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The important thing to consider is the chemistry of [carbon dioxide][1] in water, forming [carbonic acid][2]. Note also that [calcium hydroxide][3] is at edge between being a strong or a weak base.
$$\begin{align}\
\ce{CO2 ^ + H2O &<=> CO2 . H2O} \tag{1} \\
\ce{CO2 . H2O &<=> H2CO3} \tag{2} \\
\ce{H2CO3 &<=> H+ + HCO3... |
The important thing to consider is the chemistry of [carbon dioxide][1] in water, forming [carbonic acid][2]. Note also that [calcium hydroxide][3] is at edge between being a strong or a weak base.
$$\begin{align}\
\ce{CO2 ^ + H2O &<=> CO2 . H2O} \tag{1} \\
\ce{CO2 . H2O &<=> H2CO3} \tag{2} \\
\ce{H2CO3 &<=> H+ + HCO3... |
When you heat up a liquid at constant volume (leaving sufficient space for the gas phase), the density of the liquid will decrease and the intermolecular interactions will weaken. Some of the liquid will transition to vapor, so the vapor above the liquid will get denser and the intermolecular interactions will get stro... |
I don't understand how the freezing point of a substance is the same temperature as the melting point of the same substance.
For example, if liquid water freezes at 0 °C how can ice also melts at 0 °C? |
Let us take a mixture of ethanol and acetone as an example. When ethanol is mixed with acetone, the hydrogen bonding between ethanol molecules gets disturbed as actone molecules get in between the ethanol molecules. This results in $\Delta_\text{mix} H\gt0 $ as heat must be supplied to make the solution from its consti... |
Suppose that i have some gas of which the critical temperature is 20°C. Does it mean that how high pressure i apply on the gas, it is not going to turn into a liquid above 20°C? But why so? I think that anything is a liquid if the particles of that substance have got close enough i.e. the space between the particles is... |
When you heat up a liquid at constant volume (leaving sufficient space for the gas phase), the density of the liquid will decrease and the intermolecular interactions will weaken. Some of the liquid will transition to vapor, so the vapor above the liquid will get denser and the frequency of intermolecular interactions ... |
Suppose that I have some substance with a critical temperature of 20°C. That means above that temperature, the substance exists neither as a gas nor a liquid, but instead as a super-critical fluid. Does it mean that no matter how high a pressure I apply on the fluid, it is not going to turn into a liquid above 20°C? Wh... |
What happens when a super-critical fluid is compressed? |
> How much energy is needed to cause 1 mole of H atoms to undergo this transition
**ASSUME BOHR’S MODEL OF QUANTISATION**
The energy for transition is
$$1312(\frac{1}{n_1^2}-\frac{1}{n_2^2})$$
Where the electron moves from n1 to n2
$$1312(1-\frac 19)$$
$$1166.22 KJ/mol$$
The answer given is 1164. I kn... |
Suppose that I have some substance with a critical temperature of 20°C. That means above that temperature, the substance exists neither as a gas nor a liquid, but instead as a super-critical fluid. Does it mean that no matter how high a pressure I apply on the fluid, it is not going to turn into a liquid above 20°C? Wh... |
I've been given the opportunity to use an MP-AES for metal detection. I'm testing traces of metals in plants. The plant matter is digested so I have a liquid solution, I expect there to be a lot of matrix affects within this.
I have tried to use a couple of wavelengths for each metal cadmium, arsenic and lead.
