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Ammonia as a cleaning agent.
Ammonia is a historically notable cleaning agent. It was readily available, prior to the advent of the industrial era, as it is a natural by-product of the breakdown of animal (and human) waste <sup>(1)</sup>. Aging urine produces a liquid with a high ammonia content. Ammonia has signif... |
Given an alcohol-water solution (Liquor products) that may have additives and/or may have been aged in wood, I'd like to boil off the alcohol and the water to leave behind the various additives in a highly repeatable fashion.
I.e. a pan on the stove works OK, but I'd potentially like to throw together something a bi... |
Ammonia is a historically notable cleaning agent. It was readily available, prior to the advent of the industrial era, as it is a natural by-product of the breakdown of animal (and human) waste <sup>(1)</sup>. Aging urine produces a liquid with a high ammonia content. Ammonia has significant antimicrobial properties <s... |
I saw rubber-like silicones. Are there types of silicone that can be used in injection molding and once the process is finished - become as hard as regular plastic? At the same time they should have all(/majority) of silicone's properties (citing Wikipedia):
- Low thermal conductivity
- Low chemical reactivity
- L... |
i was asked to synthesis this compound from this amino acid, i first alkylated the alpha carbon using enolate alkylating method then i esterficated the amino acid but i'm doubtful that my steps are right, do i need to protect the amino group in the esterification step? or even before ?
[![enter image description here]... |
The US published application US20110190402 titled “Synthetic wood composite” appears to be very close to answering your question: “Is there research into making wood from its constituents.” The full text can be found here: https://patentscope.wipo.int/search/en/detail.jsf?docId=US73316434&tab=PCTDESCRIPTION&_cid=P10-K... |
We know the basic Thermodynamic equations are:
$$ dU=-PdV+ TdS + \mu dN$$
$$ dH=dU+d(PV)= TdS+ \mu dN + VdP$$
we typically assume constant Pressure for a reaction carried out in air and neglect the dP term
$$dG=dH-d(TS)= \mu dN - SdT+ VdP$$
once again we neglect the dT and dP terms
but for heat of reaction we us... |
Based on this page in a “Blaze” book, my six year old asked “which would win?” between water and lava. On further investigation, we refined the question to: which would turn solid first in similar conditions, a liter of room temperature water or a liter of volcanic lava?
[![From “Nickelodeon Amazing Adventures”][1]][1... |
Placed in equivalent freezers, would a liter of water or a liter of lava turn from liquid to solid first? (question from a 6 year old) |
**Good question**
You need to specify the conditions a bit more completely:
* At 1 °C, the water would *never* freeze, while the molten lava might in an hour.
* At -50 °C, not uncommon near [Mt. Erebus][1], an uninformed guess on my part is that water would freeze first... depending:
* What is the shape of ... |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
> Placed in equivalent freezers, would a liter of water or a liter of lava turn from liquid to solid first? (question from a 6 year old)
Based on this page in a “Blaze” book, my six year old asked “which would win?” between water and lava. On further investigation, we refined the question to: which would turn so... |
I read that the chemicals potassium hydroxide and sodium hydroxide are extremely corrosive and will cause severe burns but I also see videos of people saying that if you get lye on you, then just wash it off and you’ll be fine. Is that actually ok. The fact that the stuff is sold in hardware stores makes it seem even l... |
Are burns from Lye or Potash that bad? |
## General Case
This question concerns the general problem of accurate volume measurement of a given object. Among other techniques, that of liquid displacement is sometimes used for this purpose.
