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Which of the following statements is true?
$11.2$$ dm^{3}$ of Nitrogen at STP
A: has a mass of $14 $g.
B: consists of $0,5$ mol atoms.
My instinct was that the answer is $B$ because any gas has a volume of $22.4$ liters regardless of what the gas is. If $0.5$ mol of Nitrogen weights $11.2~\mathrm{dm^{3}}$ a... |
Does 11.2 dm3 of nitrogen consist of 0.5 moles at STP? |
Which of the following statements is true?
$11.2$$ dm^{3}$ of Nitrogen at STP
A: has a mass of $14 $g.
B: consists of $0,5$ mol atoms.
My instinct was that the answer is $B$ because any gas has a volume of $22.4$ liters regardless of what the gas is. If $0.5$ mol of Nitrogen weights $11.2~\mathrm{dm^{3}}$ a... |
Does 11.2 dm3 of nitrogen consist of 0.5 moles at STP? |
Which of the following statements is true?
$11.2~\mathrm{dm^{3}}$ of Nitrogen at STP
A: has a mass of $14 $g.
B: consists of $0,5$ mol atoms.
My instinct was that the answer is $B$ because any gas has a volume of $22.4$ liters regardless of what the gas is. If $0.5~\mathrm{mol}$ of Nitrogen weights $11.2~\m... |
$\Delta G = -n {\mathcal F} \Delta {\mathcal E} $
$\mathcal F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and tim... |
The [broad absorption bands][1] of the electronic transitions observed in UV/Vis spectroscopy/spectrophotometry, as well as the myriad types of electronic transitions that might lead to absorption at a given wavelength, indeed make the technique much less powerful for identification of unknown compounds as compared to,... |
The [broad absorption bands][1] of the electronic transitions observed in UV/Vis spectroscopy/spectrophotometry, as well as the myriad types of electronic transitions that might lead to absorption at a given wavelength, indeed make the technique much less powerful for identification of unknown compounds as compared to,... |
I studied bohrs model of atom and then the drawbacks of it and then wuantum mechanical model of atom. Now quantum model is according to uncertainty principal and dual nature of matter and it says we can not talk about fixed orbits (uncertaity principle) and can only talk of an area of maximum probability of finding an... |
I studied Bohr's model of atom and then the drawbacks of it and then quantum mechanical model of atom. Now quantum model is according to uncertainty principal and dual nature of matter and it says we can not talk about fixed orbits (uncertainty principle) and can only talk of an area of maximum probability of finding ... |
![Claisen condensation mechanism][1]
[1]: https://i.stack.imgur.com/nomq9.png
Aren't two last steps superfluous? I just do not see how the fourth and last forms differ. |
I tried to draw the frontier orbitals of the biradical structure:
![enter image description here][1]
(A) At the top I've drawn the HOMO and LUMO, because I know that the reaction coordinate belongs to the $\ce{C_{$2v$}}$ point group. These two orbitals of the HOMO (green) lies in the O-C-O plane. In each $p$ orbi... |
Are the p orbitals of the biradical dioxo compound in the HOMO perpendicular to the plane? |
> So how come we are talking about fixed shells again and returning to
> what Bohr said?
Nope, we are not returning to the [old quantum theory][1]. We do not talk about orbits anymore, but we rather have *orbitals*. Note that it is important to bear in mind that orbitals also *aren't real*, that this description is... |
In a nearly finished bowl of oat cereal, why do the pieces of cereal stick together? I figure that since they are composed of starches it could be hydrogen bonding. Is this true or is there some other reason? |
Okay, enough commenting! Let's piece it together.
