Questions tagged [decomposition]
For questions about the decomposition of any chemical species, under any certain conditions.
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Anhydrous Chromium Alum production
I recently started a small project of making home-made chromium alum crystals, as can be found on many sites, videos and recipes all around the internet.
I tried calculating the amount of salt I ...
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42 views
Thermal decomposition of steam to hydrogen and oxygen; at what temperature is half decomposed and how to calculate?
In comments below this answer in Space Exploration SE I've said:
(Wikipedia) says that dissociating water costs about 4.4 eV per bond. If 𝑘𝐵𝑇= 4.4 eV and $k_B$ is 8.617E-05 eV/K then that ...
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1answer
42 views
What does ethylene glycol decompose to when exposed to air for an extended period of time?
I came across this article on wikipedia on ethylene glycol stating that it decomposes fairly quickly. I was under the impression that ethylene glycol was dangerous to let leach into soil, but I think ...
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1answer
55 views
Decomposition of Metal Nitrates
An entrance JEE Main & Advanced AIEEE 2003 exam question:
Which one of the following nitrates will leave behind a metal on strong heating?
A. Copper nitrate
B. Manganese nitrate
C. ...
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1answer
249 views
Thermal decomposition of K2CO3
K2CO3 doesn't boil - it thermally decomposes at 1200c. However, I find conflicting information online about this. Roughly what I have found say three inconsistent things.
(1) It doesn't decompose (...
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310 views
How to predict the decomposition products of for example barium carbonate?
I am a high school student studying basic chemistry and I am confused about the process of writing decomposition reactions.
The question I have encountered asks me to decompose $\ce{BaCO3}$.
Online, ...
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1answer
82 views
Could Calcium Oxide be made from CaCO3 in a bonfire?
I have some chalk and I need to turn it into CaO. Would a big bonfire be hot enough to make it? If anyone has personal experience with this reaction please share, whether succesful or not
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$K_c$ vs $K$ in equilibrium reactions
I don’t understand why the following question
The decomposition of nitrosyl bromide $(\ce{NOBr})$ proceeds by the following reaction:
$$\ce{2 NOBr(g) <=> 2 NO(g) + Br2(g)} \qquad K = 0....
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2answers
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What is the most convenient way to prepare ferrous oxide (FeO) in the laboratory?
The Wikipedia page for ferrous oxide states that $\ce{FeO}$ can be prepared by the thermal decomposition of iron(II) oxalate, with the following reaction:
$$\ce{FeC2O4 → FeO + CO2 + CO}$$
And that ...
0
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1answer
66 views
Why does Comfrey Break Down Easily? [closed]
comfrey (Symphytum officinale) is a well known plant to organic growers. One of its features is that the leaves break down very quickly, either in water or in a container closed from UV light. There ...
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1answer
80 views
Iron(III) nitrate and hydrogen peroxide reaction
When iron(III) nitrate is added to hydrogen peroxide as a catalyst, the temperature initially decreases and begins to increase after 30 seconds. Why is this the case? (is there any intermediate ...
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Methods and observations that help you achieve complete decomposition of a compound in decomposition analysis [closed]
Different chemicals decompose in different ways to give different observations, but they usually involve heating the compound to high temperatures.
My question is that what are your lab techniques ...
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1answer
164 views
Does ethanol “decompose” or “remove” phosgene from chloroform?
A question I was asked was: "Why is ethanol added to chloroform bottles?". I know that chloroform can be slowly converted to poisonous phosgene gas, and that ethanol is added to prevent phosgene ...
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2answers
471 views
Why and how does hydrogen peroxide decompose in the presence of light?
When exposed to UV light, hydrogen peroxide decomposes into $\ce{H2O}$ and $\ce{O}$. Why does this happen and more importantly how? Is the energy from light absorbed by the bonds which are specific to ...
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116 views
Is there a quantitative test/analysis technique that can determine if some chloroform has degraded into phosgene?
Before I go to use any chemical that I've had in storage for a while, I try to check if it's degraded into something else (e.g.: checking the $\ce{H2O}$ content of $\ce{H2O2}$, checking for $\ce{H2O2}$...
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Is it possible to arrest the post-actinic effects of photodegradation in ABS polymers?
Polymers like acrylonitrile butadiene styrene (ABS) are adversely effected by UV exposure, both visually (by yellowing) and with regard to other material properties [1]. What's worse is that the ...
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109 views
What is the chemical equation for the digestion/decomposition of cellulose?