- In case of a **solid material**, the latter may be immersed in liquid, and its volume calculated by measuring t... |
I saw rubber-like silicones. Are there types of silicone that can be used in injection molding and once the process is finished - become as rigid as, let's say PVC? At the same time they should have all(/majority) of silicone's properties (citing Wikipedia):
- Low thermal conductivity
- Low chemical reactivity
- L... |
What is the reaction of dissociation of lauryl glucoside? It's aqueous solution pH is much higher than 7, it's definately alkaline. Why is that? It's nonionic surfactant and as far as I know it only creates hydrogen bonds with water (the hydrophilic part of the molecule, oxygen atom). Lauryl glucoside is the combinatio... |
Why is aqueous solution of lauyl glucoside alkaline? |
So I have a home lab setup and recently found myself in need of some nitric acid. I could just buy some, but I thought it would be a useful exercise to make my own. I have plenty of nitrate salts around, as well as plenty of unused ~30% sulfuric acid (battery acid refills, fresh out of the box so there's no lead etc in... |
How concentrated does sulfuric acid need to be for nitric acid synthesis (H2SO4 + nitrate salt distillation)? |
So I have a home lab setup and recently found myself in need of some nitric acid. I could just buy some, but I thought it would be a useful exercise to make my own. I have plenty of nitrate salts around, as well as plenty of unused ~30% sulfuric acid (battery acid refills, fresh out of the box so there's no lead etc in... |
Why do we consider the normal and extreme limits for Ramachandran plots to be less than the Van Der Waal distances between two atoms?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/sUrEI.png |
Why would the following reaction not proceed through SN2 reaction? |
To calculate pH of a weak acid, we calculate the dissociation constant using $K_a$ expression. Every problem I've read on pH calculation of weak acids, didn't take $\ce{H+}$ of water into account. I speculated that maybe expression for $K_a$ already takes hydrogen ions from water into account. Is that true? Or is that ... |
Does $K_a$ take hydrogen ions from water into account? |
To calculate $\mathrm{pH}$ of a weak acid, we calculate the dissociation constant using an expression for $K_\mathrm{a}.$ Every problem I've read on $\mathrm{pH}$ calculation of weak acids doesn't take $\ce{H+}$ of water into account. I speculated that maybe expression for $K_\mathrm{a}$ already takes hydrogen ions fro... |
Does the acid dissociation constant takes hydrogen ions from water into account? |
I can't present you a movie of electron interactions, but maybe a fuzzy picture. Imagine a metal body (start with copper): the atoms are held in a solid structure - in a sea of electrons! Those loose electrons can be pushed around easily, so we can make wires out of copper and transmit electricity thru them. If you put... |
**Disclaimer: I am not a chemist by any means, and I only have knowledge limited to what I learned in my university's Chemistry III course. Basic understanding of everything up to valence electron orbitals.**
Why is there no set of rules to follow which can predict the product of chemical reactions? To me, it seems ... |
Why is chemistry unpredictable? |
Your question and your formulas are really asking about two different things.
**Let's look at your formulas first.**
$$\ce{H2O + HA <=> H3O+ + A-},\tag{R1}$$
$$\ce{HA <=> H+ + A-}?\tag{R2}$$
For R1 the equilibrium equation should be:
$$\mathrm{K_a} = \dfrac{\ce{[H3O+][A-]}}{\ce{[H2O][HA]}}\tag{Eq-1}$$
... |
Your question and your formulas are really asking about two different things.
**Let's look at your formulas first.**
$$\ce{H2O + HA <=> H3O+ + A-},\tag{R1}$$
$$\ce{HA <=> H+ + A-}?\tag{R2}$$
For R1 the equilibrium equation should be:
$$\mathrm{K_a} = \dfrac{\ce{[H3O+][A-]}}{\ce{[H2O][HA]}}\tag{Eq-1}$$
... |
First of all, I'd ask: what do you admit as "chemistry"? You mentioned thermodynamics as being a field where you have "models to predict results". But [thermodynamics is extremely important in chemistry](https://en.wikipedia.org/wiki/Chemical_thermodynamics); it's not right to classify it solely as being physics. There... |
What makes concentrated aqueous solutions of aluminium nitrate and aluminium chloride suitable to dissolve noble metals, specifically gold? |
**Parts of chemistry have predictability but the combinatorial complexity of what is possible leaves a large amount of space for things that don't follow the rules**
Some of the ways chemistry differ from physics in unpredictability are an illusion. Take gravity, for example. There is a strong rule–sometimes describ... |