Ars... |
Using MP-AES, can I accurately say I've found a metal concentration on one wavelength and not another? |
I clean vinyl records in an ultrasonic vinyl record cleaning machine the manual states it uses propanol 1-2 diol 178 as a surfactant. I think this is the same chemical as propylene glycol. Is it? Thanks for your help |
Is propanol 1-2 diol 178 the same as propylene glycol? |
> How much energy is needed to cause 1 mole of H atoms to undergo this transition
**Assume Bohr's model of quantisation**
The energy for transition is
$$1312\left(\frac{1}{n_1^2}-\frac{1}{n_2^2}\right)$$
Where the electron moves from $n_1$ to $n_2$.
$$1312\left(1-\frac19\right)$$
$$1166.22\ \mathrm{kJ/mo... |
I know the reduced density matrix has the form:
(,)=⟨Ψ|c†c|Ψ⟩
but when Ψ is the configuration interaction singles (CIS) wavefunction, why are the occupied-virtual (OV) and virtual-occupied (VO) subblocks zero? I see multiple references state that it is due to Brillouins Theorem, but I don't entirely see that con... |
Why are the OV and VO blocks of the CIS 1RDM zero? |
I know the reduced density matrix has the form:
$$
\gamma(\alpha,\beta) = \langle\Psi_N|c^{\dagger}_{\alpha} c_{\beta}|\Psi_n \rangle
$$
but when $\Psi_N$ is the configuration interaction singles (CIS) wavefunction, why are the occupied-virtual (OV) and virtual-occupied (VO) subblocks zero? I see multiple referenc... |
I am working on Ag-Sn-Cu alloy phase diagram to figure out the best temperature / duration to homogenize the alloy (annealing). The %age of elements in the alloy are
1. Ag - 40 %
2. Cu - 27.8 %
3. Sn - 32.2 %
(Composition can be varied if necessary but not more than 5 %)
Now the main goal is:
1. Find out ... |
I have this exercise in my chemistry book, and I have been staring at it for so long but unfortunately I have no single idea what to do and where to start. I will be so thankful for any help.
**$0.05$ moles of NH<sub>3</sub> are added to one liter of MgCl<sub>2</sub> of concentration $0.02$ mol/L.
How many moles of NH... |
What's special about acetone? |
I have an experiment on fats that I have to do in a few hours and I am very lost between fat/oil (lipid) polymerization due to high temperatures and hydrolysis. It appears that both result in the breakdown of fats but in very different ways. Our class assistant suggested to do an experiment about different temperatures... |
I'm trying to set up a gradient calculation for psi4. In my input.dat file, I have tried the following keywords:
```
set basis cc-pVTZ
gradient('CCSD(T)')
```
which is not working. Does anyone have any recommendations on what key words to use at the end of my input file to run a gradient calculation with a CBS?... |
Psi4 gradient calculation with complete basis set? |
I have been tasked with using the one dimensional particle in a box model to calculate the zero point energy of an hydrogen atom with different sizes. Using the formula $E_1=h^2/(8mL^2)$ for a box with length 0.3nm and 1cm I receive results that are very huge, which made me question the validity of my approach.
Is t... |
> Do the particles of thermometer's bulb attain the same translational, rotational and vibrational energy (vibration of atoms within a particle) as of the particles of the liquid?
No, but they will have the same temperature. Solids don't have any translational energy, the atoms time-averaged positions are constant. ... |
The important thing to consider is the chemistry of [carbon dioxide][1] in water, forming [carbonic acid][2]. Note also that [calcium hydroxide][3] is at edge between being a strong or a weak base.
$$\begin{align}\
\ce{CO2 ^ + H2O &<=> CO2 . H2O} \tag{1} \\
\ce{CO2 . H2O &<=> H2CO3} \tag{2} \\
\ce{H2CO3 &<=> H+ + HCO3... |
My Chemistry textbook says this in regard to a C2 molecule:
> It is important to note that double bond
in C2 consists of both pi bonds because of the
presence of four electrons in two pi molecular
orbitals.
Is it possible to account for the double bond in an Oxygen atom consisting of a sigma bond and a pi bond in th... |
Based on Molecular Orbital Theory , how is it decided that the double bond in O2 molecule has one sigma bond and one pi bond? |
[![Diagram picture][1]][1]
[1]: https://i.stack.imgur.com/Vb13F.png
Above is a picture of an alkane. How would I name this using IUPAC rules? I understand how to name other substituents such as (1,1-dimethylethyl) and some other methyl groups, but I don't know how to name the cycloalkane substituents. What ... |
How do I name a substituent which is a cycloalkane which is attached by a chain of more than one carbon? |
Is it a strict rule that when we boil a mixture of two liquids, with one being less volatile than the other, the more volatile vapour has to form the greater portion of the total vapours?
