instruction stringlengths 15 21.8k |
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Can you find [SO32-] with just Ka1 and Ka2? |
The following diagram represents the kinetic scheme for cellulose which can be represented by the formula $\ce{C6H10O5}$:
![cellulose kinetic scheme][1]
The reaction rates for each pathway are first-order Arrhenius equations where $A$ is the pre-factor in $\mathrm{s^{-1}}$, $E$ is the activation energy in $\mathr... |
Sulfurous acid, $\ce{H2SO3}$, is a diprotic acid.
\begin{align}
K_{a1} &= 1.6 \cdot 10^{-2}\\
K_{a2} &= 6.4 \cdot 10^{-8}\\
\end{align}
Is it possible to find the concentration of $\ce{SO3^2-}$ from this?
I would think you would need to know the concentration of at least one thing. It is like trying to solve ... |
Can you find [SO₃²⁻] with just the two acid dissociation constants Kₐ₁ and Kₐ₂? |
My teacher isn't very good at helping me solve this problem, so I found this amazing website. I just have one question. I keep getting the answer but I don't know why I am getting it. Could you please help me understand this problem and why you should do this specific step?
> A $1.00~\mathrm{g}$ sample of $\ce{Na2CO... |
If you have a weak base XOH titrated with a strong monotonic acid, where do you start with that? Would you first have the base react with water and break up and determine how much of it does? Or just it breaking up alone, not reacting with water? Reacting just with the acid right away? I'm not sure where to start for t... |
If you have a weak base XOH titrated with a strong monotonic acid, where do you start with that? Would you first have the base react with water and break up and determine how much of it does? Or just it breaking up alone, not reacting with water? Reacting just with the acid right away? I'm not sure where to start for t... |
If you have a weak base XOH titrated with a strong monotonic acid, where do you start with that? Would you first have the base react with water and break up and determine how much of it does? Or just it breaking up alone, not reacting with water? Reacting just with the acid right away? I'm not sure where to start for t... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/xz80T.png
What will the products on addition reaction of 1,4-BENZOQUINONE with HBr ? |
![enter image description here][1]
[1]: https://i.stack.imgur.com/xz80T.png
What will the products on addition reaction of 1,4-benzoquinone with HBr ? |
I am doing a research and experiment on using Graphene oxide for deicing. My purpose is to coat graphene oxide on the surface of the ship in the north and south pole where large amount of large size ice cubes and icebergs are present. So when voltage is applied to it, it can generate a large amount of heat to melt the ... |
A reaction proceeds towards the direction of lesser Gibbs free energy (at constant $T$ and $p$). So, we could say that Gibbs free energy at equilibrium is _minimum_.
On the other hand, we have $$\Delta G=\Delta G^\circ + RT\ln Q$$, where $Q$ is the reaction quotient. At equilibrium, $Q=K_\text{eq}$, and we already k... |
[There](http://www.gizmag.com/scientists-create-forbidden-compounds-table-salt/30520/). And [there](http://www.sci-news.com/othersciences/chemistry/science-sodium-chlorides-foundation-chemistry-01633.html). Almost a year ago, a group of scientists claimed to have reached compounds of $\ce{Na}$ and $\ce{Cl}$ with weird ... |
Why is NaCl3 possible? |
Why is in the reaction of hydrogen peroxide and sodium hypochlorite, singlet oxygen obtained? Why isn't triplet oxygen produced instead, as it is thermodynamically more stable? |
Can I use my extech pH60 meter to measure soil pH if so how?
I included a link to the meter.
[Extech pH 60][1]
[1]: http://www.amazon.com/Extech-PH60-Waterproof-Meter-Temperature/dp/B0012W4HW2 |
Can I use my extech pH 60 meter to measure soil pH if so how? |
Someone please explain to me what is and what is the difference between Cis-Trans, E-Z and Syn-Anti Isomerization. I basically know mostly about cis trans and E-Z but have no idea about syn anti isomers.
Correct me if i am wrong-
cis trans isomers basically are when identical atoms or groups are on the same or o... |
>The volume of certain saturated solution is greater than the sum of the volumes of the water and salt from which it is made. On increasing pressure solubility of this salt
>(a) Increases
>(b) Decreases
>(c) Remains unaffected
>(d) Can't be predicted
The solution says
>Density of product < Density of... |
The answer is "(b) Decreases." The reason is that the saturated solution occupies more volume than the starting reagents. At higher pressures, creating this extra volume requires more $P dV$ work be done by the dissolving reagents.