"it seems that every other STEM field has models to predict results (physics, thermodynamics, fluid mechanics, probability, etc) but chemistry is the outlier"
This is only partially true, but there are areas of all of those fields where predictive power is difficult in practice due to the complexity of the system an... |
In some class II force fields, there are cross-terms that characterize bond-bond, bond-angle interactions and others. Example of equations below:
<a href="https://www.codecogs.com/eqnedit.php?latex=\sum_{bond-bond}^{}k_{bb}(b-b_{0})(b^{'}-b^{'}_{0})" target="_blank"><img src="https://latex.codecogs.com/gif.latex?\su... |
How are class II force field cross-terms derived? |
I know that in rational design sometimes the researcher might use Cl or F instead of a H-Bond donor/acceptor. **What kind of interaction does a halogen provide compared to the H-bond donor/acceptor? When might it be better to use one compared to another for best binding affinity?**
Below is a picture of a small mol... |
What interaction is occurring here? Which should I use? Why? |
Halogen vs H-Bond Donor/Acceptor: How do they differ? |
I know that in rational design sometimes the researcher might use Cl or F instead of a H-Bond donor/acceptor. **What kind of interaction does a halogen provide compared to the H-bond donor/acceptor? When might it be better to use one compared to another for best binding affinity?**
Below is a picture of a small mol... |
I know that in rational design sometimes the researcher might use Cl or F instead of a H-Bond donor/acceptor. **What kind of interaction does a halogen provide compared to the H-bond donor/acceptor? When might it be better to use one compared to another for best binding affinity?**
Below is a picture of a small mol... |
I have been using potassium hydrogen phthalate (KHP) for creating primary standards. I have looked into the Flinn catalog, and the disposal consideration is classified as "organic acids, must be neutralized prior to drain disposal." That seems easy enough, but with recent publications of health concerns of phthalate ex... |
Is it OK to dispose of potassium hydrogen phthalate into the sewer system? |
When making aerogel using supercritical fluids the liquid in the gel is replaced by a gas. Can this be achieved using n-Hexane as the supercritical fluid? What would the resulting gas be? Would it be safe to do or even possible?
|
Can you make n-Hexane a supercritical fluid? |
I was given a question where I had to write the orbital notation of Osmium (Os) and I got it wrong.
**The question:**
6s2 --> ↑↓ 4f --> ↑↓↑↓↑↓↑↓↑↓↑↓↑↓ 5d6 --> ↑↓↑↓↑↑
The arrows above are my answer. What did I do wrong? I think it might be my answer to 5d6 but I am not sure. How many unpaired electrons are i... |
What did I do wrong in my orbital notation for the Os (Osmium)? |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
In some class II force fields, there are cross-terms that characterize bond-bond, bond-angle interactions and others. Example of equations below:
$$\sum_{bond-bond}^{}k_{bb}(b-b_{0})(b^{'}-b^{'}_{0})$$
$$\sum_{bond-angle}^{}k_{ba}(b-b_{0})(\theta^{'}-\theta^{'}_{0})$$
My question is: how do I get the $k_{bb}$ an... |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
What did I do wrong in my orbital notation for this Os (Osmium) question? |
Let me contribute two more reasons which make Chemistry hard to analyse from a purely theoretical standpoint.
The first one is that, viewed **very** abstractly, Chemistry essentially relies on the study of geometry in very high-dimensional spaces, and even from a purely mathematical point this can be extremely diffi... |
The liquid crystal can be control using polarizes light which is means we can controlling the arrangement of the liquid crystal molecules then the light pass through it can be manipulated. what is expmle for this? what is the relashionship
between liquid crystal and light pass through it? |
The liquid crystal can be control using polarizes light. This means we can control the arrangement of the liquid crystal molecules, then when the light passes through it can be manipulated.
But why exactly is this possible? What is the relationship between liquid crystal material and light pass through it? How do t... |
First of all, I'd ask: what do you admit as "chemistry"? You mentioned thermodynamics as being a field where you have "models to predict results". But [thermodynamics is extremely important in chemistry](https://en.wikipedia.org/wiki/Chemical_thermodynamics); it's not right to classify it solely as being physics. There... |
What exactly is the mechanism by which Benedict’s test works for reducing sugars? As I understand it the free hemiacetal groups on reducing sugars opens up and an aldehyde is formed, this is then oxidised by Cu<sup>2+</sup> which then results in a red copper(I) oxide.