If it is so, how are we able to obtain a pure liquid of less volatility in the distillate and an azeotropic mixture by distilling... |
The more volatile compound forms greater vapour portion, compared to its portion in the distilled liquid.
It forms e.g. 15% molar fraction of vapour, if there is 10% molar fraction in liquid.
In case of deviation from the [Raoult law][1], when there is interaction between compounds, an [azeotrope][2] with minimal (... |
Koopmans' theorem is a useful approach to calculate the global reactivity parameters from the HOMO-LUMO energies. My question is, does it apply to the open-shell systems where we get two sets of singly occupied (alpha and beta) HOMO-LUMO energies? Could anyone help with some literature on the reactivity parameters of o... |
Koopmans' theorem is a useful approach to calculate the global reactivity parameters from the HOMO-LUMO energies. My question is, does it apply to the open-shell systems where we get two sets of singly occupied (alpha and beta) HOMO-LUMO energies? Could anyone help with some literature on the reactivity parameters for ... |
Degrees of freedom describe the different ways atoms move in a sample. For a pure ideal gas made of non-linear molecules, there are 3N degrees of freedom (N is the number of atoms in the molecule), 3N-6 of which are vibrational, 3 rotational and 3 translational. So per atom, we have three degrees of freedom.
How man... |
What are the degrees of freedom in an ionic solid such as sodium azide? |
Degrees of freedom describe the different ways atoms move in a sample. For a pure ideal gas made of non-linear molecules, there are 3N degrees of freedom (N is the number of atoms in the molecule), 3N-6 of which are vibrational, 3 rotational and 3 translational. So per atom, we have three degrees of freedom.
How man... |
the question was:
the correct iupac name of the following compound is :
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/kQQKa.png
(a) 2,4,6-trimethyl cyclohexanone
(B) 1,3,5- trimethyl benzophenone
(c) trimethylcyclobutanone
(d) 2,4,6-trimethylcyclohexanone
I was confu... |
is space in between has any significance in IUPAC nomenclature? |
> The correct IUPAC name of the following compound is:
> [![enter image description here][1]][1]
> (**a**) 2,4,6-trimethyl cyclohexanone
> (**b**) 1,3,5- trimethyl benzophenone
> (**c**) trimethylcyclobutanone
> (**d**) 2,4,6-trimethylcyclohexanone
I was confused between option (**a**) and (**d**). I ... |
Does space in between have any significance in IUPAC nomenclature? |
I know that an ether with a 3° alkyl group and a 1° alkyl group is cleaved by $\mathrm{S_N1}$ mechanism to give a tertiary alkyl halide and a 1° alcohol.
And an ether with a two 1° alkyl groups is cleaved by $\mathrm{S_N2}$ mechanism to give a 1° alkyl halide and a 1° alcohol.
But what happens if a ether with a 2... |
All the atoms of these compounds are in a plane.
*o*-phthalic acid can show extensive intra-molecular hydrogen bonding as well as inter-molecular hydrogen bonding.
*m*-phthalic acid can show intra-molecular hydrogen bonding (though, in lesser extent) as well as inter-molecular hydrogen bonding.
*p*-phthalic ac... |
> **49.** How many enolizable hydrogens are there in the following compound?
> [![2‐methylcyclohex‐2‐en‐1‐one][1]][1]
> (**a**) 2
> (**b**) 4
> (**c**) 5
> (**d**) 7
I know that enolate ion is the anion formed when an α-hydrogen in the molecule of an aldehyde or ketone is removed as a hydrogen ion.