I'm trying to find the chemical equation/pathway from cellulose $\ce{(C6H10O5)_n}$ to methane $\ce{CH4}$. What are the other reactants or products in the reaction?
$$\ce{C6H10O5 + ? -> CH4 + ?}$$
...
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1answer
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What (simple) household chemicals react with oxygen?
I'm interested in making a small "preservation chamber" that I can basically use to store objects without the presence of oxygen. I have a resealable stainless steel canister and the plan is pretty ...
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1answer
264 views
Thermal decomposition of ester [closed]
I have a clear liquid with a faint sweet smell. I know this compound contains an aromatic group and an ester. However, something strange happens when I try to distill it - it forms a white solid. I ...
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0answers
53 views
Decomposition of Sugar Temperature
I am perplexed by information on the internet about the sugar raffinose.
The melting point of raffinose is 244.4°F
The boiling point of raffinose is 1,623°F
I can't find the temperature at which it ...
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1answer
132 views
Determining the formula of tin(II) chloride hydrate [closed]
$\pu{1.20 g}$ of hydrated tin chloride decompose to form $\pu{1.01 g}$ of anhydrous tin chloride on heating. Calculate the value of $x$ given
$$\ce{SnCl2.xH2O -> SnCl2 + x H2O}$$
I done it ...
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2answers
630 views
The thermal decomposition of NH4Cl [closed]
When you heat $\ce{NH4Cl}$ it decomposes into $\ce{NH3 + HCl}$ gases. My question is why does it decompose into ammonia and hydrogen chloride gases on the molecular level. Is it because in the $\ce{N-(...
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Mechanism for removal of pesticides from fruit by sodium bicarbonate
When Googling around for methods to remove pesticides from fruits and vegetables, a study commonly referred to from some news sites (e.g. here and here ) is one where soaking apples in a sodium ...
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1answer
250 views
Hydrate decomposition equation steps
When a hydrate decomposes it loses water molecules in steps.
Does each step have a chemical equation?
If so is the following equations for decomposition of cupric sulfate hydrate correct?
$$
\begin{...
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2answers
210 views
Can we combine two reactions and then calculate the equilibrium concentrations?
At a certain temperature, $\ce{N2O5}$ dissociates as:
\begin{align}
\ce{N2O5 (g) &<=> N2O3 (g) + O2 (g)} & K_1 &= 4.5
\end{align}
At the same time, $\ce{N2O3}$ also dissociates ...
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1answer
133 views
What is chemical decomposition in the context of a crystal or amorphous solid?
The IUPAC Gold Book definition of chemical decomposition is:
The breakdown of a single entity (normal molecule, reaction intermediate, etc.) into two or more fragments.
That is a very general ...
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1answer
227 views
Decomposition vs Combustion reaction
I'm balancing chemical equations, and I came across the following:
$$\ce{O2 + C4H9NH2 -> CO2 + H2O + N2}\tag{unbalanced}$$
My initial reaction was that it is a combustion reaction. According to ...
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1answer
93 views
Will gamma radiation cause “thermal” decomposition of sodium bicarbonate?
I am conducting research for a new drug that contains powdered sodium bicarbonate, and the drug will need to be sterilized after placement into it's container/closure system. Typically, this is ...
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1answer
522 views
How long does it take for nitric oxide to turn into dinitrogen and dioxygen?
I'm new to chemistry and am studying nitric oxide as a combustion accelerant. Nitric oxide is said to be a free radical.
People say that nitric oxide, by itself, is pretty stable. But I saw that $$\...
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Why does lithium aluminium hydride appear grey?
Commercial lithium aluminium hydride is a grey compound, which loses a lot of reactivity the darker it is. Luckily you can clean it up to get the reactive white compound and the separated grey ...
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1answer
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How do you stop a Pharoah's Serpent reaction?
I am a novelist and working on a book. I have been searching google for an answer to the above question. How does one stop a Pharoah's Serpent reaction? Thanks!
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2answers
53 views
Why is it so hard to turn plastics into something useful or decompose it? [closed]
Even after so many years, why haven't we yet come up with a solution to the plastic problem ?
Why are plastics so hard to decompose via chemical or physical processes into something harmless or ...
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1answer
84 views
Dissociation energy of benzene dimer
It is known that the benzene dimer has two stable structures, T-shaped ($\ce{C_{2v}}$) or parallel-displaced ($\ce{C_{2h}}$) structure.
