Questions tagged [carbon-allotropes]

This tag should be applied to questions about the various allotropes of carbon and their physical or chemical properties. Most important modifications are diamond, graphite, fullerenes, graphene and nanotubes.

5
votes
1answer
37 views

What happens to the carbon in carbon steel when it rusts?

Carbon steel is iron containing some carbon in various forms of iron carbide. When it rusts (oxidises), the iron becomes part of all kinds of crystalline and amorphous iron oxides and hydroxides, ...
1
vote
1answer
29 views

What molecules are produced in carbon arc lamp and how do they produce light?

I am curious about the chemistry of the arc lamp (an indirectly for the incandescent bulbs) thus I would like to ask the following. It is a common understanding that the electrons pushed inside an ...
8
votes
0answers
60 views

How is the aromaticity in graphene different from the aromaticity in benzene?

The web page Aromaticity in Graphene and other 2-D Systems begins: I. Graphene While the σ-bonding in graphene is assumed to be a rigid honeycomb framework built out of two-center two-...
3
votes
1answer
75 views

Home-grown diamond using CVD

I want to make a diamond at home using chemical vapor deposition (CVD). If I use a metal chamber filled with methane and hydrogen gas and heated with a microwave oven oscillator element, will the ...
0
votes
0answers
28 views

Why is high pressure and high temperature favourable for the formation of diamond? [duplicate]

Graphite can be converted to diamond and this conversion is favourable under high pressure and high temperature. Is there a reason for this from the point of view of "Le Chatelier's Principle"? I ...
3
votes
0answers
48 views

Possibility of non-hexagonal graphene

I understand that monolayer carbon naturally forms in a regular hexagonal tiling. Is it, however, possible (if difficult) to form carbon monolayers of a different structure? A 3-12-12 tiling, for ...
0
votes
0answers
30 views

Can CO2 Be Electrochemically Reduced to Carbon Nanotubes?

Mitigation of CO2 as greenhouse gas has driven increasing investigation of its chemical reduction. The 2018 paper "Recent Progress in the Theoretical Investigation of Electrocatalytic Reduction of CO2"...
4
votes
3answers
247 views

Why is graphite brittle?

Carbon exists in more than one allotropic forms, and the allotropes have different physical properties due to different arrangement of atoms. I am going to compare their hardness for now. Below is ...
0
votes
1answer
102 views

Why does diamond have no molecular formula?

Why does diamond have no molecular formula, while buckminsterfullerene does have it, despite both being allotropes of the same element?
5
votes
2answers
176 views

Aetiology of the word “fullerene” in Chemistry

I am a mathematician and not a chemist, and I am trying to understand the historical relationship and current usage of the word "fullerene" across Mathematics and Chemistry. I apologise in advance ...
2
votes
1answer
108 views

Do molecules containing only carbon exist?

Why doesnt carbon forms bonds with itself to form a molecule. Carbon shows the property of catenation then why doesnt it form a cyclic molecule as : ...
39
votes
4answers
16k views

Why can a diamond be broken using a hammer if it's the hardest natural substance known?

I've heard that diamond is the hardest natural known material but, on Google search, I found that it can easily be broken by a hammer as it's not tough. So, what is difference between hardness ...
0
votes
2answers
239 views

Calling Diamond an element?

Is it scientifically correct to call Diamond an element? Carbon has a wide range of allotropes, so would it be correct to actually just call graphite, diamond etc an element. For that matter, could we ...
3
votes
1answer
80 views

Why does it require so much pressure to create diamonds?

Why does it require so much energy/pressure to create diamonds, yet with silicon it is very easy and (I believe) naturally occurs in a "diamond" structure, i.e. where each atom is covalently bonded to ...
0
votes
1answer
657 views

Graphite: Thermal and electrical conductivity

I recently encounter this question: Compare, while providing an explanation, the thermal and electrical conductivity of graphite to that of diamond. Provided answer: Graphite conducts electricity(...
0
votes
0answers
13 views

How is the covalency of terminal carbons of a diamond satisfied? [duplicate]

Are the terminal carbons of the diamond lattice remain bonded to some element like hydrogen? Or, is it that they don't achieve octate in their outer shell?
2
votes
0answers
25 views

Existence of tesserane and it's properties

Could there exist an allotrope of carbon, $\ce{C16}$ where the overall shape of the molecule is a three dimensional representation of a tesseract? And what are its (predicted if unknown/unsynthesised) ...
1
vote
2answers
148 views

What dangers/risks are there in the production of carbon subnitride?