... |
How there are 7 enolizable hydrogens in 2‐methylcyclohex‐2‐en‐1‐one? |
As the title says it, I am curious about why the sample (ie, an extract of plant's chlorphyl transferred onto paper) must not be dipped into the mobile phase (ie, the solvent which goes up the paper)?
My first guesses are that it is because the sample would dissolve into the solvent and only a small portion of the s... |
Why mustn't the sample be dipped in the mobile phase in paper chromatography? |
> The temperature at which NOx is in equilibrium with its liquid and vapor phase at 1 atm is about –84 °C. Does that mean NOx exists as a liquid at that temperature? What about it's vapor phase then, because it's vapor and liquid phase should be at equilibrium, right?
Yes, the vapor and liquid can coexist, provided ... |
> The temperature at which NOx is in equilibrium with its liquid and vapor phase at 1 atm is about –84 °C. Does that mean NOx exists as a liquid at that temperature? What about it's vapor phase then, because it's vapor and liquid phase should be at equilibrium, right?
Yes, the vapor and liquid can coexist, provided ... |
A hydrogen bond is formed between hydrogen attached to highly electronegative atoms (nitrogen, oxygen, and fluorine) which are small in size too and the non-bonding pair of electrons of another such atom that may be present in the same molecule or in another molecule but is not directly linked to it with a covalent bon... |
What is a caulk (or bonding adhesive) that can be exposed permanently submerged in an isopropyl alcohol (>91%) bath?
The idea came from this previous question:
https://chemistry.stackexchange.com/questions/33909/silicone-vs-alcohol
It seems from one of the answers there the alcohol would be resistant but the adh... |
What is an example of an isopropyl alcohol resistant caulk? |
How does acetone help to make a liquid cleaner stronger? |
Not an answer, but a strategy to get one: You could try googling 'alcohol-resistant caulk' or 'alcohol-resistant sealant'. This will give you hits for chemical companies that produce such products. For instance,
https://www.azom.com/article.aspx?ArticleID=5854
claims to have an epoxy ("UV18MED") that is alcohol-... |
Not an answer, but a strategy to get one: I would start by googling 'alcohol-resistant caulk' or 'alcohol-resistant sealant'. This will give you hits for chemical companies that produce such products. For instance,
https://www.azom.com/article.aspx?ArticleID=5854
claims to have an epoxy ("UV18MED") that is alcoh... |
Not an answer, but a strategy to get one: I would start by googling 'alcohol-resistant caulk' or 'alcohol-resistant sealant'. This will give you hits for chemical companies that produce such products. For instance,
https://www.azom.com/article.aspx?ArticleID=5854
claims to have an epoxy ("UV18MED") that is alcoh... |
The more volatile compound forms greater vapour portion, compared to its portion in the distilled liquid.
It forms e.g. 15% molar fraction of vapour, if there is 10% molar fraction in liquid.
In case of deviation from the [Raoult law][1], when there is interaction between compounds, an [azeotrope][2] with minimal (... |
I was preparing $\rm Mn_3O_4$ but it was when characterized by XRD, a $\rm Mn_2O_3$ phase existed. Now how can I convert $\rm Mn_2O_3$ to $\rm Mn_3O_4$? |
How to convert $\rm{Mn_2O_3}$ to $\rm Mn_3O_4$? |
You may need a good lab oven.
[Manganese(II,III) oxide on Wikipedia][1]
> **Preparation**
> Mn3O4 formed when any manganese oxide is heated in air above 1000 °C. Considerable research has centred on producing nanocrystalline Mn3O4 and various syntheses that involve oxidation of MnII or reduction of MnVI.
[1]:... |
I was preparing $\ce{Mn3O4}$ but it was when characterized by XRD, a $\ce{Mn2O3}$ phase existed. Now how can I convert $\ce{Mn2O3}$ to $\ce{Mn3O4}$? |
How to convert Mn2O3 to Mn3O4? |
I know how to predict magnetic nature when the compound contains only strong field or only weak field ligands. But in [Co(NH3)4Cl2]Cl, NH3 is a strong ligand whereas Cl is a weak ligand. So how do we know if the ligands are causing the electrons to pair up or not? I understand VBT and CFT to predict the hybridisation a... |
I know how to predict magnetic nature when the compound contains only strong field or only weak field ligands. But in $\ce{[Co(NH3)4Cl2]Cl},$ $\ce{NH3}$ is a strong ligand whereas $\ce{Cl-}$ is a weak ligand.