> According to Le Chatelier's Principle, shouldn't equilibrium be shifted towards t... |
To start off, all chalcogens are known to form binary hydrides of the form $\ce{H2X}$ which can then behave as binary acids, however weak or strong, by the equation $\ce{H2X <=> HX^- + H+}$.
Now to compare the strength of the acids. The most straightforward way of doing this is comparing gas phase acidities, which ... |
Are methyl n-propyl ether and methyl iso-propyl ether metamers?
It says so here(http://chem-guide.blogspot.in/2010/04/introduction-nomenclature.html)
So the difference must be in number of carbon atoms or the distribution? |
Are methyl n-propyl ether and methyl iso-propyl ether metamers?
It says so [here](http://chem-guide.blogspot.in/2010/04/introduction-nomenclature.html).
So the difference must be in number of carbon atoms or the distribution? |
The answer is "(b) Decreases." The reason is that the saturated solution occupies more volume than the starting reagents. At higher pressures, creating this extra volume requires more $P dV$ work be done by the dissolving reagents.
> According to Le Chatelier's Principle, shouldn't equilibrium be shifted towards t... |
450 g chocolate Easter rabbit and end up eating the whole thing! The enthalpy of combustion of chocolate is −22.4 kJ/g. One kilogram of body fat contains 39 000 kJ of energy. Walking for an hour uses up 690 kJ of energy. For how many hours do you have to walk to use up the energy consumed?
So far I have calculated t... |
Are methyl n-propyl ether and methyl iso-propyl ether metamers?
It says so [here](http://chem-guide.blogspot.in/2010/04/introduction-nomenclature.html).
So the difference must be in number of carbon atoms or the distribution?
Definition(http://dictionary.reference.com/browse/metamerism) |
I've done absolutely no chemistry since high school. Now, 16 years later, I've been asked to look at some chemical analyses and I'm having trouble!
Context: I've got a series of spectroscopy results giving the concentrations (in mg/l) of chlorine and $SO_4$ in a sample. I want to find the molar and mass ratios o... |
Amount of substance of a molecule in a solute the same as amount of substance of constituent elements? |
all I know is that specific metals like Pb, Sn and Al become 'passive' in conc. nitric. Why in Nitric and not other conc. acids? Why only specific metals? Do they have something in common or are there individual reasons? |
what causes passivity of specific metals in conc. nitric? |
I've done absolutely no chemistry since high school. Now, 16 years later, I've been asked to look at some chemical analyses and I'm having trouble!
Context: I've got a series of spectroscopy results giving the concentrations (in mg/l) of chlorine and $\ce{SO4}$ in a sample. I want to find the molar and mass rati... |
If you have a weak base XOH titrated with a strong monotonic acid, where do you start with that? Would you first have the base react with water and break up and determine how much of it does? Or just it breaking up alone, not reacting with water? Reacting just with the acid right away? I'm not sure where to start for t... |
The energy band of valence electrons gets smaller and smaller when the lattice (bulk) atoms are more and more separated from each other, until discrete energy levels are formed, due to the isolation of the atoms from each other (see image below).
What happens with energy levels of core electrons in the bulk, as the ... |
I was wondering whether the following order is correct :
- In the **first inequality,** how come 9 hyperconjugation dominated resonance effect of benzene ring?
- In the **last inequality** doesn't 2 hyperconjugation of vi... |
Do core electrons in bulk material have discrete energy levels or continuous energy band? |
The energy band of valence electrons gets smaller and smaller when the lattice (bulk) atoms are more and more separated from each other, until discrete energy levels are formed, due to the isolation of the atoms from each other (see image below).
What happens with energy levels of core electrons in the bulk, as the ... |
> What happens with energy levels of core electrons in the bulk, as the
> lattice constant is changed? Do they form a continuous energy band in
> the first place? Why?
Using an organic example, as you move from ethylene to butadiene to hexatriene, you have 1, 2 and 3 bonding and antibonding pi molecular orbitals r... |
Here is something I found, on weak polyprotic acids, that I think answers the question:
![enter image description here][1]
[1]: https://i.stack.imgur.com/9I2Cu.png
So then [SO2−3] would approximately equal 6.4*10^-8? |
Here is something I found, on weak polyprotic acids, that I think answers the question:
![enter image description here][1]
[1]: https://i.stack.imgur.com/9I2Cu.png
So then [$\ce{SO2^{−3}}$] $= 6.4 \cdot 10^{-8}$? |
Suppose I eat a whole $450~ \rm{g}$ chocolate Easter rabbit. The enthalpy of combustion of chocolate is $−22.4~\rm{ kJ/g}$. One kilogram of body fat contains $39000 ~\rm{kJ}$ of energy. Walking for an hour uses up $690 ~\rm{kJ}$ of energy.