I was reading that carbon subnitride or Dicyanoacetylene has one of the hottest flames when used as a fuel, but it also is unstable and can explode easily into carbon powder (no specifics on cause). ...
1
vote
0answers
72 views

What would happen to a diamond in the presence of oxygen and elevated temperature and how fast?

Let's say I have a $\pu{1cm^3}$ diamond and I put it into an oven where the temperature is about $\pu{ 400°C}$. We all know that diamond oxidizes. Would it evaporate or turn into graphite? If so, ...
10
votes
2answers
3k views

Why do diamond and graphite have different structures, when they are both composed of carbon?

Both diamond and graphite are covalent networks and are both made entirely from carbon, but why does diamond have a three dimensional network of strong covalent bonds which makes it hard, whereas ...
2
votes
1answer
86 views

What causes the anti-siccative effect of soot (amorphous carbon) as a pigment in oil paints?

Oil paint containing carbon black (soot, charcoal) pigment is known to polymerize ("dry") a lot slower than if it has other pigments. I understand this is not just due to the absence of pigments which ...
3
votes
0answers
137 views

Is this a viable method for graphene production?

In a cup of warm water add sugar until it no longer dissolves then add a few spoonfuls more of sugar. Drop in a small amount of graphite powder into the sugar water mixture. Stir it up well. There ...
1
vote
0answers
31 views

Extraction of Activated Carbon from Lignin

I'm currently working on a research project which involves the extraction of activated carbon from lignin. I'm already aware of the method of preparation using an alkali along with lignin products but ...
2
votes
1answer
65 views

Diamonds into protective barrier

Theoretically, is it possible to make a large, transparent piece of armor or a shield from a diamond? Say, a piece of the said armor with a size $7^\prime \times 7^\prime \times 6^{\prime\prime}$? ...
8
votes
2answers
776 views

How to tell between carbon powder or graphite powder?

I have a black powder that I cannot reliably tell just by looking or touching whether it is graphite powder or charcoal powder. Are there any simple tests that I can perform to tell whether it is one ...
1
vote
1answer
98 views

How fast does the diamond lose the atoms at sunlight?

recently I've read that the diamonds lose their atoms at sunlight on the surface. Would you be able to explain me how fast is the rate of this process? Does the diamond lose the atoms each time when ...
0
votes
3answers
1k views

Is graphene a combustible material?

Various sources such as https://news.ycombinator.com/item?id=7679154 speculate that graphene will combust at higher temperatures. Is this true? Is the flash point/ temperature of combustion for ...
13
votes
1answer
3k views

Why is the buckminsterfullerene the purest form of carbon?

Other websites say that $\ce{C60}$ doesn't have surface bonds that are attracted by other atoms as in graphite and diamond. I understand that graphite may be attracted by other atoms because of its ...
2
votes
0answers
155 views

Can activated charcoal retain adsorbtion properties even when submerged in liquids?

This is following a question on Skeptics Stackexchange, where apparently medical science claims that activated charcoal can adsorb poison when ingested. One of the members posted a related question on ...
1
vote
1answer
87 views

Reacting carbon dioxide with magnesium in ribbon form

My experiment involves a reaction of magnesium in ribbon form with that of carbon dioxide. I know that the product shall be magnesium oxide (white powder) and carbon (black powder) but I do not know ...
10
votes
1answer
278 views

Why are isotopically pure diamonds 50% more thermally conductive than other diamonds?

A laboratory grown type-IIa diamond (no nitrogen defects) has a lambda of $\pu{1800-2200 W/mK}$, but an isotopically pure diamond of $\ce{^{12}C}$ can have up to $\pu{3320 W/mK}$. Why are $\ce{^{12}C}...
12
votes
1answer
1k views

Can diamond undergo a self sustaining combustion reaction all the way to carbon dioxide?

I know charcoal can smoulder in an incomplete combustion to produce carbon monoxide so I assume diamond also can. If it's heated to a sufficiently high temperature, will the reaction produce enough ...
-3
votes
2answers
3k views

Why does Graphene have a higher melting point than Diamond?

I'm not 100% sure about this, so I just wanted to double-check. I think it has something to do with each carbon atom in Graphene having a delocalized electron and this creates carbon ions that can ...
4
votes
1answer
1k views

If graphite's just a huge polymer of benzene why isn't it an aromatic compound (polymer?)