RCHO + 2 Cu<sup>2+</sup>+ 5 OH<sup>-</sup> → RCO... |
How does the Benedicts Test work? |
Can H+ ion exist independently since it does need to form any bonds.Why do we say that it needs to be in H30+ ion form?
|
Can H+ ion exist independently? |
How Is This Acid Base Map Established? |
I am an electrician apprentice in charge of a large number of pH-sensors/transmitters at a power plant and chemical plant.
I do all the pH-instrumentation related maintenance, calibration, adjustments etc.
By studying pH measurements I have learned about the Nernst equation. The transmitter is able to (via an inb... |
I bought 100g of SiO₂ hydrophobic of 20 nanometers. I'm trying to make my own "car body wax". This "wax" that you can buy on the internet allows to make water repellent on car bodies : https://www.youtube.com/watch?v=JRtNpGQM53E
I did a quick test by mixing a few grams of SiO₂ with water and then put on my car body.... |
The claims in the video are surely exaggerated: protection for 6 months? In a garage, perhaps.
The video claims that the hydrophobic silica - $SiO_2$ - is activated by water. The final product is applied to a wet car body with water droplets severely beaded up - i.e., already hydrophobic from the pretreatment washin... |
You could use a permanent gas analyzer that has an FID channel for hydrocarbons and CO2, with a TCD detector for H2 and HF and a third MS channel if needed. Basically, this would mean you split your sample into three different columns in the oven to analyze them for different things. I agree with Karl and don't reinven... |
I was reading salt hydrolysis of a salt made from strong acid and weak base. I came across the hydrolysis of $\ce{NH_4Cl}$. These reactions were mentioned
>$$\ce{NH_4Cl + H_2O<=>NH_4OH + HCl \tag{R1}}$$
$$\ce{NH_4+ + Cl- + H_2O<=>NH_4OH + H+ + Cl-}\tag{R2}$$
$$\ce{NH_4+ + H_2O<=>NH_4OH + H+\tag{R3}}$$
In the se... |
Will a salt dissociate completely in water to give free ions? |
I was reading salt hydrolysis of a salt made from strong acid and weak base. I came across the hydrolysis of $\ce{NH_4Cl}$. These reactions were mentioned
>$$\ce{NH_4Cl + H_2O<=>NH_4OH + HCl \tag{R1}}$$
$$\ce{NH_4+ + Cl- + H_2O<=>NH_4OH + H+ + Cl-}\tag{R2}$$
$$\ce{NH_4+ + H_2O<=>NH_4OH + H+\tag{R3}}$$
In the ... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It is a golden opportunity to explain "heat" and state-change in general terms, rather than needing a hard answer.
Disclaimer: I am an armchair scientist/engineer, but I love this stuff (until the greek symbols show up).
The r... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It is a golden opportunity to explain "heat" and state-change in general terms, rather than needing a hard answer.
Disclaimer: I am an armchair scientist/engineer, but I love this stuff (until the greek symbols show up).
The r... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It is a golden opportunity to explain "heat" and state-change in general terms, rather than needing a hard answer.
Disclaimer: I am an armchair scientist/engineer, but I love this stuff (until the greek symbols show up).
The r... |
First of all, I'd ask: what do you admit as "chemistry"? You mentioned thermodynamics as being a field where you have "models to predict results". But [thermodynamics is extremely important in chemistry](https://en.wikipedia.org/wiki/Chemical_thermodynamics); it wouldn't be right if we classified it as being solely phy... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It is a golden opportunity to explain "heat" and state-change in general terms, rather than needing a hard answer.
Disclaimer: I am an armchair scientist/engineer, but I love this stuff (until the greek symbols show up).
The r... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It shows the child has taken the information in the book and re-applied it to a new problem (the stated question was about freezing and has nothing to do with steam, contrary to a previous answer). He seemingly already understands ... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It shows the child has taken the information in the book and re-applied it to a new problem (the stated question was about freezing and has nothing to do with steam, contrary to a previous answer). He seemingly already understands ... |
The thermodynamics involved might overwhelm the child, but the question is a good one. It shows the child has taken the information in the book and re-applied it to a new problem (the stated question was about freezing and has nothing to do with steam, contrary to a previous answer). He seemingly already understands ... |
Below is a picture of the radial component of the wave function distribution for the 1 through 3s orbitals. It makes sense to me that there are points where the wave function is 0, since by definition, a radial node is where the wave function = 0.