>For how many hours do I have to walk to use up the energy consumed?
So f... |
Suppose I eat a whole $450~ \rm{g}$ chocolate Easter rabbit. The enthalpy of combustion of chocolate is $−22.4~\rm{ kJ/g}$. One kilogram of body fat contains $39000 ~\rm{kJ}$ of energy. Walking for an hour uses up $690 ~\rm{kJ}$ of energy.
For how many hours do I have to walk to use up the energy consumed?
So fa... |
I know that specific metals like $\cf{Pb}, \cf{Sn}$ and $\cf{Al}$ become passive in conc. nitric acid. My questions are:
> * Why does this happen only with conc. nitric acid, and not other conc. acids?
* Why is the passivity specific to these metals? Do they have something in common or are there individual reasons... |
What causes passivity of specific metals in conc. nitric acid? |
I know that specific metals like $\cf{Pb}, \cf{Sn}$ and $\cf{Al}$ become passive in conc. nitric acid. My questions are:
* Why does this happen only with conc. nitric acid, and not other conc. acids?
* Why is the passivity specific to these metals? Do they have something in common or are there individual reasons... |
What happens when alkynes react with Sodium or soda amide?
Does it liberate hydrogen so does it prove that alkynes are acidic?
What happens when But-1-yne and but-2-yne react with Sodium and soda amide... Please write the reactions.
|
On G2:M1:V1 window, result summary is grayed out. Does anybody know how to enable so that I can see my calculation summary? |
A strong electrolyte is an electrolyte that completely, or almost completely, ionizes or dissociates in a solution.
My book has a question:
> In a saturated solution of sparingly soluble strong electrolyte $\ce{AgIO3}$ the equilibrium with sets in is $\ce{AgIO3→Ag+ + IO3-}$
Is the above statement wrong or is th... |
Can a strong electrolyte be sparingly soluble? |
Can you explain to me:
* What are Cis-Trans, E-Z and Syn-Anti Isomerization?
* What is the difference between them?
* How many functional groups is cis-trans isomerism applicable to?
I know mostly about cis trans and E-Z but have no idea about syn- anti isomers. Correct me if needed: I think cis and trans i... |
To my understanding, dehydration is defined as a subset of a condensation reaction. A condensation defined as being two molecules joining together (in the case of loss of water, this is referred to as a dehydration).
I also thought however, if a molecule of water leaves without a condensation necessarily occurring, ... |
From http://chemistry.stackexchange.com/q/27455/1071 I confirmed that nitrogen is used to exclude oxygen - in order to prevent oxidation of the material.
Can $CO_2$ be substituted for nitrogen, or will the presence of carbon dioxide slow down the decarboxylation reaction (which is *causing carbon dioxide to be relea... |
Suppose I am given some reaction in which
$$\ce{C6H12O6 -> CO2}$$
and I want to calculate n-factor for this reaction to ultimately calculate equivalent weight of carbon for this reaction. Since $$E=\frac{M}{n}$$
I know that n-factor is no of electron gained/lost by one atom of a compound.
So Initial Oxidation st... |
How to calculate valence factor (n-factor) for a element? |
Suppose I am given some reaction in which
$$\ce{C6H12O6 -> CO2}$$
and I want to calculate n-factor for this reaction to ultimately calculate equivalent weight of carbon for this reaction. Since $$E=\frac{M}{n}$$
I know that n-factor is no of electron gained/lost by one atom of a compound.
So Initial Oxidation st... |
Hint :
n-factor is defined as the change in oxidation state **per molecule**.
You have correctly calculated the change of **one** carbon atom as 4.
But how many carbon atoms are there in the glucose molecule?
Note:
The **average** oxidation state of carbon in glucose is zero while in reality the... |
I can't find any publication to deal with aggregation of colloidal metalic nanoparticles. What type of interaction(s) is/are there between aqeous metalic nanoparticles which give(s) rise to aggregation? |
I want to optimize geometry and to analyse frequencies for transition metals ($\ce{Cu}$, $\ce{Mn}$, etc.) compounds using GAMESS. I use Avogadro for preparing input files and I have a problem: one of my calculations terminates abnormally with the following message in the output file.