Now the question is: does the dissociation energy ($\ce{D_0}$) $...
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2answers
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What are the crystals that have formed around the top of a conc. nitric acid bottle?
I was looking through my chemicals cupboard and found that this decades-old bottle of conc nitric acid had grown a beard. I can't think of any reaction between (presumably) $\ce{NO2}$ and any airborne ...
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1answer
216 views
Why is ordinary soap and water adequate to decontaminate possible nerve agents?
In the news it was announced that anyone who might have been exposed in the recent Salisbury nerve agent incident should wash any potentially contaminated clothing as normal using regular detergent ...
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1answer
2k views
What is the order of the catalytic decomposition of hydrogen peroxide?
I recently did an experiment to determine the activation energy of the decomposition of hydrogen peroxide using iron (III) chloride as a catalyst. I repeated this experiment at different temperatures. ...
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Are there any compounds with these properties? [closed]
I'm looking for a chemical compound that satisfies the following criteria:
Solid at room temperature
Decomposes into gases, primarily oxygen when supplied with an electrical current, preferrably ...
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0answers
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How long can solid DPPH powder last for in terms of shelf-life before its free-radical status is quenched by the atmosphere?
I am writing in my research on the free-radical scavenging activity of various flavylium compounds. I may need to have DPPH shipped as a result of a lack of supply; I am just wondering what sort of ...
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2answers
3k views
How to make ammonia from urea?
The chemical formula of urea is $\ce{CO(NH2)2}$ or is sometimes written as $\ce{CH4N2O}$. How would I decompose or precipitate the $\ce{CO}$ from urea to get ammonia? I know that in the olden days ...
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terminology for breakdown of liquid dielectric under the application of high voltage
I saw a diagram a while ago of increasing voltage (x-axis) and what seemed to be the chemical decompositions of ethylene glycol as it occurred at various applied voltages. (I am not a chemist- sorry ...
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2answers
2k views
Decomposition of LiNO3
I have a doubt about decomposition of alkali metals.
Why does $\ce{LiNO3}$ decompose to give $\ce{Li2O}$ and $\ce{NO2}$ where as other alkali metals decompose to give corresponding nitrite and oxygen?
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0answers
277 views
Shelf life of 1,4-Butanediol, colloquially known as BD or BDO
1,4-Butanediol is a chemical cleaning solvent used for industrial purposes and a precursor of GHB. Companies now post the "official" shelf life as "2 years", but a 1997 publication by BASF said GBL ...
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0answers
220 views
Were gold(II) complexes synthesized for the first time in 2017?
Recently in the Google news feed, I discovered this news:
Gold stabilized in very rare oxidation state +II
Missing golden link found: Divalent gold complex isolated for the
first time in a ...
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1answer
3k views
Reactions in the presence of sunlight
Some reactions in my textbook specify the need for the presence of sunlight,
eg-photolytic decomposition of silver bromide and substitution reaction of methane with chlorine.
What is going on in ...
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1answer
568 views
Dissociation constant of solid ammonium chloride [closed]
When solid ammonium chloride dissociates at a certain temperature in a $\pu{0.500 dm3}$ container, ammonia and hydrogen chloride are formed.
$$\ce{NH4Cl <=> NH3 + HCl}$$
The initial ...
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3answers
915 views
Can you decay to half an atom?
In school we are learning about half-life, and I was wondering if it is possible to decay to half an atom?
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1answer
490 views
Decomposition of AsH3
In German problems olympiad 2014, the solution says that decomposition of arsine is not a redox reaction. Why would that be? Shouldn't H turn from -1 to 0 and As from 3+ to 0?
$$\ce{2AsH3 -> 2As + ...
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1answer
286 views
Radioactivity of materials [closed]
Suppose that a raidoactive brick of an unknown element with a half-life of one year (dangerous stuff!) is left on a regular desk for a day. After the day has passed, the brick is removed. Does the ...
3
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0answers
140 views
Decomposition speed of ozone [closed]
Elementary reactions of decomposition of ozone with chlorine are as follows (substance with $^*$ is reaction intermediate):
\begin{align}
\ce{Cl2 + O3 &-> ClO^* + ClO2^*}\tag{1}\\
\ce{ClO2^* +...
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0answers
564 views
Rate order of decomposition of hydrogen peroxide
I have been having some troubles finding a source for my investigation. I am inverstigating the decomposition of hydrogen peroxide, which (according to my teacher/supervisor) is a second order ...
