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A 100 ml solution of NaOH has a pH of 13. What volume of water, in mL must be added to change the pH to 11?
My Steps:
- So, begin by calculating conc. of [OH-] for pH 13.
- Then find the moles by conc. X volume (0.1 L)
- Then by determining new conc. of [OH-] for pH 11.
- Then by doing *moles/new conc* t... |
I tried to look up the way to do this question but I could not find any helpful information in order to help me solve this question.
Q: Using the following salts listed below, calculate the moles of acid and conjugate base needed to make 100 ml of 0.50 M, pH 6.5, 6.7, 6.8 phosphate buffer solutions. (For H2PO4, pKa ... |
what is the origin of the colour of azo-dyes? Is it the same reason as to why transition metal complexes have colour? |
what is the origin of the colour of azo dyes? |
I tried to look up the way to do this question but I could not find any helpful information in order to help me solve this question.
**Q**: Using the following salts listed below, calculate the moles of acid and conjugate base needed to make $V = 100 mL$ of $c = 0.50 M$, $pH \in 6.5, 6.7, 6.8$ phosphate buffer solut... |
> Number of moles of $\ce{MnO_4^-}$ required to oxidize one mole of ferrous oxalate completely in acid medium will be:
>(a) 7.5 moles
>(b) 0.2 moles
>(c) 0.6 moles
>(d) 0.4 moles
In acidic medium, 1 mole of $\ce{MnO_4^-}$ accepts 5 moles of electrons. Oxalate is dibasic so will give 2 moles of electron... |
I would like to ask what are the main differences between doxycycline hcl and hyclate?
I work in the pharmaceutical/veterinary raw materials industry and some clients are saying that they prefer hyclate because it is more concentrated than hcl. But I have yet to come on any articles confirming this. Is this true? |
What is the difference between doxycycline hcl and doxycycline hyclate? |
I was told that 'water' was the most common material in the universe and I disputed that claim. I was met with the argument that hydrogen and oxygen were the most common atoms in the world so water was as well. If this is true, then how come we can't find water anywhere in outer space? It must be the collection of 2 hy... |
I recently read about potassium aluminum sulfate that it has astringent property and has the ability to constrict body tissues and restrict blood flow. Since, for penis, the erection happens with the flow of the blood being directed to penis' blood vessels, does this effect of potassium aluminum sulfate cause an erecti... |
Does potassium aluminum sulfate have any effect on sexual performance/sperm counts or anything relating to the functionality of the sexual organs? |
I am currently studying computational chemistry and I am trying to understand the UV-VIS absorption of molecules. I know that UV-VIS absorption is electronic excitation and requires a specific energy.
What I don't understand is why a molecule can not absorb a shorter wavelength as it has more energy? A slightly hig... |
I am currently studying computational chemistry and I am trying to understand the UV-VIS absorption of molecules. I know that UV-VIS absorption is electronic excitation and requires a specific energy.
What I don't understand is why a molecule can not absorb a shorter wavelength as it has more energy? A slightly hig... |
I am currently studying computational chemistry and I am trying to understand the UV-VIS absorption of molecules. I know that UV-VIS absorption is electronic excitation and requires a specific energy.
What I don't understand is why a molecule can not absorb a shorter wavelength as it has more energy? A slightly hig... |
According to Molecular Orbital Theory(MOT), the bond order of CO is 3. When CO+ is formed, bond order decreases to 2.5 and thus bond length should increase. However, the bond length of CO+ is found to be less than CO. Why is it so? |
Bond Length of CO+ is expected to be more than CO but it is found to be more. Why is this so? |
Bond Length of CO+ is expected to be more than CO but it is found to be less. Why is this so? |
http://www.meta-synthesis.com/webbook/39_diatomics/co.jpg <BR>
Measured $\ce{CO}$ bond length is 1.128 Å, $\ce{CO^{+}}$ is 1.115 Å. Given the following carbon monoxide MO diagram, from where is the electron removed to afford the cation with a shorter bond length? $\ce{CO}$ has a dipole moment of 0.122 debyes, net ne... |
Is it the same as transition metal colors? If you define this as "an electron is promoted to a higher energy state" and that photon absorption defines the color then the answer is yes. If you define it as an absorption by d orbitals then the answer is no. As others have indicated these dyes can absorb in the visible ... |
I'm taking entry level collage chem. class, and we got to this topic that I don't really understand. I think I understood what an ion is (a atom whose amount of electrons is not equal to amount of protons, so it has positive or negative charge). But then polyatomic ions... Lets say peroxide; consists of two Oxygens, wh... |
Charge of polyatomic ions doesn't equal the charge of ions it consists of? |
Free chlorine ($\ce{Cl}$) in the stratosphere can deplete ozone ($\ce{O3}$) as follows:
$$\ce{Cl + O3 -> ClO + O2}$$
The chlorine atoms can then react with oxygen and return to the beginning of the cycle:
$$\ce{ClO + O -> Cl + O2}$$
The EPA [estimates](http://www.epa.gov/ozone/science/process.html) the ozone-d... |
Why does free chlorine in the stratosphere lose its ozone-depleting potential after about 100,000 reactions? |
Basically can someone explain why the molecularity cannot be determined from the rate law? |
Why can't the molecularity be determined from the rate law? |
How would you draw the mechanism going from 3-nonenoic acid to coconut aldehyde? I know I added Sulfuric acid and sodium carbonate which I was confused how they worked into the mechanism. I am certain there is some type of internal reaction to create the five membered ring. |
>I've also read online that adding $\ce{H2O2}$ and $\ce{H2SO4}$ creates a "Piranha" solution [...]