Upon adding $\ce{SO2}$ gas to water, it shows its *acidic oxide* character by hydrolyzing to sulfurous acid:
$$\ce{SO2(g) + H2O(l) <=> H2SO3(aq)}$$
$\ce{H2SO3}$ is a **weak** diprotic acid in water, with the following acid dissociation equilibria:
$$\ce{H2SO... |
I tried to draw the frontier molecular orbitals of the following biradical structure:
![enter image description here][1]
(A) At the top I've drawn the HOMO and LUMO, because I know that the reaction coordinate belongs to the $\ce{C_{$2v$}}$ point group. These two orbitals of the HOMO (green) lies in the O-C-O pla... |
it has been defined as the energy avaliable for work other than expansion work. why can't it be used for expansion work? i think i'm missing something here |
regarding Gibbs's function, why is is non-expansion work? |
Have P-acyl phosphines ever been synthesized? |
It has been defined as the energy available for work other than expansion work. Why can't it be used for expansion work? I think I'm missing something here |
Regarding Gibbs's function, why is is non-expansion work? |
- *Is it true that precipitates dissolve upon addition of diluted acids*?
- *If a precipitates is dissolve , does it disappear from solution , or any thing else happened out there?*
I am just curious about this. Because I have heard that **precipitates can be dissolved** if you add a diluted acid. But why i... |
Can a precipitate dissolve upon addition of a diluted acid? |
Two chemicals are used in [lead test kits][1]: sodium sulfide or a rhodizonate salt. [Sodium sulfide][2] should be easy to obtain (or synthesize), and is useful for light-colored paint, as it produces a gray or black color change. [Potassium rhodizonate][3] can be synthesized from inositol, but you might be better off ... |
Which of the following statements is true?
$11.2~\mathrm{dm^{3}}$ of Nitrogen at STP
A: has a mass of $14 $g.
B: consists of $0,5$ mol atoms.
My instinct was that the answer is $B$ because any gas has a volume of $22.4$ liters regardless of what the gas is. If $0.5~\mathrm{mol}$ of Nitrogen has a volume of ... |
We've learnt about the trans effect but I have a question regarding how this plays a role with water in the equation.
**trans-effect**:
H2O < NH3 < Cl2
Based on this, given *cis*-[Pt(NH3)2Cl2], if you were to add water to form a dicationic complex, would a substituion reaction occur between all the substituent... |
We've learnt about the trans effect but I have a question regarding how this plays a role with water in the equation.
**trans-effect**:
$$\ce{H2O < NH3 < Cl2}$$
Based on this, given *cis*-$\ce{[Pt(NH3)2Cl2]}$, if you were to add water to form a dicationic complex, would a substituion reaction occur between all... |
I am preparing to do a vacuum distillation and am unsure exactly how to manage the vacuum. The vacuum pump I have is a two-stage rotary vane pump which is capable of 250 microns or lower. It has a triple inlet, one 1/4", 3/8" and 1/2".
My glassware is typical distillation glassware including a Graham condenser and a... |
*The correct answer for this question is* **A**
*Prior to start explaining the answer for your question, I would like to show you a mistake you have done.
You have said*
>"**any gas has a volume of 22.4 litres regardless of what the gas is.**"
*This true only if the gas exist in standard temperature and pres... |
Is there a maximum optical rotation of plane polarized light that can be observed using a polarimeter?
I understand that in a polarimeter, light passes through a filter that converts it into plane polarized light. This type of light only oscillates in one plane. When it is passed through an optically active solution, ... |
I am interested in the chemical lsd or "acid". I wanted to know if lsd is acid in its pure form would that mean it is water? |
Ph of acid would be one? |
>I am not sure I should continue on sulfuric acid and potassium parmagnet test in a TEST TUBE after seeing this affect...
In case of doubt you should not. Anyway, I recommend to avoid doing it with any significant amount. It may and will spread around and even if not it produces manganese (IV) oxide smoke that settl... |
The universe cooled after the Big Bang. There was certainly an epoch when the universe’s overall temperature decreased from 200 °C to −40 °C throughout a *very* large volume. There is your test tube (more like a Florence flask) for abiogenesis and then the panspermia reservoir.
Before you suspect the preceding is cl... |
Is there a maximum optical rotation of plane polarized light that can be observed using a polarimeter?
