Questions tagged [decomposition]
For questions about the decomposition of any chemical species, under any certain conditions.
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Promoting calcium carbonate decomposition [closed]
It is well-known that calcium carbonate undergoes thermal decomposition forming calcium oxide and $\ce{CO2}$. However, the reaction requires a lot of heat (approximately 840 °C). Is it possible to ...
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0answers
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Why is it that not all metals produce hydroxides when reacting with water? [duplicate]
I was taught, as a rule, that:
metals + water $\rightarrow$ metal hydroxide + hydrogen gas
$$\text{Na} + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{H}_2$$
However:
$$3\text{Fe} + 4\text{H}...
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1answer
53 views
How is this reaction not a decomposition reaction? And are all disproportionation reactions decomposition reactions?
When I asked my teacher whether all disproportionation reactions are decomposition reactions, he stated the following reaction:
$$ \ce{4 KClO3 -> 3 KClO4 + KCl} $$
and said that this isn't a ...
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49 views
What catalysts can be used to decompose nitrous oxide?
Constraints:
I'm going to need to use a lot of this stuff in various locations, so I'd prefer it not be expensive (leaving out things like platinum, palladium, and rhodium.)
While I don't believe I ...
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1answer
100 views
Do all metal nitrates give nitrogen dioxide on decomposition?
Some metal nitrates decompose to give nitrites: $\ce{2MNO3 -> 2MNO2 + O2}$
whereas some metal nitrates decompose to give $\ce{NO2}$. A possible reaction is $\ce{M(NO3)2 -> MO + NO2 + O2}$
Based ...
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52 views
Decomposition of Hydrogen Peroxide Catalysed by Potassium Iodide in Basic Solution
As part of my high school project, I had to measure the initial rate of decomposition of hydrogen peroxide catalysed by potassium iodide at different pHs. At higher pHs (alkaline conditions), I found ...
2
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0answers
54 views
Symbolic form of equilibrium constant for ammonium carbamate dissociation
$$\ce{NH2COONH4(s) <=> 2 NH3(g) + CO2(g)} \qquad K = \left(\frac{p(\ce{NH3})}{p^\circ}\right)^2\times\frac{p(\ce{CO2})}{p^\circ}$$
Assuming that you start this experiment with pure solid $\ce{...
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treating PLA (Polylactic acid) plastic to make it biodegradable
I am using PLA for 3D printing, and I know it does not degrade well in the wild. I would like to know if there is a chemical process I could use to treat it at home.
Specifically, I am looking for a ...
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2answers
416 views
Using the mass of calcium carbonate, what volume of carbon dioxide could theoretically be obtained if the reaction progressed to completion?
Using the mass of calcium carbonate $m(\ce{CaCO3}) = \pu{0.500 g}$, what volume of carbon dioxide $V(\ce{CO2})$ (in $\pu{mL})$ could theoretically be obtained if the reaction progressed to completion? ...
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1answer
49 views
How would one determine the temperature needed such that hydrogen peroxide will start to decompose? [closed]
Hydrogen peroxide decomposes at room temperature and so I was wondering what temperature is sufficient for this decomposition to occur.
Can someone explain how we can determine this? (theoretically or ...
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34 views
Strange Distillation Behavior
I was attempting a fractional distillation with 1mL water and 1mL propylene glycol, and I’ve been encountering strange behavior with the heating of the mixture. The heating curve shows strange “spikes”...
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2answers
374 views
How to neutralize the stink of decomposed fish?
Recently I discovered for myself an interesting way to easily produce home made plant fertilizer that is quite effective (tested myself on the plants). It's fish emulsion (so can be used also in a ...
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0answers
38 views
Software for modelling decomposition reactions
What are some good softwares that can model a decomposition reactions?
I have a reaction of H2O2 decomposing on metal exchange hexaaluminate catalyst. The catalyst is present in a packed bed thruster. ...
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0answers
44 views
Fate of compounds after radioactive decay [duplicate]
Let us say there is a $\ce{CO2}$ molecule containing $\ce{^{14}C}$ isotope. $\ce{^{14}C}$ undergoes decay to form $\ce{^{14}N}$. What happens to the molecule?Does it form $\ce{NO2}$? How are the ...
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What are the most potent hydrogen peroxide decomposition catalysts available to an amateur? [closed]
Some months ago I was playing with $60\,\%$ $\ce{H2O2}$ and unknowingly I used a silver spoon to transfer the liquid from a container, and the peroxide immediately started bubbling (it did look and ...
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33 views
How can I analytically calculate the rate of thermal decomposition of calcium carbonate?
I am a first-time poster on Chemistry StackExchange, and not much of a chemist.
I'm trying to determine the rate of thermal decomposition (in mol/s) of calcium carbonate ($\ce{CaCO3}$) at various ...
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1answer
42 views
Basic Chemistry: Carbon Dioxide Formation Unsure about Reaction [closed]
I have the following question description:
Consider a gas composed of $\ce{CO_2}$, $\ce{CO}$, $\ce{O_2}$ and $\ce{O}$ with 1 $\ce{C}$ nuclei for every 2 $\ce{O}$
nuclei.
I am trying to write ...
