the n-factor is](https://chemistry.stackexchange.com/a/... |
I've seen a lot of reagents which have a slash between two compounds, such as Lindlar's catalyst which is H₂ along with Pd|BaSO₄. I know that the sulphur is a poison here but in general, what does the \ or | mean? And is it supposed to be a \ or a |? Are both equivalent? Does it mean "and" or "or" or something else?
... |
We can split the reaction
$$\ce{H2O2 -> H2O + O2}$$
into the respective reduction and oxidation half-reactions.
$$\ce{H2O2 -> O2 + 2H+ + 2e-}$$
$$\ce{H2O2 + 2H+ + 2e- -> 2H2O}$$
Since the n-factor of $\ce{H2O2}$ for both these half-reactions is 2, [the n-factor is](https://chemistry.stackexchange.com/a/... |
"How to verify that ethanol is infinitely soluble in water?".
You cannot do it because it is WRONG. And not because it is false for ethanol, it is simply plain wrong conceptually and mathematically.
Solubility is the ratio between the amount of the specified substance and the volume of the system.
As for a substanc... |
We can split the reaction
$$\ce{H2O2 -> H2O + O2}$$
into the respective reduction and oxidation half-reactions.
$$\ce{H2O2 -> O2 + 2H+ + 2e-}$$
$$\ce{H2O2 + 2H+ + 2e- -> 2H2O}$$
Since the n-factor of $\ce{H2O2}$ for both these half-reactions is 2, [the n-factor is](https://chemistry.stackexchange.com/a/... |
I've seen a lot of reagents which have a slash between two compounds, such as Lindlar's catalyst which is $\ce{H2}$ along with $\ce{Pd|BaSO4}$. I know that the sulphur is a poison here but in general, what does the \ or | mean? And is it supposed to be a \ or a |? Are both equivalent? Does it mean "and" or "or" or some... |
Is there a trend in alkali metal ion hydration entropy?
There's much talk of hydration enthalpy, but I have a hard time finding information about the change in entropy.
Am I right in thinking that Li$^+$ would have a more negative $\Delta S^o_{hyd}$ than Cs$^+$ because more water ligands will be ordered around ... |
What is the trend in hydration entropy of alkali metal ions? |
Can I solubilize lemon essence in water somehow? |
I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese(IV) oxide catalyst at 5 different temperatures:
$$\ce{2 H2O2 (l) ->[MnO2 (s)] O2 (g) + 2 H2O (l)}$$
Is there any way that I can find concentrations and then find the rate constant, $k$? And, using them, ma... |
Currently I am doing TD-DFT calculations in Gaussian and want to calculate transition dipole moment for $S_1$ transition manually. However, I do not manage to retrieve molecular orbital coefficients for the excited states in Gaussian, just the ground state with *population* keyword and a few hours of search through the... |
How to retrieve excited state molecular orbital coefficients in Gaussian? |
Imagine a vacuum flask-like container. If we filled the main compartment with helium and the vacuum compartment with high-pressure gas would helium still escape?
Let's ignore the leakage from the valve, the valve seating, o-rings, bushings, etc. |
I'm required to compare and justify the yields of my reactions against literature yields, but I cannot find any sources of literature yields for the reactions, or any reactions for that matter. Are there any resources with literature yields available?
The reactions are the formation of tetraphenylporphyrin and then ... |
Assume we want to calculate the heat capacities of two substances with different heat capacity. We heat them both up with a immersion heater delivering a constant rate of energy (constant J/sec), and we stop the immersion heater after 100 J of heat has been added. Would the lower heat capacity substance experience more... |
What databases do you have access to? A Scifinder search would find literature references with no difficulty.
A Google search finds this technical report which has the synthesis of tetraphenylporphyrin and the preparation of Fe(II) and Zn(II) complexes [report here][1].
The Cu(II) complex is prepared in this lab r... |
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