This is true - in principle. In reality, [*Piranha solution*][2] is made from **concentrated** sulfuric acid and **30%** hydrogen peroxide.
In the case of your experminent, you will most likely use diluted sulfuric ... |
How would you draw the mechanism going from 3-nonenoic acid to coconut aldehyde? I know I added Sulfuric acid and sodium carbonate which I was confused how they worked into the mechanism. I am certain there is some type of internal reaction to create the five membered ring.
Those are the only chemicals that could,... |
I am performing an experiment with DTZA and Ferrate. After a point of increasing the DTZA concentration too much the Ferrate takes longer(Slower reaction rate) to react with the DTZA. Is this something reasonable or is it due to error? |
Exceesive Reactant can result in slowing down reaction time? |
SiH4 and CH4
The only intermolecular force they both have is London Dispersion forces
Strength of LDF is determined by molar mass
molar mass of SiH4 = 32.132
molar mass of CH4 = 48.42
Therefore shouldn't CH4 have a stronger LDF??
The answer says that SiH4 has a greater intermolecular force...why is ... |
Determine which molecule has stronger intermolecular force? |
#What is the origin of colors?
Most of the colors that we perceive are originate by the selective absorption of some spectral bands and the reflection of the others wavelength, some times with the contribution of fluorescence from the absorption at higher wavelength. If we exclude color due to interference (e.g. some ... |
#What is the origin of colors?
Most of the colors that we perceive are originate by the selective absorption of some spectral bands and the reflection of the others wavelength, some times with the contribution of fluorescence from the absorption at higher wavelength. If we exclude color due to interference (e.g. some ... |
Figuring out the theoretical mass of reactants? |
What role does heat play in the combustion process.Specifically, does the amount of heat determine whether complete or incomplete combustion occurs? |
Try to answer to these questions, don't cheat, check the answer passing over the yellow box.
I think this software is confusing you always start from how much reactants you have and then calculate how much products you will have, suppose you have 100 g of oxygen and 44 g of propane.
How many mole of propa... |
Try to answer to these questions, don't cheat, check the answer passing over the yellow box.
I think this software is confusing you always start from how much reactants you have and then calculate how much products you will have, suppose you have 100 g of oxygen and 44 g of propane.
How many mole of propane... |
Try to answer to these questions, don't cheat, check the answer passing over the yellow box.
I think this software is confusing you always start from how much reactants you have and then calculate how much products you will have, suppose you have 100 g of oxygen and 44 g of propane.
How many mole of propane... |
In contrast, the explosion of triacetone triperoxide (83% the pop of TNT) has hard by zero exotherm. Ambient oxygen makes no difference. Much of the acetone can be recovered and reused - a near-zero carbon footprint, highly recyclable terrorist explosive. Why do people complain? J. Am. Chem. Soc. 127, 1146 (2005)
... |
There are multiple reactions going on simultaneously. Aluminum metal reacts with the oxygen in surrounding air in order to create a plating of aluminum (III) oxide.
$$\ce{4Al(s) + 3O2(l) → 2Al2O3(s)}$$
Upon addition of sodium hydroxide, the oxide layer reacts with the base, leaving the aluminum free to attack by ... |
Yes, **temperature** and **heat** do affect the **spontaneity** and the **equilibrium** of reactions. The term heat can be referred to enthalpy, which can be quite confusing in context, as I believe you are asking about raising the temperature.