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1answer
245 views
Risks from overheated phenolphthalein in green/orange silica gel drying
Recently I tried to dry out some indicating silica gel. When I googled, I found advice on line saying that it should be heated to 150 C and that such was a standard procedure, so I popped it into the ...
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1answer
888 views
Half-life and shelf-life of second-order reaction
For integrated rate laws, I have attempted to find the shelf-life and half-life of second-order reaction:
However, the answers I have obtained (which are labelled with a red cross) are very different ...
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1answer
1k views
Can Aluminum Hydroxide (Al(OH)3) be heated to it's melting temperature before decomposing?
On the wikipedia page for aluminum hydroxide the listed melting point is 300 °C (572 °F), but in the same page it states that aluminum hydroxide decomposes at only 180 °C (356 °F). Can aluminum ...
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2answers
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Diluting 4 % NaOCl to get a 1 % solution
Assuming that one has a 1 litre bottle of liquid bleach containing $4~\%$ sodium hypochlorite. If I wish to dilute it down to $1~\%$ sodium hypochlorite (to use as disinfectant), would adding 3 litres ...
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0answers
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Long Term Storage of D-Cell Battery
I plan to store D-cell batteries in a winter home. The shelf-life is finite: is there any reason not to freeze or refridgerate the batteries to extend the shelf life?
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Algae Cultivation Using Polyethylene Film Reactor Vessel Floating In Pool with Algicidal ClO2 Concentration
I'm attempting to grow chlorella algae in a polyethylene film bag (which contains the growth medium) submerged in a temperature-moderating, above-ground swimming pool. This presents a challenge in ...
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1answer
616 views
How can we tell if a salt will melt or decompose?
Take $\rm NaCl$ for instance, a salt that will melt when it reaches its melting point, and compare it with $\rm NH_4NO_3$, a salt that doesn't melt, but instead decomposes to $\rm N_2O$ and $\rm H_2O$ ...
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2answers
477 views
What does HClO2 aqueous solution decompose to in an open environment? [closed]
I looked up the decompositions of diluted $\ce{HClO2}$ aqueous solution (used in a disinfectant) to know if it is safe to use on some substances, such as metal, wood, leather or skin. However, the ...
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1answer
339 views
What is the "mechanism" of the decomposition of hydrogen peroxide?
In my classwork on the decomposition reaction of hydrogen peroxide by catalase, I wrote the following equation:
$$\ce{2H2O2 -> 2H2O + O2}$$
However, my teacher said that I should go further in ...
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2answers
176 views
Thermal Decomposition of Sulfur Hexafluoride
What is the thermal decomposition temperature for $\ce{SF6}?$ I've heard it decomposes into $\ce{F2}$ and $\ce{SF4}$ only to decompose further into $\ce{S2}$ and $\ce{F2},$ but I haven't found much on ...
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2answers
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Preparation of Barium Hexaaluminate using co-precipitation reaction mechanism
I am preparing Barium Hexaaluminate (BHA) using $\ce{Ba(NO3)2, Al(NO3)3}$, and $\ce{(NH4)2CO3}$. For $\pu{1 mol}$ of each $\ce{Ba(NO3)2}$ and $\ce{Al(NO3)4}$, I am using $\pu{1.5 mol}$ of $\ce{(NH4)...
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1answer
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When MgCl₂ · nH₂O is heated to the boiling point of H₂O
When magnesium chloride hydrate is heated, does $\ce{Mg(OH)2}$ form or what? I'm curious, because Wikipedia says that it decomposes to release $\ce{HCl}$ gas.
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Why are ions much more efficient than electrons at beam-induced deposition?
I have recently been reading about electron beam induced deposition and ion beam deposition. The idea is to send a high energy (5-30 kV) beam of electrons/ions focused down to a spot on a material and ...
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0answers
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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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0answers
226 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
636 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
449 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. Silver nitrate
...
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1answer
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Thermal decomposition of K2CO3
$\ce{K2CO3}$ doesn't boil. It thermally decomposes at $\pu{1200 ^\circ C}$. However, I find conflicting information online about this. Roughly what I have found say three inconsistent things:
It ...
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2answers
505 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
98 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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3answers
159 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 = 0.0142$$
...
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2answers
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What is the most convenient way to prepare ferrous oxide (FeO) in the laboratory?
The Wikipedia page for ferrous oxide states that $\ce{FeO}$ can be prepared by the thermal decomposition of iron(II) oxalate, with the following reaction:
$$\ce{FeC2O4 → FeO + CO2 + CO}$$
And that ...
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votes
2answers
315 views
What is the fate of sulfur in cysteine when it participates in gluconeogenesis?
Amino acids can be broken down to yield pyruvate, which in turn can be used to construct glucose molecule in the process of gluconeogenesis. What happens to the sulfur atom in the amino acid cysteine ...
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1answer
71 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
265 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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0answers
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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 ...
2
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1answer
612 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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1answer
2k views
Hydrogen peroxide and glycerol combination
Is the mixing of store-grade hydrogen peroxide 3% and glycerol in the ratio of 1:2 (V/V) at room temperature affecting the decomposition rate of hydrogen peroxide?
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2answers
7k 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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2answers
528 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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0answers
214 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 ...
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1answer
784 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 + ?}$$
...
4
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1answer
247 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 ...
