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I’m required to make a lab with this information only (particle size vs dissolving rate of a solid (molecular covalent compound-sucrose)? so far what I’m thinking is using three different kinds of sugar like table sugar, sugar cubes, and one of them grinding it but the issues is how do you find how they dissolving rate...
In the preparation of $\ce{NH3}$ from $\ce{NH4Cl}$ and $\ce{Ba(OH)2}$, my teacher said that when heating the test tube, the test tube faces downwards as opposed to upwards. Why is this so? Wouldn't the solid just fall out? [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/AvEVU.png
Why does the test tube face downwards in gas production?
The percent of Ethyl Alcohol in hand sanitizers slowly drops over time. And manufacturers put an expiration date on the bottles. But I'd to test the percent of Ethyl Alcohol for myself for a new bottle and to see how much over time is lost as it gets close to the expiration data and beyond. Is this possible for a chemi...
Possbile to test percent of Ethyl Alcohol in hand sanitizer?
I experimented $\ce{CO2}$ generation by adding $\pu{4 g}$ of $25\%$ acetic acid water solution ($= \pu{1 g}$ of acetic acid) to $\pu{1.4 g}$ of pure baking soda. But this mixture yielded only $50\%$ less than the calculated amount $\pu{373 mL}$ of $\ce{CO2}$. $$ M(\ce{CH3COOH}) = \pu{60g/mol}, M(\ce{NaHCO3}) = \pu...
Why does vinegar and baking soda yield a far smaller volume of carbon dioxide gas than expected from calculation?
I want to ask a question about the shoulders of peaks when separating overlapping peaks. I have the following spectrum circled with relevant shoulders: [![NMR Peak][1]][1] I believe that the spectrum above shows an overlapping triplet and doublet, but I want to know what causes these shoulders in the NMR spec...
I've noticed that in the mass spectrum of 3-chloropropene, there is a peak at m/z = 39, which to me, indicates the formation of the C3H2 ion. However, given that 3 bonds would have to be broken to form this ion, how can the frequency of this cleavage be explained? [![enter image description here][1]][1] ...
I want to ask a question about the shoulders of peaks when separating overlapping peaks. I have the following spectrum circled with relevant shoulders: [![NMR Peak][1]][1] I believe that the spectrum above shows an overlapping triplet and doublet, but I want to know what causes these shoulders in the NMR spec...
I've noticed that in the mass spectrum of 3-chloropropene, there is a peak at m/z = 39, which to me, indicates the formation of the C3H3 ion. However, given that 3 bonds would have to be broken to form this ion, how can the frequency of this cleavage be explained? [![enter image description here][1]][1] ...
I am trying to make my own hand sanitiser since it’s sold out everywhere. The formular I use is 1 part aloe vera gel, 2 parts 100% isopropyl alcohol. The problem is when mixing the 2, the solution always forms a small white spongy sticky substance while the rest stays liquid, not gel like: [![enter image description...
As we all know, adding salt to ice water lowers its temperature. I've read plenty of system-level accounts of energy balances, enthalpies, vapor pressures, phase equilibria and freezing points—I understand that chemists' bread and butter is doing energy arithmetic on thermodynamic systems as a whole, but I would lik...
**Water loses kinetic energy when it detaches from the surface of the ice** Water molecule in the solid phase have more hydrogen bonds than in the liquid phase. It takes energy to break these bonds, so only molecules with sufficient kinetic energy will detach (maybe because they just collided with a water molecule t...
$\Delta H$ is temperature-dependent, pressure-dependent, and concentration-dependent, so it's certainly theoretically possible for it to change sign in a chemical reaction as a result of changes in any of these intensive properties. NIST has a detailed Shomate Equation that has been experimentally verified to mode...
Yes, because $\Delta H$ is temperature-, pressure-, and concentration-dependent, there exist chemical reactions, and physical changes, in which its sign reverses as a result of changes in these intensive properties. NIST has a detailed Shomate Equation that has been experimentally verified to model the standard* hea...
Research has recently found that FeOOH is 25 times better at hydrogen production than titanium dioxide. Today, a new electrolysis plant today delivers energy efficiency of around 80%. Is 25x the Honda-Fujishima reaction, using FeOOH higher efficiency than that? ref: https://www.tus.ac.jp/en/mediarelations/archi...
Efficiency of H production from FeOOH catalist?
I am trying to make my own hand sanitiser since it’s sold out everywhere. The formular I use is 1 part aloe vera gel, 2 parts 100% isopropyl alcohol. The problem is when mixing the 2, the solution always forms a small white spongy sticky substance while the rest stays liquid, not gel like: [![enter image description...