So, how do we know if the ligands are causing the electrons to pair up or not? I understand VBT and CFT to p... |
Copper has two chlorides: $\ce{CuCl2}$ and $\ce{CuCl}.$
Copper reacts directly with chlorine to form a copper(II) chloride. Why doesn't it form copper(I) chloride? Is it because $\ce{CuCl2}$ is more stable than $\ce{CuCl}?$ I want a more foundational approach to answer this question. |
Yep, it has to do with the orbitals.
$\ce{CO2}$ is linear, so even though the $\ce{C-O}$ bonds have individual dipole moments, the overall dipole moment is zero as these cancel out (they point in opposite directions, as shown in the diagram below).
On the other hand, $\ce{H2O}$ is "bent", which means that the ind... |
Why the given reaction show allylic shift? |
In the following reaction
[![Reaction between 2‐methylbut‐3‐en‐2‐ol and hydrogen bromide][1]][1]
shouldn't the minor product be the major one as the carbocation formed before attachment of bromine is 3°? Also, can someone tell me why the product includes only nucleophilic substitution as there is no other conditi... |
Why does the reaction between 2‐methylbut‐3‐en‐2‐ol and hydrogen bromide show allylic shift? |
I am electrolysing water using several different potential catalysts for my eight grade science fair project. The electrolysis will be running at 2 to 2.5
volts over nickel electrodes, as I do not need a long term solution. How much amperage should I put on my DC power supply? Thanks and I would appreciate simplified ... |
Amperage for electrolysis of water? |
I am electrolysing water using several different potential catalysts for my eight grade science fair project. The electrolysis will be running at 2 to 2.5
volts over nickel electrodes, as I do not need a long term solution. How much amperage should I put on my DC power supply? Thanks and I would appreciate simplified ... |
Is it possible for the kinetic-energy integral, Tij, to be negative? I was messing around with some HF code and found that the integral became negative on some off-diagonal terms. (This could also be a bug with the code.)
If the kinetic energy integral is negative, what would the physical meaning be? |
Is it possible for the kinetic energy integral to be negative? |
In electrochemistry, the rate of electrolysis depends on rate of charge entering the cell. Second most important point is that one either control potential or current but *not both* during electrolysis i.e. you cannot have both values set. If you are fixing potential at 2.5 V, the value of current is not in your hand. ... |
In electrochemistry, the rate of electrolysis depends on rate of charge entering the cell. Second most important point is that one can either control potential or current but *not both* during electrolysis i.e. you cannot have both values set. If you are fixing potential at 2.5 V, the value of current is not in your ha... |
Gallium can make aluminum [soft and brittle][1] as long as it bypasses the aluminum oxide normally formed on the surface of the aluminum (for example by scratching the surface).
Mercury can [weaken aluminum][2] as well.
Are there any other metals or alloys that can be "weakened" by coming in contact with gall... |
Gallium makes aluminum soft like a wet tissue. Any other metals or alloys that are vulnerable to similar damage? |
Amperage for the electrolysis of water? |
This sounds like a stupid question perhaps, but if a stream of pure O2 was directed at the flame as a concentrated jet would it blow off the candle? |
Is it possible to blow out a candle flame using pure oxygen? |
Gallium can make aluminum [soft and brittle][1] as long as it bypasses the aluminum oxide normally formed on the surface of the aluminum (for example by scratching the surface).
Mercury can [weaken aluminum][2] as well.