[![][1]][1]
What confuses me is the following graph of the 2p or... |
How is it possible to draw a radial wave function for the 2p orbital? |
Can anyone tell me the exact ABS material (brand and number) used for Lego?
Is it food grade material?
Kind regards |
What is the exact material brand and model number of Lego (ABS)? |
**Disclaimer: I am not a chemist by any means, and I only have knowledge limited to what I learned in my university's Chemistry III course. Basic understanding of everything up to valence electron orbitals.**
Why is there no set of rules to follow which can predict the product of chemical reactions? To me, it seems ... |
Something that confuses me slightly is the trends in density when comparing periods 4, 5, and 6 in the d-block. Looking at periods 5 and 6, the density peaks at group 8, with ruthenium and osmium, respectively. The density slightly drops at group 9 and falls further through group 10-12 and the p-block.
But in period... |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
... |
Let me contribute two more reasons which make chemistry hard to analyse from a purely theoretical standpoint.
The first one is that, viewed **very** abstractly, chemistry essentially relies on the study of geometry in very high-dimensional spaces, and even from a purely mathematical point this can be extremely diffi... |
I'm new to posting on stack exchange, although I've read a lot of it before. This question seems like it might end up being marked as a duplicate, but I've looked through a lot of the similar questions and I feel like I'm still not getting it (most answers end up just explaining that the octet rule is wrong).
I'm cu... |
Why does the Most Stable State of an Atom Tend to be One with Full s and p Subshells? |
Light travels length $l$ through a medium with $n$ independently absorbing species with extinction coefficients $\alpha_1,\dots,\alpha_n$. According to Beer-Lambert law, the amount of light absorbed is
$$1-T=1-\exp\left(-l\sum_i \alpha_i\right)=1-\prod_i\exp(-\alpha_i l)$$
How do I find the amount of light absorb... |
Light travels length $l$ through a medium with $n$ independently absorbing species with extinction coefficients $\alpha_1,\dots,\alpha_n$. According to Beer-Lambert law, the amount of light absorbed is
$$1-T=1-\exp\left(-l\sum_i \alpha_i\right)=1-\prod_i\exp(-\alpha_i l)$$
How do I find the amount of light absorb... |
How can I determine the size? Are there some software available? The image is available below.
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/R8kHa.png |
I need to detemine the size of a Tropolone molcule? It's a 7 ring aromatic with O on the 1st C and OH on the 2nd C |
Since the overlap increases with directional properties of orbital,
$$\ce{p - p > s - s > s - p}$$
<img src="https://i.stack.imgur.com/3Jrak.png" title="CENTERED!">
However it is also observed that the bond strength of
$$\ce{H-F > H-H > F-F}$$
$$\ce{\{s - p > s - s > p - p\}}$$
Why does this happen?... |
I've seen the term 'by mass' being used in various sorts of contexts. Some, while explaining the law of definite proportions say, the 'same proportions by mass', some say 'constant chemical composition by mass'.
What does the term 'by mass' mean? Does it mean in a proportion/ratio, we have mass as both, the denomin... |
What does the term 'by mass' mean with respect to different contexts? |
Since the overlap increases with directional properties of orbital,
$$\ce{p - p > s - s > s - p}$$
<pre>
<img src="https://i.stack.imgur.com/3Jrak.png" title="CENTERED!">
</pre>
However it is also observed that the bond strength of
$$\ce{H-F > H-H > F-F}$$
$$\ce{\{s - p > s - s... |
It is not just a stain that could be cleaned off by dissolving or fine brushing by a wipe. The plastic is already damaged.
I see only few ways, none really good :
- Colour the spots by some colour ( markers ? ) to be as least disturbing as possible.
- Peel off the damaged spots to the undamaged layers, but t... |
Since the overlap increases with directional properties of orbital,
$$\ce{p - p > s - s > s - p}$$
<img src="https://i.stack.imgur.com/3Jrak.png" title="CENTERED!">
However it is also observed that the bond strength of
$$\ce{H-F > H-H > F-F}$$
$$\ce{\{s - p > s - s > p - p\}}$$
Why does this happen?... |
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