I understand that in a polarimeter, light passes through a filter that converts it into plane polarized light. This type of light only oscillates in one plane. When it is passed through an optically active solution, ... |
Regarding Gibbs's function, why is there non-expansion work? |
When it gets to Carbon-based molecules, one very possible structure when there are more than six C atoms is the hexagon; though not mostly perfect, it emphasizes that six Carbon atoms tend to bond with each other.<sup>`*`</sup> Why? <br/>
I assume this is because of the <em>"stability"</em> that is attributed to the h... |
Suppose I have the reversible reaction:
$$\ce{A +B⇌ C} $$
The reaction is at equilibrium with equilibrium constant $K$
I am told that if I increase the concentration of $\ce{B}$, the rate for the forwards reaction will exceed the backwards one. Fair enough.
I am also told that $K$ will necessarily increase... |
Is it possible to make a solution of ph 7 phosphate buffer solution using phosphoric acid and $\ce{K2HPO4}$ ? How can I calculate the amount of $\ce{K2HPO4}$ needed for 1L of phosphoric acid ?
Edit:
I have 50 mL of 0.2M $\ce{H3PO4}$ solution. How can I convert this solution into 50 mL of pH 7 buffer solution by a... |
Phosphate buffer from phosphoric acid and K2HPO4? |
Why does a dissociation reaction increases with the addition of an inert gas?
I am still new to the topic equilibrium so please explain in simple words. |
I read this question (http://chemistry.stackexchange.com/questions/5202/flame-temperature-for-cooking-food) and came up with the following questions:
- Could companies color their flames so that products would heat quicker?
- How would they do this?
- Could you use this to make an infrared or ultraviolet fla... |
Can you color a flame and what would the effects be? |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice it's pretty much unnecessary.
It's very important to distinguish two types o... |
How can shorter bonds between $\ce{C-H}$ be easier to break than longer ones?
For example, consider the length of the $\ce{C-H}$ bonds in ethane, ethene and ethyne, and the corresponding acidities.
Ethane: BL = 1.102 Å; $\mathrm{p}K_\mathrm{a} = 50$
Ethene: BL = 1.085 Å; $\mathrm{p}K_\mathrm{a} = 44$
Ethyne: ... |
How to find the valencies of elements by using its distribution of electrons?
Please explain the method in simple words. Do you have to study the valencies or is there a simple way of remembering?
PS: There is supposed to be some method of getting the valency after knowing the distribution of electrons. For example... |
I need to etch small PCB for my project, since I do this once in a blue moon I would like to try some easy approach, preferably with household items. I'm aiming at the use of acetic acid with hydrogen peroxide to aid the reaction. But this got me wondering what are some other household items usable in the process?
I... |
Alternative PCB etching solutions - Is KMnO4 or NaClO suitable oxidizer? |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice it's pretty much unnecessary.
It's very important to distinguish two types o... |
We have pseudo-asymmetric carbons in optical isomerism which dictates that if 2 groups on the carbon atom are different in terms in configuration then the carbon is chiral. In alkenes can the same thing happen with respect to geometrical isomerism? For example consider ![enter image description here][1]
If both the ... |
I want to know how to typeset character tables of point groups correctly. Consider the following two extremes using the $C_{\text{2v}}$ (or is it $\text{C}_{\text{2v}}$?) point group as an example.
Firstly, one where all the symbols (except for the symbols denoting vertical) are cursive (your default LaTeX math mode... |
How are point group character tables typeset correctly? |
I'm trying to calculate the energy required to dissociate a single $\ce{CO2}$ molecule into its respective elements, and I'm given that it takes $ 373.6 \times 10^{3} \, \, \mathrm{\frac{joules}{gram}} $ where $44.01$ grams is the mass of $6.022 \times 10^{23}$ molecules of $\ce{CO2}$.
By dimensional analysis:
... |
Is there a heat capacity of an object when it is melting?
I’m questioning it since the temperature doesn’t change during phase transitions and the unit of heat capacity is joule per kelvin. |
Calculate the $\ce{pH}$ of a $100$ $\ce{mL}$ solution containing $0$$.0375$ moles of the weak base, Sodium Benzoate, $\ce{C6H5COONa}$.