I am trying to make my own hand sanitiser since it’s sold out everywhere. The formula I use is 1 part aloe vera gel in 2 parts 100% isopropyl alcohol. The problem is when mixing the two, the solution always forms a small white spongy sticky substance while the rest stays liquid, not gel like: [![container holding gr...
I am trying to make my own hand sanitiser since it’s sold out everywhere. The formula I use is 1 part aloe vera gel in 2 parts 100% isopropyl alcohol. The problem is when mixing the two, the solution always forms a small white spongy sticky substance while the rest stays liquid, not gel-like: [![container holding gr...
I am starting be re-learn Chemistry after several years. The Book I am using has a test question to calculate the relative atomic mass of: $ (CH_3CO)_2O $ My take Carbon C, $ A_r = 56 $ <br> Hydrogen H, $ A_r = 1 $ <br> Oxygen O, $ A_r = 16 $ $ M_r = ( 56 + 1 \times 3 + 56 + 16 ) \times 2 + 16 = 131 \t...
I am starting be re-learn Chemistry after several years. The Book I am using has a test question to calculate the relative atomic mass of: $ (CH_3CO)_2O $ My take Carbon C, $ A_r = 56 $ <br> Hydrogen H, $ A_r = 1 $ <br> Oxygen O, $ A_r = 16 $ $ M_r = ( 56 + 1 \times 3 + 56 + 16 ) \times 2 + 16 = 131 \t...
In P/V graphs of Irreversible processes only initial and final state is defined due to sudden compression or rarefaction then how is Work done a path function in Irreversible processes. [![Irreversible process][2]][2] [![Isothermal irreversible expansion PV graph][1]][1] Why won't work done by the process here ...
**Water loses kinetic energy when it detaches from the surface of the ice** Water molecule in the solid phase have more hydrogen bonds than in the liquid phase. It takes energy to break these bonds, so only molecules with sufficient kinetic energy will detach (maybe because they just collided with a water molecule t...
Once a part of a peptide an amino acid is no longer an amino acid, so how do we refer to the part of the peptide that was once amino acid x?
How does one refer to the amino acids in a peptide?
In $P/V$ plots of irreversible processes only initial and final state is defined due to sudden compression or rarefaction then how is work done a path function in irreversible processes. [![Irreversible process][2]][2] [![Isothermal irreversible expansion PV graph][1]][1] Why won't work done by the process here ...
Is irreversible work a path function?
This fact was given as an explanation as to why branched isomers of a compound has lower boiling points. How are branched isomers less polarisable and how does this relate to London dispersion forces?
Why are branched isomers less polarisable?
This fact was given as an explanation as to why branched isomers of a compound have lower boiling points. How are branched isomers less polarisable and how does this relate to London dispersion forces?
I am doing an experiment that aims to determine if the rate of electroplating changes with the temperature. I am using a copper rod, a solution of copper(II) ions and a neutral rod to be coated. I also want to keep every other variable the same, which means the voltage across the rods, the concentration of the solution...
I've encountered in chemistry quite a lot of reducing agents. However one question strikes me quite often and any research done on the same hasn't been fruitful. This is in context to organic chemistry. Now for example, in reductive ozonolysis, we often use ozone in combination with Zinc and water. Zinc's presence ens...
For my chemistry investigation, I used Stamm's potassium permanganate method to investigate tea tannins with potassium permanganate to find the tannin content of teas. The method assumes complete oxidation of tea polyphenols to carbon dioxide. Assuming that the tea polyphenols consist of only theaflavins, $\ce{C29H...
I have a question about the toxicity of the pigments Cadmium Selenide (Cadmium Red), Cadmium Sulfide (Cadmium Yellow), Mercury Sulfide (Cinnabar or Vermillion) and Lead Oxide (Lead White). Not long ago the EU banned lead-white pigments from use, even for art. It is now generally impossible to get hold of lead-white ...
How to use Google’s Alpha-fold to predict the binding of two proteins?
An **exothermic reaction** occurs when the temperature of a system increases due to the evolution of heat. This heat is released into the surroundings, resulting in an overall *negative* quantity for the heat of reaction (-ΔE ). An **endothermic reaction** occurs when the temperature of an isolated system decreases...
How to use Google’s Alpha-fold to predict the complex crarted by two proteins?
How to use Google’s Alpha-fold to predict the complex formed from two proteins?
