Questions tagged [decomposition]
For questions about the decomposition of any chemical species, under any certain conditions.
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questions
2
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1answer
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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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3answers
85 views
$K_c$ 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:
$$\ce{2 NOBr(g) <=> 2 NO(g) + Br2(g)} \qquad K = 0....
6
votes
2answers
902 views
What is the most convenient way to prepare ferrous oxide (FeO) in the laboratory?
The Wikipedia page for ferrous oxide states that $\ce{FeO}$ can be prepared by the thermal decomposition of iron(II) oxalate, with the following reaction:
$$\ce{FeC2O4 → FeO + CO2 + CO}$$
And that ...
0
votes
1answer
65 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 ...
2
votes
1answer
38 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 ...
1
vote
0answers
19 views
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 ...
0
votes
1answer
99 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 ...
0
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1answer
111 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 ...
6
votes
2answers
87 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}$...
2
votes
0answers
83 views
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 ...
1
vote
1answer
31 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 + ?}$$
...
3
votes
1answer
63 views
What (simple) household chemicals react with oxygen?
I'm interested in making a small "preservation chamber" that I can basically use to store objects without the presence of oxygen. I have a resealable stainless steel canister and the plan is pretty ...
1
vote
1answer
124 views
Thermal decomposition of ester [closed]
I have a clear liquid with a faint sweet smell. I know this compound contains an aromatic group and an ester. However, something strange happens when I try to distill it - it forms a white solid. I ...
0
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0answers
27 views
Decomposition of Sugar Temperature
I am perplexed by information on the internet about the sugar raffinose.
The melting point of raffinose is 244.4°F
The boiling point of raffinose is 1,623°F
I can't find the temperature at which it ...
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votes
1answer
58 views
Determining the formula of tin(II) chloride hydrate [closed]
$\pu{1.20 g}$ of hydrated tin chloride decompose to form $\pu{1.01 g}$ of anhydrous tin chloride on heating. Calculate the value of $x$ given
$$\ce{SnCl2.xH2O -> SnCl2 + x H2O}$$
I done it ...
0
votes
2answers
190 views
The thermal decomposition of NH4Cl [closed]
When you heat $\ce{NH4Cl}$ it decomposes into $\ce{NH3 + HCl}$ gases. My question is why does it decompose into ammonia and hydrogen chloride gases on the molecular level. Is it because in the $\ce{N-(...
2
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0answers
76 views
Mechanism for removal of pesticides from fruit by sodium bicarbonate
When Googling around for methods to remove pesticides from fruits and vegetables, a study commonly referred to from some news sites (e.g. here and here ) is one where soaking apples in a sodium ...
3
votes
1answer
91 views
Hydrate decomposition equation steps
When a hydrate decomposes it loses water molecules in steps.
Does each step have a chemical equation?
If so is the following equations for decomposition of cupric sulfate hydrate correct?
$$
\begin{...
2
votes
2answers
179 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 ...
5
votes
1answer
112 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
142 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 ...
0
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1answer
73 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 ...
7
votes
1answer
515 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 $$\...
7
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0answers
93 views
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 ...
4
votes
1answer
80 views
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!
0
votes
2answers
48 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 ...
5
votes
1answer
81 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}$) $...
18
votes
2answers
2k views
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 ...
5
votes
1answer
214 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 ...
2
votes
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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0answers
19 views
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 ...
3
votes
0answers
55 views
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
2k 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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0answers
17 views
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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vote
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?
3
votes
0answers
235 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
196 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 ...
3
votes
1answer
2k 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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votes
1answer
414 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}$$
The initial ...
0
votes
3answers
822 views
Can you decay to half an atom?
In school we are learning about half-life, and I was wondering if it is possible to decay to half an atom?
2
votes
1answer
413 views
Decomposition of AsH3
In German problems olympiad 2014, the solution says that decomposition of arsine is not a redox reaction. Why would that be? Shouldn't H turn from -1 to 0 and As from 3+ to 0?
$$\ce{2AsH3 -> 2As + ...
11
votes
1answer
285 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
votes
0answers
126 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^* +...
2
votes
0answers
533 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 ...
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2answers
3k views
Thermal decomposition of magnesium bicarbonate
I was trying to solve a problem from a regional contest where it was a mixture of bicarbonates of $\ce{Na}$ and $\ce{Mg}$ which was put at high temperature. What are the reactions of decomposition?
I'...
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votes
1answer
13k views
What reaction happens when carboxylic acids are treated with calcium hydroxide and distilled? [closed]
What reaction takes place when $\ce{Ca(OH)2}$ reacts with $\ce{R-COOH}$? What is obtained after distillation?
3
votes
2answers
1k views
Why does calcium carbonate decompose in sulphuric acid?
Here's the reaction:
$\ce{H2SO4(aq) + CaCO3(s) -> CaSO4(s) + H2O(l) + CO2(g)}$
I don't understand why calcium carbonate decomposes in sulphuric acid. It's not soluble in water. I could ...
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votes
3answers
6k views
Why doesn't CaO decompose into Ca and O2?
Many metal oxides decompose into the free metal and oxygen gas at high temperatures, but why doesn't $\ce{CaO}$ do that? What happens to $\ce{CaO}$ at high temperatures?
This is from problem 2 of the ...
1
vote
1answer
391 views
Sulfur from pyrite roasting process
I'm solving a quantitative problem involving the process of making oleum from pyrite.
The problem specifies that, at the end of the reaction, we find sulfur which does not come from the impurities ...
1
vote
2answers
134 views
What type of reaction is the reaction between an acid and a carbonate?
Consider the following reaction:
$$\ce{2HCl + Na2CO3 -> 2NaCl + H2O + CO2}$$
Is this a double displacement reaction or a decomposition reaction?