> $$\ce{C6H5COO + H2O -> C6H6COO- + OH-}$$
$$\frac{0.0375 ~\mathrm{mol}}{.100~ \mathrm{L}} = 0.375~M$$
$$\ce{pOH} = 0.43$$
$$\ce{pH} = 13.57$$
Is this right? Thank you. |
My professor told us the following:
> $\ce{NaHCO3}$ will react to evolve
> $\ce{CO2}$ whenever the acidic nature of the reactant exceeds the
> acidic nature of benzoic acid.
I want to know why this is. And is the given statement valid? He didn't give us the reason. And in that case should $\ce{NaHCO3}$ react ... |
I already know the way to determine ,if the given reaction is exothermic or endothermic by the enthalpy values .But is it possible without enthalpy values, and just by looking at the reaction?
So as far as I know there are two types of chemical reactions , namely one way reactions and reversible reactions.
-So ... |
How can I figure out whether a reaction is endothermic or exothermic without it's enthalpy value? |
I already know the way to determine, if the given reaction is exothermic or endothermic, by the enthalpy values. But is it possible without enthalpy values, and just by looking at the reaction?
So as far as I know there are two types of chemical reactions, namely one way reactions and reversible reactions.
So ho... |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
Is there a maximum optical rotation of plane polarized light that can be observed using a polarimeter?
I understand that in a polarimeter, light passes through a filter that converts it into plane polarized light. This type of light only oscillates in one plane. When it is passed through an optically active solution... |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
Its really interesting to see the process of recycling of paper (as shown in picture below) but at the same time I was thinking like for how many times can one sheet of paper can be recycled ?
![enter image description here][1]
[1]: https://i.stack.imgur.com/rUa0k.jpg |
Is the following molecule aromatic??
![molecule][1]
[1]: https://i.stack.imgur.com/8yX6X.png |
Is the following molecule aromatic? |
Which of the following statements is true?
$11.2~\mathrm{dm^{3}}$ of nitrogen at STP
A: has a mass of $14\ \mathrm{g}$.
B: consists of $0.5\ \mathrm{mol}$ atoms.
My instinct was that the answer is B because any gas has a volume of $22.4$ liters regardless of what the gas is. If $0.5~\mathrm{mol}$ of nitroge... |
I already know the way to determine whether if the given reaction is exothermic or endothermic by the enthalpy values. But is it possible without enthalpy values, and just by looking at the reaction?
So as far as I know there are two types of chemical reactions, namely one way reactions and reversible reactions.
... |
How can I figure out whether a reaction is endothermic or exothermic without its enthalpy value? |
Is the following molecule aromatic??
![molecule][1]
[1]: https://i.stack.imgur.com/8yX6X.png
It does seem like it will be aromatic because it is similar to furan. I am confused because of the positive charge on the $\ce{N}$. |
What I thought was that graphite has van der Waals forces while diamond has covalent forces so diamond should be more stable. But the melting point of graphite is more than diamond which implies that it is thermodynamically more stable. I am thoroughly confused. So which is more stable? |
The change in enthalpy of carbon in diamond form to graphite is negative. This suggests that graphite should be more stable than diamond. Is it true? |
How do I calculate the temperature of hot air in kelvin? |
This is something I discovered after an attempt at a more mathematically rigorous investigation of how to interpret polarimetry results. It's not that hard, but I don't think you'll ever find a similar analysis in a book because in practice the details are pretty much unnecessary for experimental purposes (though fun m... |
Is the following molecule aromatic?
![molecule][1]
[1]: https://i.stack.imgur.com/8yX6X.png
It does seem like it will be aromatic because it is similar to furan. I am confused because of the positive charge on the $\ce{N}$. |
**It is all about minimizing the energy of a molecule.**
In the case of carbon, the only molecule that adopts a perfect hexagonal geometry in its ground state is benzene (and its derivatives that possess a 6-fold rotational axis). In this case the hexagonal geometry is adopted because all of the carbons are $\ce{sp... |
I know that the polyethylene's melting point is between 115–135 °C, however I would like to know that can it start dissolving between 50-60 °C?
In a real example, if I put warm food (straight from the oven, I think it can be max. 50-60 °C) into re-closable polyethylene plastic bag and close it, will any chemical re... |
I couldn't find a source that explicitly say this, but given the gas constant R is used, is the Arrhenius equation only valid when all reactants are gases? Do they have to be ideal gases?