My teacher had once told me that graphite was just an insanely huge polymer of benzene (Those weren't his exact words but the gist). Today While we were studying aromaticity in organic compounds we ...
1
vote
2answers
8k views

Why is fullerene 60 an insulator while graphite is a conductor?

Graphite is good conductor of electricity because one carbon atom is bonded only three carbon atoms, which enables the presence of free electrons. In fullerene 60 the carbon atoms are also bonded to ...
6
votes
1answer
128 views

How are atoms encapsulated in buckminsterfullerene molecules?

According to nature.com, buckminsterfullerene molecules (bucky balls) can be formed by vaporizing graphite by saturating it with laser irradiation. I haven't entirely understood why the carbon forms ...
1
vote
2answers
1k views

Is it possible to melt a diamond? [duplicate]

I am school student. In my school text book there is a fact about diamond. That is Each carbon atom is covalently bonded to four other carbon atoms. A lot of energy is needed to separate the atoms ...
0
votes
1answer
1k views

How is graphite a covalent solid?

I know it is covalent because there are covalent bonds between atoms of carbon in the same plane. But there are Van der Waals interactions between different planes. Isn't this a feature of molecular ...
8
votes
1answer
334 views

Why can't one make C60 with a combination of hexagons and heptagons?

$\ce{C60}$ has a pentagon-hexagon system. Why can't one make it from a hexagon-heptagon system, or a pentagon-heptagon system for that matter?
0
votes
0answers
100 views

Can diamond be melted in a thermite reaction? [duplicate]

My book says A thermite reaction is an exothermic reaction, it releases a large amount of heat so that temperature increases up to 3500 °C. On the other hand, it says the melting point of diamond ...
1
vote
0answers
108 views

Chemical shifts seen during XPS

When in X-ray Photoelectron spectroscopy, an Si $2p$ peak is defined or a C $1s$ peak is defined at a certain binding energy, how is it done? I presume it is done from mono-crystalline Si but even in ...
3
votes
2answers
2k views

sp2 hybridized carbon versus sp3 hybridized silicon

Carbon's most commonly found allotrope is graphite/soot/fullerene/carbon nanotubes which are all $\mathrm{sp^2}$ hybridized forms of it, while silicon being its first periodic twin is mostly found in ...
16
votes
1answer
387 views

Band gap of fullerenes

From what I have read about fullerenes, the lower fullerenes like $\ce{C60}$ or $\ce{C70}$ have higher bandgaps around 3.5 eV or such, while the higher fullerenes have much smaller bandgaps of the ...
1
vote
0answers
458 views

Total number of carbon atoms in buckminsterfullerene

From what I read, buckminsterfullerene is composed of 60 carbon atoms, $\ce{C_{60}}$ and it is made up of 20 hexagons and 12 pentagons. So, I decided to do a back of the hand calculation with the ...
2
votes
1answer
729 views

Delocalised electron in graphite

I have a question regarding the delocalised electron in graphite. There has been conflicting information between books. Some books said the delocalised electron in graphite exists $\bf{between}$ ...
27
votes
3answers
3k views

Are graphite and hexagonal boron nitride aromatic

Are graphite and hexagonal boron nitride aromatic? Graphite has a planar network of 6-membered rings with each carbon connected to three other carbons. Since the valency of carbon is not satisfied, ...
0
votes
1answer
3k views

How can one make graphene cables?

You might have seen in the short 2 minute video here: billionsinchange.com/solutions/limitless-energy that the Billionaire Founder (net worth $4 billion) Manoj Bhargava talks about creating cables ...
5
votes
2answers
640 views

What is a 'corona phase'?

What is a 'corona phase'? I have come across this term in several papers, including this one but all I have found concerning its definition is: [...] synthetic heteropolymers, once constrained ...
12
votes
1answer
575 views

How small is the smallest known carbon ring containing only double bonds?

How small is the smallest known carbon ring containing only double bonds? The stress from the double bonds makes small rings impossible to make something like cyclohexahexaene so I want to know how ...
18
votes
1answer
325 views

What is Q-carbon? Does it exist?

Glowing press releases and news articles in 2015 proclaimed a new allotrope of carbon. However, even the journal article is light on chemical detail (e.g. no structural formula). What is its bond ...