Are you asking how to use code developed to find the MFE (minimum free energy) structure of a single protein to determine the sturcture of a two-protein complex? Or are you asking if you can use the folding of a concatenated protein as a surrogate to determine the structure of the two-protein complex? If you're a...
An **exothermic reaction** occurs when the temperature of a system increases due to the evolution of heat. This heat is released into the surroundings, resulting in an overall *negative* quantity for the heat of reaction (-ΔE ). An **endothermic reaction** occurs when the temperature of an isolated system decreases...
Are you asking how to take code developed to find the MFE (minimum free energy) structure of a single protein, and modify it to instead determine the structure of a two-protein complex? Or are you asking if you can use this code, as is, to fold a concatenated combination of the two proteins, and in turn use this r...
How to use Google’s Alpha-fold to predict the complex formed from two proteins?
Are you asking how to take code developed to find the MFE (minimum free energy) structure of a single protein, and modify it to instead determine the structure of a two-protein complex? Or are you asking if you can use this code, as is, to fold a concatenated combination of the two proteins, and in turn use this r...
We installed 20 2" drop in anchors to anchor several signs in place near the entrance of our pool. We have to remove the signs about twice a year and after the end of the past season, I noticed there is a small amount of rust forming. I purchased the 304 because it was not going to be in direct contact with the water a...
I am studying haemoglobin absorption spectra in its oxygenated and deoxygenated state and I compiled values from different sources including: - A PhD thesis by van Assendelft \[1\], using extinction coefficients in (mmol/L)-1/cm - A book compiling almost one century of research on the topic by the same laboratory...
How to use Google’s Alpha-fold to predict the structure of a two-protein complex?
> Given the structure below, sketch the $^{13}$C - spectrum in a $^{13}$C marked sample > The data given is the chemical shifts (left) and the coupling constants (right) > [![enter image description here][1]][1] > [![enter image description here][2]][2] **The correct spectrum is given at the end of this qu...
Are you asking how to take code developed to find the MFE (minimum free energy) structure of a single protein, and modify it to instead determine the structure of a two-protein complex? Or are you asking if you can use this code, as is, to fold a concatenated combination of the two proteins, and in turn use this r...
How to use Google’s Alpha-fold to predict the structure of a two-protein complex?
How to use Google’s Alpha-fold to predict a two-protein complex?
Which would produce the largest change in the H2O level when added to water in a 25 mL graduated cylinder? (A) 10.0 g of Hg (d=13.6g/mL) (B) 7.42 g of Al (d=2.70g/mL) (C) 5.09 g of iron pyrite (d=4.9g/mL) (D) 2.68 g of oak (d=0.72g/mL) <br /> I approached this question by dividing the mass by density t...
Because oak has a density less than water (1g/mL), it won't be fully submerged. For substances more dense than water, they will be fully submerged so you don't have to worry about it. See [this video][1] to calculate how much of the oak will be submerged. [1]: https://www.youtube.com/watch?time_continue=151&v=sM...
> Which would produce the largest change in the $\ce{H2O}$ level when added to water in a $\pu{25 mL}$ graduated cylinder? > (**A**) $\pu{10.0 g}$ of $\ce{Hg}$ $(d = \pu{13.6 g/mL})$ > (**B**) $\pu{7.42 g}$ of $\ce{Al}$ $(d = \pu{2.70 g/mL})$ > (**C**) $\pu{5.09 g}$ of iron pyrite $(d = \pu{4.9 g/mL})$ > ...
## Below a more general approach. Suppose that we have two weak acids $\ce{HA}$ and $\ce{HB}$. The initial concentrations are $C^0_\ce{HA}$ and $C^0_\ce{HB}$, and their constants are $K_{\mathrm{a},\ce{(HA)}}$ and $K_{\mathrm{a},\ce{(HB)}}$. Suppose yet that volumes, $V_\ce{HA}$ and $V_\ce{HB}$, are additives. So...
Cheap and effective path [to attack iron is employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6AEwEXoECAoQAQ#v=onepage&...
Cheap and effective path [to attack iron is employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6AEwEXoECAoQAQ#v=onepage&...
Cheap and effective path [to attack iron is employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6AEwEXoECAoQAQ#v=onepage&...
Cheap and effective path [to attack iron is employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6AEwEXoECAoQAQ#v=onepage&...
Cheap and effective path [to attack iron is employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6AEwEXoECAoQAQ#v=onepage&...
Cheap and effective path [to attack iron is employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6AEwEXoECAoQAQ#v=onepage&...