If the above is true, is there a similar equation for reactions where at least one reactant is in liquid/solid form? |
Is the Arrhenius Equation valid for when reactants are in gas/vapour state? |
I won this ["toy"](http://www.amazon.com/OWI-Salt-Water-Monster-Truck/dp/B007V5TEMW/ref=sr_1_fkmr1_1?ie=UTF8&qid=1434318147&sr=8-1-fkmr1&keywords=inpro+solar+car+salt+water) at a science fair...
Now I have to make a short presentation about it in school.
On the package description they describe its energy source as ... |
Is this product description wrong and a simple battery and not a fuel cell? |
Is the Arrhenius Equation only valid for reactants in the gas state? |
The correct answer for this question is **A**
Prior to start explaining the answer for your question, I would like to show you a mistake you have done.
You have said
>"**any gas has a volume of 22.4 litres regardless of what the gas is.**"
This true only if the gas exist in standard temperature and pressure ... |
I know that polyethylene's melting point is between 115–135 °C, however I would like to know if can it start dissolving between 50-60 °C?
In a real example, if I put warm food (straight from the oven, I think it can be max. 50-60 °C) into a re-closable polyethylene plastic bag and close it, will any chemical reacti... |
Though polyethylene (polythene in the UK) food bags and containers are *quite safe to use* even with hot food, oils, fats and other materials *do* penetrate polyethylene. For example, [lycopene][1] in tomato sauce or paste is absorbed so that the container is stained orange in a few days at room temperature, or in minu... |
The correct answer for this question is **A**
Prior to start explaining the answer for your question, I would like to show you a mistake you have done.
You have said
>"**any gas has a volume of 22.4 litres regardless of what the gas is.**"
This true only if the gas exist in standard temperature and pressure ... |
The classic paper of Dr. Norskov (https://profiles.stanford.edu/jens-noerskov) explained this phenomenon very well. (Off topic: Dr. Norskov is like the godfather of catalysis and I had a chance to meet him at a summer school and that was a great experience for me.
The inertness of metal surface to adsorb depends on... |
The correct answer for this question is **A**
Prior to start explaining the answer for your question, I would like to show you a mistake you have done.
You have said
>"**any gas has a volume of 22.4 litres regardless of what the gas is.**"
This true only if the gas exist in standard temperature and pressure ... |
$\Delta G = -n {\mathcal F} \Delta {\mathcal E} $
$\mathcal F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and tim... |
Let's consider the following redox couples:
$\ce{Cu^{2+} + e^- ->Cu^+\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}{ E^o_1}(\ce{Cu^{2+}/Cu^+}=0.17\, \ce{V})$
$\ce{Cu^{2+} + e^- + I^- ->CuI\,\,\,\,\,\,\,\,\,\,\,\,}{ E^o_2}(\ce{Cu^{2+}/CuI}=?)$
As the chemical species $\ce{Cu^{2+}}$, $\ce{Cu^+}$ and $\ce{CuI... |
Okay, let me give you the screen shot of this doubtful question.
![enter image description here][1]
**I got the answer for the Roman number 1,here is the way I did it,**
- Since they have given the pH ,I did found the $[H^+(aq)]$
$pH=-log[H^+(aq)]$
$ [H^+(aq)]= 10^{-3.21}$ = $6.16 $ x $10^{-4} mol... |
A doubt on phase equilibrium? |
Given a mixture of $\ce{HCl}$ and $\ce{MCl3}$ and the following dissociation constants for $\ce{M(OH)3}$, how can the concentrations of $\ce{HCl}$ and $\ce{MCl3}$ be determined separately by titrating this solution with a standard strong base (say, $0.1\:\mathrm{M}$ $\ce{NaOH}$) ? I want to be able to sketch the approx... |
Who devised term elements? Who was the one who brought the term elements to us.Also please give a bit information on background of the man. |
Who devised term elements? |
Who devised the term elements? Who was the one who brought the term elements to us? Also please give a bit information on background of the man. |
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