Let's first take a look at the equation for the Gibb's Free Energy and ... |
Yes, **temperature** and **heat** do affect the **spontaneity** and the **equilibrium** of reactions. The term heat can be referred to enthalpy, which can be quite confusing in context, as I believe you are asking about raising the temperature.
Let's first take a look at the equation for the Gibb's Free Energy and ... |
Quick question, in this reaction:
2-Butenal + CH3MgBr --> ??
Will the grignard attack the double-bond or the aldehyde carbon?
Please explain this preference, thanks! |
In class we performed an experiment which I am unable to understand the results for
Why does the the amount of soot produced vary? What is the amount of soot produced dependent on?
**
***Experiment:***
**
In this lab we had to have four test tubes upside down in a beaker of water. The test tubes were filled... |
Why is a sugar solution pre-treated with ammonium hydroxide before analyzing? And why is it specifically ammonium hydroxide instead of sodium hydroxide or calcium hydroxide?
|
Why is NH4OH used in Polarimetric analysis? |
*Let me first say that I don't know this specific reaction, so I am not sure whether my answer holds for it, but let me answer the general question: can a high concentration slow down the reaction rate?*
The answer is, yes it can. The mechanism by which this happens is called [inhibition][1] and it is often (althoug... |
I am performing an experiment with DTZA and Ferrate. After a point of increasing the DTZA concentration too much the Ferrate takes longer (lower reaction rate) to react with the DTZA. Is this something reasonable or is it due to error? |
Can an excessive reactant amount result in a longer reaction time? |
CH4 + O2 => CO2 + 2H2, what's wrong with it? |
From Miessler's Inorganic Chemistry, 5th edition, there is this correlation diagram for $d^{2}$ in a octahedral field.
![correlation diag][1]
On the left hand side, if it's not clear, it goes (from lowest to highest):
$^{3}F, ^{1}D, ^{3}P, ^{1}G, ^{1}S$.
But by Hund's rules mentioned even in the same chapt... |
Correlation Diagram Doesn't Match Selection Rules? |
I have the impression that you a very close to find the answer yourself!
I will not give a full answer here, but some hints.
> [...] I know I added Sulfuric acid and sodium carbonate [...]
Let's assume that you did not add them simultaneously. Then, it seems likely that sulfuric acid *does the magic* and sodi... |
I'm not sure if this is a silly question, but I was sitting here with a cup full of cheezey poof balls thinking, "My goodness, it's like an amazing cheesey delicious liquid - huge water molecules!"
Of course my next thought was, "Wait a minute - water has two hydrogen atoms bonded to an oxygen, so that's not quite r... |
Are atoms really round? |
If you can find a single atom in vacuum with a net dipole moment, its electron cloud is obviously not spherically symmetric. Go across the periodic table's second row. They are all $\ce{1s^2}$ $\ce{2s^2}$, so their atomic cores absent chemical combination and hybridization are first order spherically symmetric, fille... |
Look at the enthalpies of formation of $\ce{CO}$, $\ce{CO2}$, and $\ce{H2O}$, then the net enthalpies of reaction. In a deficiency of oxygen, and trimmed by the temperature and kinetics versus equilibrium conditions, are you more likely to obtain $\ce{CO}$ plus $\ce{H2O}$ than free hydrogen? Given less oxygen, soot a... |
Do you see a potential corresponding to the sugars, or to their Schiff bases, or to said imines' trimers? Perhaps ammonia gives you a nice pH buffer, as opposed to alkali hydroxides that will wildly swing pH and allow Cannizzaro disproportionation of reducing sugars' aldehyde groups at high pH. Ammonia does not reduce... |
I'm not sure I have answer to your question maybe, if you consider natural colorant too, these are the articles that go more close to what you want:
[Prediction of phenolic compounds in red wine fermentations by visible and near infrared spectroscopy](http://www.sciencedirect.com/science/article/pii/S000326700301154... |
Preference of grignard between aldehyde and double bond? |
So I suspect that you would have both these molecular equations:
$\ce{2KCl(aq) + Na2SO4(aq) -> K2SO4(aq) + 2NaCl(aq)}$
$\ce{Ca(NO3)2(aq) + Na2SO4(aq) -> 2NaNO3(aq) + CaSO4(aq)}$
To answer your question with "What is a complete reaction?":
>"A complete reaction is one where all of at least one of the availab... |
Copper(II) is a hard Lewis acid that would be octahedrally coordinated but for Jahn-Teller distortion. Instead it is square-planar coordinated with two distant weakly bound apical ligands. The lovely deep blue color, hard Lewis base ammonia versus hard Lewis acid water coordination, illustrates the nephelauxetic effe... |
Yes, **temperature** and **heat** do affect the **spontaneity** and the **equilibrium** of reactions. The term heat can be referred to enthalpy, which can be quite confusing in context, as I believe you are asking about raising the temperature.