I don't know if I am overcomplicating things but I am having trouble understanding the difference between H-NMR with C$^{13}$ sample and C$^{13}$-NMR. For example, if I have the molecule below and I am asked to sketch the H-NMR spectrum knowing that the carbons are C$^{13}$ and a C$^{13}$-NMR spectrum, what is t...
Simple, 'dumb' question.... Is the kJ/mol number given in tables of bond strengths or bond dissociation energies , when it comes to double and triple bonds, just for the 'last' bond or for both (or all three) together?
For BDEs of double and triple bonds, is number shown in tables for that second or third bond? Or all of them?
Try this, apply a cheap and effective spray onto the [iron surface employing hypochlorous acid](https://books.google.com/books?id=aZQ3AAAAMAAJ&pg=PA379&lpg=PA379&dq=hypochlorous+acid+attacking+iron&source=bl&ots=sCyzpeACQ5&sig=ACfU3U1cLGmDv8kV2L9CB1LMLAn0y7RBjg&hl=en&ppis=_c&sa=X&ved=2ahUKEwiqkKC9_Y_oAhVHTt8KHTWTAYwQ6A...
For bond dissociation energies (BDEs) of double and triple bonds, is number shown in tables for that second or third bond? Or all of them?
## Below a more general approach. Suppose that we have two weak acids $\ce{HA}$ and $\ce{HB}$. The initial concentrations are $C^0_\ce{HA}$ and $C^0_\ce{HB}$, and their constants are $K_{\mathrm{a},\ce{(HA)}}$ and $K_{\mathrm{a},\ce{(HB)}}$. Suppose yet that volumes, $V_\ce{HA}$ and $V_\ce{HB}$, are additives. So...
## Below a more general approach. Suppose that we have two weak acids $\ce{HA}$ and $\ce{HB}$. The initial concentrations are $C^0_\ce{HA}$ and $C^0_\ce{HB}$, and their constants are $K_{\mathrm{a},\ce{(HA)}}$ and $K_{\mathrm{a},\ce{(HB)}}$. Suppose yet that volumes, $V_\ce{HA}$ and $V_\ce{HB}$, are additives. So...
At school(high school), to calculate the voltage needed for electrolysis, we calculate the voltage produce if the elements were in a galvanic cell, preceded by a minus. So if a galvanic cell with Cu and Cr would produce 1,14V, we would say that an electrolysis with Cu and Cr will need -1.14V. But why do we do this...
CO2 kills humans. Does it also kill organisms? Does it also kill viruses?
CO2 kills humans. Does it also kill organisms?
Covalent bond is a strong bond compared to Ionic Bonds but Ionic Compounds have higher melting and boiling points then covalent compounds. **Why?**
The material I've synthesised is made up of two primary parts at a 1:1 ratio. It's one part; Agar, glycerol, water. Second part; Polyurethane resin. The agar mixture on its own was too soft, so I added the resin to harden the material. Would this material be classified as a hybrid composite? If not, why?
Is it appropriate to call this material a hybrid composite?
I buy and drink Nescafe Gold all the time. I also buy the smaller "caffeine-free" version of the same product. It tastes very differently, which makes me assume that the caffeine does have a lot of taste. However, maybe it's not simply due to the lack of caffeine? Maybe the process with which they "de-caf" the origi...
I have a little bit of problem trying to figure out the mechanism for the synthesis of Meldrum Acid. Meldrum acid is synthesis by a condensation reaction of acetone with malonic acid in acetic anhydride. [![enter image description here][1]][1] First, the carboxyl OH will be acetylated by acetic anhydride. But I c...
There's a "pair-fitting" function in pymol that will align molecules given some user-defined reference atoms, and output an RMSD across those points of comparison. You can get pymol educational [version for free][1], so students would be able to install it themselves. [1]: https://pymol.org/edu/?q=educational/
The material I've synthesised is made up of two primary parts at a 1:1 ratio: - Part 1: agar, glycerol, water. - Part 2: polyurethane resin. The agar mixture on its own was too soft, so I added the resin to harden the material. Would this material be classified as a hybrid composite? If not, why?
I am quiet new to this field of chemistry. I work with GaussView and I created a surface plot for my molecule with the cube and surface generator. This works very well. Now I like to save and copy this image of my molecule with its surface. My favorite file type whould be a vector graphic type (eps or svg). I don not ...
How to extract a image (vector graphic) from a surface EPS plot with GaussView?
So I've been trying to understand what exactly aromaticity means, and I've come to know that compounds possessing benzene rings are aromatic, like toluene and phenol. It thus made sense to me that the benzylic carbocation should be aromatic, as it fulfills all conditions of Huckel's rule. However, I found no mention of...
