Chemical Engineering - Chemical Engineering Basics - Discussion

1. 

Which one of the following is incombustible ?

[A]. H2
[B]. CCl4
[C]. C2H2
[D]. S

Answer: Option B

Explanation:

No answer description available for this question.

Sundar said: (Sep 21, 2012)  
Incombustible - Not capable of igniting and burning.

Olamigoke said: (Sep 26, 2012)  
Is one of the example of Halons, which is fire extinguisher.

Vinnu said: (Nov 22, 2012)  
CCl4 hasn't capable of igniting, burning.

Chandrashekhar said: (Jan 2, 2013)  
It is used as dry cleaning solvent and refrigerent.

Symon Foyez said: (Jan 25, 2013)  
H2, C2H2 and S all undergoes combustion reaction with O2. CCl4 is not flammable, it is known as halon used in fire extinguishers.

Geetha said: (Aug 6, 2013)  
I can't understand clearly, why it is incombustible? can you please explain about it?

Somya said: (Sep 24, 2013)  
Because CCl4 does not combustible reaction so not use fire extinguisher.

Kingsuk Das said: (Oct 29, 2013)  
The structure of CCl4 is tetrahedral which is geometrically stable and other such as C2H2 has unsaturation moreover S has lone pair electrons in its hybrid d orbitals and H2 also has 1s bonding which the combustible heat energy is evident to break the relevant bond energy in comparison to CCl4

Asifa said: (Jan 27, 2014)  
Give me few other example apart from ccl4 which is incombustible.

Somdev Ghosh said: (Feb 12, 2014)  
Combustion means reaction with oxygen or burning in layman's term.

Hypothetically, for combustion of CCl4 , the following reaction would have occurred :

CCl4 + O2 -> CO2 + 2 Cl2

For feasibility of any reaction, the sum of bond energy of all the products should be less than sum of bond energy of all the reactants.

In this case, breaking of O-O, and four C-Cl bonds require more energy than forming two C-O and two Cl-Cl bonds. Hence, CCl4 does not react with Oxygen and is incombustible

Kemelo said: (Feb 14, 2014)  
CCl4 is noncombustible because it is a stable compound.

Ragini Reddy said: (Mar 4, 2014)  
Because it is used as fire extinguisher.

Gajendra Inwati said: (Mar 14, 2014)  
CCl4 is highly stable due to equal electronegativity of chloride,

So C-atom experience equal effect.

Rohit Singh Tariyal said: (Mar 29, 2014)  
Incompressible means. Those fluid which not affected by the temperature and pressure. This cause all liquid have this property. And ccl4 is also a liquid.

Rajesh Dubba said: (May 6, 2014)  
Actually according to the organic chemistry, CCl4 cannot achieve any type of burning or charring in the presence of atmosphere.

So, it cannot control the process of combustion.

Hanumanthu said: (Aug 27, 2014)  
Gases are compressible components.

Liquids are incompressible components.

Mounika said: (Dec 8, 2014)  
Can you explain the actual reason behind it?

Remington said: (Dec 23, 2014)  
Based on FCBOIS activity series. It can't replace Cl in CCl4, thus, combustion will not occur.

Snehal said: (Mar 13, 2015)  
It does not burn/explode.

Pawan Kumar said: (May 23, 2015)  
CCl4+O2->CO2+2Cl2.

Raman said: (Jul 19, 2015)  
Can you point out other incombustible gases?

Jose Nishanth said: (Sep 4, 2015)  
CCL4 has not have the capability to burn. Because when it was heated it forms the more amount of CO2.

Suneel Murtaza said: (Jan 11, 2016)  
Cleaning, fire extinguisher element.

Suneel Mutaza said: (Jan 11, 2016)  
It is colorless liquid, fire extinguisher, cleaning agent in industry.

Maitreyi said: (Sep 2, 2016)  
Please, tell me any other example for non-combustible element.

M Lokesh said: (Jan 5, 2017)  
I don't understand. Someone explain me.

Sharan said: (Feb 17, 2017)  
Incombustible Not combustible; not capable of being burned, decomposed, or consumed by fire; un-inflammable. As asbestos is an incombustible substance.

Carbon dioxide is an incombustible gas.

Ganesh said: (May 25, 2017)  
CCl4 used as a fire extinguisher.

Panchanan Panda said: (Jun 3, 2017)  
Carbon tetrachloride has a high degree of liver toxicity, so it is banned in consumer products in the United States. Historically, it was used as a refrigerant, a fire suppression agent, and a cleaning solvent like Carbon Tetrachloride, it saw use as a refrigerant and cleaning solvent.

Rajendra Kotkar said: (Nov 20, 2017)  
CCl4 is used as fire extinguisher.

S Kannathasan said: (Dec 10, 2017)  
CCl4 used as fire extinguisher.

Anvesh said: (Feb 17, 2018)  
Consider the combustion of a simple molecule methane CH4:

CH4 + 2O2 = CO2 + 2H2O.

However, if we consider a similar molecule CCl4, carbon tetrachloride, which is just a replacement of H by Cl in methane, is incombustible.

This can be explained by observing the reaction above. CH4 burns to give CO2 and Water. Hydrogen being an electropositive element joins oxygen quickly.

However, chlorine being an electronegative element would like to connect to an electropositive element carbon, as it can pull the electron pair closer to itself!

Getting Cl in +1 state is difficult.

So the reaction
CCl4 + 2O2 = CO2 + 2Cl2O is least probable.

Because it doesn't combust, it was used as a fire extinguisher under the name pyrene.

Whajah Bernard said: (May 14, 2019)  
CCl4 is incombustible because the combustion products will have higher energy content than that of the reactants. For combustion to take place, the products should contain stable compounds (lower energy content) eg. H2O, CO2 etc. Than that of the reactants. CCl4 is very stable due to its structure.

Bhushan Meshram said: (Sep 23, 2019)  
Chlorine being an electronegative element, would like to connect to an electropositive element carbon, as it can pull the electron pair closer to itself.

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