Let's first take a look at the equation for the Gibb's Free Energy and ... |
Is the double bond *cis* ${Z}$ or *trans* ${E}$? (Terrible nomenclature.) What is the scent of the product? What is it commonly called? Don't taste it. A tiny bit on your tongue will excavate a deep ulcer. The ${E}$-isomer melts at -7.5 C. How did you get the putative ${Z}$-isomer, and how can it melt at least 40 ... |
If $\ce{NaCl}$ is such a strongly bonded ionic compound, why it does it disassociate so readily in $\ce{H2O}$? One would think that because of the very strong ionic bond it would not disassociate it all. Further, why do other compounds like $\ce{AgCl}$ or $\ce{HF}$ not disassociate as readily even though they also have... |
Why does $\ce{NaCl}$ ionize in $\ce{H2O}$ despite its strong ionic bond? |
Why does $\ce{Pb}$ has an oxidation number of $2^{+}$ while carbon and others in the same group have an oxidation number of $4^{+}$?
Further, why doesn't carbon also have a $2^{+}$ oxidation number, as can't it also give up its two electrons in the p-suborbital to have a full s-suborbital? Why does it prefer to gai... |
Why does $Pb$ normally have an oxidation number of $2+$? |
There are multiple reactions going on simultaneously. Aluminum metal reacts with the oxygen in surrounding air in order to create a plating of aluminum (III) oxide.
$$\ce{4Al(s) + 3O2(l) -> 2Al2O3(s)}$$
Upon addition of sodium hydroxide, the oxide layer reacts with the base, leaving the aluminum free to attack by... |
I am told that in a chemical equation the metal comes first and then the non metal. for example MgO, ZnSO<sub>4</sub>,etc. But when both the elements are non metals or metals, the one with the lower atomic number would come first. for example:- H<sub>2</sub>O,CO<sub>2</sub>,HF,etc. But why is it that hydroxide is OH- a... |
Why is it OH- and not HO-? |
Say I promote a molecule to a triplet state via repeated fluorescent excitation events. Prior to returning to the ground state via phosphorescence or a reverse intersystem crossing event, let's say that the triplet $T_1$ state molecule reacts with a reducing agent via an exothermic bond formation process, and that the... |
Say I promote a molecule to a triplet state via repeated fluorescent excitation events. Here, this is going to mean that an electron from the HOMO level, originally with a spin-UP and spin-DOWN electron, will be promoted to the LUMO level s.t. its spin is the same as the electron left-over in the HOMO level (we can th... |
Say I promote a molecule to a triplet state via repeated fluorescent excitation events. Here, this is going to mean that an electron from the HOMO level, originally with a spin-UP and spin-DOWN electron, will be promoted to the LUMO level s.t. its spin is the same as the electron left-over in the HOMO level (we can th... |
Say I promote a molecule to a triplet state via repeated fluorescent excitation events. Here, this is going to mean that an electron from the HOMO level, originally with a spin-UP and spin-DOWN electron, will be promoted to the LUMO level s.t. its spin is the same as the electron left-over in the HOMO level (we can th... |
Say I promote a molecule to a triplet state via repeated fluorescent excitation events. Here, this is going to mean that an electron from the HOMO level, originally with a spin-UP and spin-DOWN electron, will be promoted to the LUMO level s.t. its spin is the same as the electron left-over in the HOMO level (we can th... |
I know that cyclopropyl methyl carbocation is exceptionally stable compared to say, benzyl carbocation.
But I want to know how stable is cyclobutyl methyl carbocation compared to say, tertiary/secondary carbocations? Or, will it go rearrangement breaking the ring? |
Say I promote a molecule to a triplet state via repeated optical excitation events. Here, this is going to mean that an electron from the HOMO level, originally with a spin-UP and spin-DOWN electron, will be promoted to the LUMO level s.t. its spin is the same as the electron left-over in the HOMO level (we can then u... |
Say I promote a molecule to a triplet state via repeated electronic excitation events. Here, this is going to mean that an electron from the HOMO level, originally with a spin-UP and spin-DOWN electron, will be promoted to the LUMO level s.t. its spin is the same as the electron left-over in the HOMO level (we can the... |
We're looking at a case of PET (photoinduced electron transfer) with electron back transfer between an (electron) acceptor **A** and a donor **D** here.