Is the benzylic carbocation aromatic?
Certain objects such as metals, glass, plastic, sugar etc. melt when heated to a certain temperature but other materials such as a piece of wood, paper, a piece of rock etc. do not. Why is that?
Why don’t all objects melt and liquefy when heated sufficiently?
I am working with lithium ion batteries having the cathode material as NMC i.e. LiNixMnyCozO2, wherein x + y + z = 1. The proportion of Nickel, Manganese and Cobalt in the cathode varies, but mostly Nickel is either equal to or greater than the amount of Manganese and Cobalt in the cathode (for example NMC-111, NMC-532...
>Di-hydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction: >$CH_4{_{(g)}}+H_2O_{(g)} \ce{<=>} CO_{(g)}+3H_2{_{(g)}}$ >How will the values of $K_p$, $K_c$ and composition of equilibrium mixture be affected by increasing the pressure ? Now, 1) Accordi...
In terms of energy per gram of reactants, the evaporation of water at -2.2 kJ/g, is much higher than any chemical endothermic reaction that I have seen demonstrated. At [extreme temperatures][1] there is no real limit, but for reactions that occur at a reasonable rate at room-temperature it seems water is hard to beat....
I just thought that the reaction should follow SN2 mechanism this is because the alkyl halide is primary but the book says that the reaction will follow SN1 mechanism resulting in the formation of tertiary carbonation and a ring expansion product. Can anyone please explain the reason behind this ?
Which mechanism should a reaction between the cyclopentylmethanol and the HBr should follow?
$K_p$ will *not* change with pressure, only with temperature. $Q_p$ will instantaneously increase upon applying the pressure for this reaction (why? see below), and will drive the reaction to reactants to re-achieve equilibrium (decreasing $Q_p$) until $Q_p$ = $K_p$ once again. From a LeChatelier approach, you have mo...
$K_p$ will *not* change with pressure, only with temperature. $Q_p$ will instantaneously increase upon applying the pressure for this reaction (why? see below), and will drive the reaction to reactants to re-achieve equilibrium (decreasing $Q_p$) until $Q_p$ = $K_p$ once again. From a LeChatelier approach, you have mo...
Wood can melt, in a limited way, under certain circumstances, such as friction welding. For a dramatic video, see: https://www.facebook.com/interestingengineering/videos/1891004754302553/ See also: http://web.utk.edu/~mtaylo29/pages/Wood%20welding.htm?fbclid=IwAR1MLgBtkfESlYiaP0iEaXbv36AtLy8yXEj0iCqFaaVYBcDRitx...
The lignin, and some of the hemicelluloses, in wood can melt under certain circumstances, such as friction welding. For a dramatic video, see: https://www.facebook.com/interestingengineering/videos/1891004754302553/ See also: http://web.utk.edu/~mtaylo29/pages/Wood%20welding.htm?fbclid=IwAR1MLgBtkfESlYiaP0iEaXb...
I came across the compound 3-methylpentan-2-ol. Looking at its proton NMR spectra, it seems there is a lot of splitting for the signal at 4ppm. [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/vAMRu.gif I'm assuming that the 4ppm represents the proton in the hydroxyl group (since it ...
Why do certain signals in proton NMR experience extensive splitting despite only having 1 neighbour?
To an evacuated vessel with movable piston under external pressure of 1 atm, 0.1 mol of He and 1 mol of unkown compound(vapour pressure 0.68 atm at 273K) are introduced. Considering ideal gas behaviour, calculate the total volume of 2 gases at 273K. My doubt is that why cant I add the moles of He and the unkown compou...
I came across the compound 3-methylpentan-2-ol. Looking at its proton NMR spectra, it seems there is a lot of splitting for the signal at 4 ppm. [![3-methylpentan-2-ol NMR spectra][1]][1] [1]: https://i.stack.imgur.com/vAMRu.gif I'm assuming that the 4 ppm represents the proton in the hydroxyl group (sinc...
> To an evacuated vessel with movable piston under external pressure of $\pu{1 atm},$ $\ce{0.1 mol}$ of $\ce{He}$ and $\pu{1 mol}$ of unknown compound (vapour pressure $\pu{0.68 atm}$ at $\pu{273 K})$ are introduced. Considering ideal gas behavior, calculate the total volume of 2 gases at $\pu{273 K}.$ Why can't I a...
Would alkyl bromide/alkyl chloride form when an alcohol reacts with thionyl bromide/thionyl chloride?