> NO FORCE FIELD, SCF DOES NOT C... |
Most resources on pH and the electrochemistry behind it that I've found are IMHO too superficial. For example, they explain that an electrode with less than 80% slope should be discarded, but not why the decrease in slope happens, or why it's a problem if you can just calibrate it. Or they explain the potential generat... |
What's a good resource/book on pH measurements? |
[According to Wikipedia][1], there's an infinite set of possible wavefunctions (orbitals) for the hydrogen atom:
$$\psi_{n\ell m}(r,\theta,\phi) = \sqrt {{\left ( \frac{2}{n a_0} \right )}^3\frac{(n-\ell-1)!}{2n[(n+\ell)!]} } e^{- r/na_0} \left(\frac{2r}{na_0}\right)^{\ell} L_{n-\ell-1}^{2\ell+1}\left(\frac{2r}{na_0}... |
Why hydrogen has so many wavefunction associated with it? |
>1.Would an unperturbed electron ever go outside the lowest orbital?
First, there is no such thing as "outside the lowest orbital" because the lowest orbital has probablity density at all points is space (no nodes).
But yes, at a given temperature electrons will be distributed amoung the energy levels in accord... |
>1.Would an unperturbed electron ever go outside the lowest orbital?
First, there is no such thing as "outside the lowest orbital" because the lowest orbital has probability density at all points in space (no nodes).
But yes, at a given temperature electrons will be distributed amoung the energy levels in accor... |
>1.Would an unperturbed electron ever go outside the lowest orbital?
First, there is no such thing as "outside the lowest orbital" because the lowest orbital has probability density at all points in space (no nodes).
But yes, at a given temperature electrons will be distributed amoung the energy levels in accor... |
Why is *p*-methoxyphenol more acidic than *p*-methylphenol?
According to me, inductive effect really doesn’t matter at para positions and *p*-methoxyphenol should be less acidic due to the high mesomeric effect of the $\ce{-OCH3}$ group in comparison to the weak hyperconjugative effect of the $\ce{-CH3}$ group.
[... |
Why is p-methoxyphenol more acidic than p-methylphenol? |
I have these two questions in my lab manual and I don't know how to approach them.
1) Which is the better solvent for molar mass determinations by freezing point depression, benzene or cyclohexane?
2)Which is the better method for molar mass determination, freezing point depression or boiling point elevation?
For ... |
What is the mechanism of the reduction of organic acids with borane? Borane reductions don't work well with electron deficient carbonyl groups. Why is that so, and how isn't the carboxyl group an electron deficient group? |
Why are so many wave functions associated with hydrogen? |
How concentrated can an acid be without it being supersaturated? Is there a certain limit to how concentrated an acid or base can be?
When I mean concentration, I mean molarity; so how concentrated can an acid or base be?
----------
**NOTE:** Can be a *strong* or *weak* acid/base. Because we are just looking ... |
How concentrated can an acid be? |
Often called "hypervalent", chemicals like Phosphorous Pentachloride and Sulfur Hexaflouride are possible due to the fact that their central atoms form covalent bonds with more than four other atoms, giving rise to uncommon arrangements. In the case of PCl5, the Phosphorous atom forms 5 bonds, giving rise to trigonal b... |
What is the highest possible expanded octet? |
Often called "hypervalent", chemicals like Phosphorous Pentachloride and Sulfur Hexaflouride are possible due to the fact that their central atoms form covalent bonds with more than four other atoms, giving rise to uncommon arrangements. In the case of $\ce{PCl_5}$, the Phosphorous atom forms 5 bonds, giving rise to tr... |
According to the VSEPR model, when a molecule in formed in the shape of AB(x),
> like IF7, SCl6, and PCl5,
its structure is found by reducing the repulsions between peripheral atoms. This gives rise to many shapes, most of which have constant bond angles. Examples of those with constant bond angles include
> C... |
Why do many hypervalant chemicals have non-constant bond angles? |
Often called "hypervalent", chemicals like Phosphorous Pentachloride and Sulfur Hexaflouride are possible due to the fact that their central atoms form covalent bonds with more than four other atoms, giving rise to uncommon arrangements.
In the case of $\ce{PCl_5}$, the Phosphorous atom forms 5 bonds, giving rise to... |
According to the VSEPR model, when a molecule in formed in the shape of $\ce{AB_{x}}$,
> like $\ce{IF7}$, $\ce{SCl6}$, and $\ce{PCl5}$,
its structure is found by reducing the repulsions between peripheral atoms. This gives rise to many shapes, most of which have constant bond angles. Examples of those with consta... |
All of the exams that I've sat so far, and the homework questions I've had, always ask for the reaction between a substance and a **dilute acid**. Is there a difference in the reaction between a dilute acid and a 'concentrated' acid when each is applied to a substance? If so, what is it, and how dilute is dilute? |
Why do exam questions specify "dilute acid"? |
I have a problem solivng this chemical problem. Any help would be highly appreciative.