Are there any other metals or alloys that can be "weakened" **by coming in contact** with ... |
I've recently carried out an experiment trying to measure the boiling point elevation of water after adding 5M of NaCl and KCl. Although for some reason, KCl solution started boiling around 90 degree Celsius, theoretically, both KCl and NaCl should have the same effect on the boiling point of water right? |
Boiling point elevation does not depend on the solute? |
How to determine the pH of a mixture of two weak acids? |
> Which element has the greatest electrical conductivity?
>*(A)* $\ce{As}$
>*(B)* $\ce{Ge}$
>*(C)* $\ce{P}$
>*(D)* $\ce{Sn}$
I am unsure of how to approach this problem. Is there some sort of trend for electrical conductivity or some other method to determine which of these answers the question?
I am ... |
Are there any trends for electrical conductivity? |
Mgnesium can do a redox reaction with $\ce{Cu^2+}$ as well as with $\ce{Zn^2+}$, since Mg has the lowest reduction potential $E_0$. (I am aware that a reaction may or may not be feasible as redox, and this is according the reduction potential of the two half-equations)
\begin{array}{l|l|r}
\ce{Cu^2+ & Cu} &\pu{0.34... |
Will magnesium undergo a redox reaction with zinc(II) or copper(II)? |
Magnesium can do a redox reaction with $\ce{Cu^2+}$ as well as with $\ce{Zn^2+}$, since Mg has the lowest reduction potential $E_0$. (I am aware that a reaction may or may not be feasible as redox, and this is according the reduction potential of the two half-equations)
\begin{array}{l|l|r}
\ce{Cu^2+ & Cu} &\pu{0.3... |
>Find the heat that will be released in kJ per gram when aluminium ($\ce{Al}$) reacts with $\ce{Fe2O3}$ as follows:
$$\ce{2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(l)}$$
The information given is:
- $\Delta H = 12.40 \space \rm{kJ/mol}$ (for $\ce{Fe}$)
- $\Delta H = -822.2 \space \rm{kJ/mol}$ (for $\ce{Fe2O3}$)
- $... |
According to [LabChem](http://www.labchem.com/products/online-catalog/browse-products/sulfuric-acid-72-w-w-24n-12m.html), $12~\mathrm{M}$ of $\ce{H2SO4}$ is $72~\mathrm{w/w\%}$.
When I try to convert $12~\mathrm{M}$ of $\ce{H2SO4}$ to $\mathrm{w/w\%}$ I get $117\%$ which is obviously wrong.
$$\begin{multline}
1... |
How is sulfuric acid with a concentration of 12 M also 72% w/w? |
> What is the amount of nitrate ions in $20.0\:\mathrm{g}$ of $\ce{Fe(NO3)3}$?
The chemical formula for the nitrate ion is $\ce{NO3}$, I think.
The molar mass of $\ce{Fe(NO3)3}$ is $242~\mathrm{g~mol^{-1}}$ of which $186\ \mathrm{g\ mol^{-1}}$ belong to $\ce{NO3}$. That means that around $76.85\:\%$ of the substa... |
Recently I ran out of dish washing detergent, so I decided to pick up one of the recepis online, to make my own "ecological" dish washing detergent alternative.
[The recipe was][1]:
1. Mix ingridients:
1. 400ml of water
2. 200mg of kitchen salt
3. 100ml of vinegar
4. juice squeezed from 3 lemons... |
Why my boiling pot turned black? |
Recently I ran out of dish washing detergent, so I decided to pick up one of the recepis online, to make my own "ecological" dish washing detergent alternative.
[The recipe was][1]:
1. Mix ingridients:
1. 400ml of water
2. 200mg of kitchen salt
3. 100ml of vinegar
4. juice squeezed from 3 lemons... |
Recently I ran out of dish washing detergent, so I decided to pick up one of the recipes online, to make my own "ecological" dish washing detergent alternative.
[The recipe was][1]:
1. Mix ingredients:
1. 400ml of water
2. 200mg of kitchen salt
3. 100ml of vinegar
4. juice squeezed from 3 lemons... |
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