For organic dyes, the ground state typically is a singlet state ($S_0)$, excitation of **A** yields an excited singlet state (typically $S_1$).
$\ce{A ->[h\nu]\... |
I want to do intra molecular aldol condensation of 7-oxo octanal.
![enter image description here][1]
I am talking about the major product. Clearly, A 6-membered ring would be a major product, but there are 2 possibilities. Taking Hydrogen from $C_2$ or $C_6$. Which one would be preferred?
[1]: https://i.stac... |
Thanks a lot Michiel I got the answer in the Fischer-Tropsch process. During normal atmospheric pressure the following reaction occurs :
CO + 3H<sub>2</sub> = CH<sub>4</sub> + H<sub>2</sub>O
Also could someone tell me the type of reaction this is? I think it is partially a displacement reaction for O is displa... |
Why does $\ce{Pb}$ have an oxidation number of $2^{+}$ while carbon and other elements in the same group have an oxidation number of $4^{+}$?
Furthermore, why doesn't carbon also have a $2^{+}$ oxidation number, as can't it also give up its two electrons in the p-suborbital to have a full s-suborbital? Why does it ... |
*Why can't lead gain four electrons?* The lower you go on the periodic table, the lesser you will find elements that have a more non-metallic character (so with this I mean elements that will have a lower tendency to gain electrons). Just visualize a lead atom with a very small nucleus and a large area surrounding the ... |
*Why can't lead gain four electrons?* The lower you go on the periodic table, the lesser you will find elements that have a more non-metallic character (so with this I mean elements that will have a lower tendency to gain electrons). Just visualize a lead atom with a very small nucleus and a large area surrounding the ... |
Suppose A(+)B(-) type fused salt is present in an electrolytic cell (not electrochemical cell). Let n electrons be entering the cell per second. Since each A(+) requires one electron to discharge, so n electrons will discharge n A(+) per second. Similarly, n B(-) are also discharged per second because the number of ele... |
Hi I have decided to give chemistry another shot (it didn't take so well way back in high school). My main interest is for reading up on brain chemistry and pharmacology.
I currently have a textbook on inorganic chemistry [Introduction to Organic Chemistry 3rd edition: William Brown.Thomas Poon] that I picked up and... |
Which branches of chemistry and in what order to learn (self study)? |
We're looking at a case of PET (photoinduced electron transfer) with electron back transfer between an (electron) acceptor **A** and a donor **D** here.
For organic dyes, the ground state typically is a singlet state ($S_0)$, excitation of **A** yields an excited singlet state (typically $S_1$).
$\ce{A ->[h\nu]\... |
In my textbook, a statement is given, as follows:
> Boiling point of a liquid increases with increase in temperature
However, I was wondering, isn't it wrong. The boiling point of a liquid always remains the same, it doesn't change.
Hence, my question is:
> Is the above statement wrong? If it is, then unde... |
Boiling point of a liquid increasing with temperature? |
In my textbook, a statement is given, as follows:
> Boiling point of a liquid increases with increase in temperature
However, I was wondering, isn't this wrong? The boiling point of a liquid always remains the same, it doesn't change.
Hence, my question is:
**Is the above statement wrong? If it is, then unde... |
In equation of gibbs free energy change (delta g) = (delta h)-T*(delta s) ,is T system's or surrounding's temperature? |
T is the temperature of what? |
In equation of gibbs free energy change $(\Delta G) = (\Delta H)-T*(\Delta S)$,is T system's or surrounding's temperature? |
In equation of gibbs free energy change $\Delta G = \Delta H-T\Delta S$,is T system's or surrounding's temperature? |
In equation of gibbs free energy change $\Delta G = \Delta H-T\Delta S$,is T system's or surrounding's temperature?
Edit:Oh sorry I am not clear earlier now I get clear question.I know we have to calculate gibbs free energy of system but criterion for spontaneity of $\Delta Stotal$ should be greater than zero.When w... |
In equation of gibbs free energy change $\Delta G = \Delta H-T\Delta S$,is T system's or surrounding's temperature?
Edit:Oh sorry I am not clear earlier now I get clear question.I know we have to calculate gibbs free energy of system but criterion for spontaneity of $\Delta Stotal$ should be greater than zero.When w... |
When water is added to a weak acid like ethanoic aicd, number of ethanoic acid molecules that dissociate increases however, pH increases (less acidic)... but why? |
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