Sodium Thiosulfate can be made by the reaction
Na_2(CO_3) + 2Na_2(S) + 4SO_2 ---> 3Na_2(S_2)O_3 + CO_2
Question: How many grams of Na_2(S) are required to react with 25.0 g of Na_2(CO_3) if SO_2 is present in excess?
My ... |
I have a problem solivng this chemical problem. Any help would be highly appreciative.
Sodium Thiosulfate can be made by the reaction
$\ce{Na_2CO_3 + 2Na_2S + 4SO_2 -> 3Na_2S_2O_3 + CO_2}$
Question: How many grams of $\ce{Na_2S}$ are required to react with 25.0 g of $\ce{Na_2CO_3}$ if $\ce{SO_2}$ is present i... |
I have a problem solivng this chemical problem. Any help would be highly appreciative.
Sodium Thiosulfate can be made by the reaction
$\ce{Na_2CO_3 + 2Na_2S + 4SO_2 -> 3Na_2S_2O_3 + CO_2}$
Question: How many grams of $\ce{Na_2S}$ are required to react with 25.0 g of $\ce{Na_2CO_3}$ if $\ce{SO_2}$ is present i... |
I want to know why concentration of solids and liquids are taken unity in expression of equilibrium constant( heterogenous equilibrium). It is usually mentioned that the density of solids and liquids( ideally) does not change and hence concentration does not change and so rate does not depend on solids and liquids. I a... |
The concentration is unity! Why? |
The standard example is CrCl3.6H20, which can have three distinctly different
crystalline compounds, now known as [Cr(H20)6]Cl3 (violet), [CrCl(H20)5]Cl .H20
(blue-green), and [CrCl2(H20)4]Cl.2H20 (dark green).
how does this difference of ligands in octahedral system affecting the colour of compound? What I think is... |
How hydrate isomerism results difference in colours? |
what is products of haloform reaction of acetylacetone? |
I searched a lot to know the products of haloform reaction of acetylacetone but I didn't find any result please help.
What are products of haloform reaction of acetylacetone? |
Products of haloform reaction of acetylacetone? |
I searched a lot to find the products of the haloform reaction of acetylacetone, but I didn't find any result.
What are the products of the haloform reaction of acetylacetone? |
The standard example is $\ce{CrCl3.6H2O}$, which can have three distinctly different
crystalline compounds now known as
$\ce{[Cr(H2O)6]Cl3}$ (violet),
$\ce{[CrCl(H2O)5]Cl .H2O}$
(blue-green), and
$\ce{[CrCl2(H2O)4]Cl.2H2O}$ (dark green).
How does this difference of ligands in octahedral system affect th... |
I know that sulfuric acid is considered a strong acid, and the dissociation of its first H+ ion is complete and of its second H+ ion is partial.
Phosphoric acid is weak and all three of its H+ ions dissociate partially.
I just wanted to clarify- for dibasic and tribasic acids, are they considered strong if their ... |
Confused about strong/weak dibasic and tribasic acids? |
This is rather a bunch of questions that I decided to post on Chemistry StackExchange since I thought the chemists would have the most knowledge about the chemical processes of life.
So recently I have came across stem cells and a lot of revolutionary medical products that can rebuild tissue and even organs.
And ... |
Can we prolong life? |
If we have a metal in gas phase.Suppose lets say Aluminium.Aluminium has delocalised electrons.There is Al cation -electron attraction in it.Its easier to visualize Al atomic structure in solid form.But if its in gas phase will delocalised electrons return to the atom itself or there is going to be electrons and cation... |
If we have a metal in gas phase. Suppose lets say Aluminum. Aluminum has delocalised electrons. There is Al cation -electron attraction in it. Its easier to visualize Al atomic structure in solid form. But if its in gas phase will delocalised electrons return to the atom itself or there is going to be electrons and cat... |
Hint :
n-factor of a molecule/compound is defined as the change in oxidation state **per molecule**.
You have correctly calculated the change of **one** carbon atom as 4.
But how many carbon atoms are there in the glucose molecule?
Note:
* The **average** oxidation state of carbon in glucose... |
Not that long ago, scientists noticed that at the end of each DNA strand there were thousands of nucleotides. Nucleotides are used for genetic coding. That is to say, certain sequences of nucleotides instruct the body to synthesize certain proteins when the genetic code in the DNA is being read. DNA is really like ... |
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