Gasoline structure, Characteristics : 25 Facts To Know

In this article, we learn about a natural fuel like gasoline and its structure, property, and many more facts.

Gasoline structure is a hydrocarbon compound, so it is an organic molecule. The general formula of gasoline is CnH2n+2. So, gasoline is an alkane molecule. Petrol is one example of gasoline. Gasoline structure is as similar to alkane structure. Higher-order alkane mainly from pentane to decane or so on are liquids and the mixture of them is used as gasoline.

Gasoline is an extremely flammable molecule. It has a low flash point of -230 C. like all other liquid hydrocarbons gasoline burns in a limited range of its vapor phase. It is highly volatile so it is dangerous if its source of ignition is present.

Some important facts about gasoline

The molecular weight of gasoline is initially 108 g/mol. It depends upon the higher-order alkanes which should involve. The color of the gasoline structure is mainly colorless to pale brown or pink, it also depends on which alkane is involved in the composition.

Initially, the boiling point is 390C after 105 distillation the boiling point becomes 600C, after 50% and 90% distillation the boiling point increases to 1100 C and 1700C respectively. Finally, the boiling point will be 2040C.

The density of the gasoline structure is 0.7 g/cm3. The odor is gasoline odor and the physical state of the gasoline structure is liquid.

Now we discuss the composition by the percentage of gasoline structure,

components                 percentage composition                       Other possible Components

n-alkanes                                                                                           Octane enhancers

C5                                3.0                                           N,N-dialkylphenylenediamines            

C6                                11.6                                         methyl t-butyl ether (MTBE)    

C7                                1.2                                                       t-butyl alcohol (TBA)

C9                                0.7                                                       ethanol

C10-C13                         0.8                                                       methanol

Total of n-alkanes       17.3                                                     antioxidants

                                                                                    2.6-dialkyl and 2,4,6-trialkylphenols

Branched alkanes

C4                                2.2                               butylated methyl, ethyl and dimethyl phenols

C5                                15.1                             triethylene tetramine di(monononylphenolate)

C6                                8.0                                           metal deactivators

C7                                1.9                                           N,N-disalicylidene-1,2-ethanediamine

C8                                1.8                                           N,N-disalicylidene-propanediamine

C9                                2.1                               N,N-disalicylidene-cyclohexanediamine

C10-C13                         1.0                               disalicylidene-N-methyl-dipropylene-triamine

Total of branched       32.0                                         ignition controllers

                                                                                    tri-O-cresylphophate (TOCp)

Cycloalkanes                                                               icing inhibitors

C6                                3.0                                           isopropyl alcohol                     

C7                                1.4                                           detergents/dispersants

C8                                0.6                                           alkylamine phosphates

Total of cycloalkanes    5.0                                           poly-isobutene amines

                                                                                    long-chain alkyl phenols

olefins                                                                          long chain alcohols

C6                                1.8                                           long chain carboxylic acids

Total of olefins 1.8                                                          long chain amines

Aromatics                                                                   Corrosion inhibitors

Benezene                     3.2                                           carboxylic acid

Toluene                       4.8                                           phosphoric acid

Xylenes                       6.6                                           sulfonic acid

Ethylbenzene               1.4

C3-benzenes                 4.2

C4-benzenes                 7.6

Others                          2.7

Total aromatics            30.5

1.    What is a gasoline structure?

Gasoline is the combination of different higher-order alkanes. So, the gasoline structure is also mixed with different compounds. Mainly C8H18.

gasoline structure
Gasoline Structure

Sometimes the gasoline structure will be 2,2,4-trimethylpentane, so here also 8 carbon atoms are present. So, the general gasoline formula can be C8H18. We know C-C single bond rotation is possible due to lower barrier energy, so they can rearrange by rotating the bond and forming different structures, they are chain isomers.

2.    How to draw a Gasoline structure?

Gasoline structure is nothing but an octave structure. So first we try to draw the method of octane structure. By drawing the octane structure we can draw the gasoline structure which has the molecular formula C8H18.

Octane Skeleton

To draw the gasoline structure or any alkanes we should keep some points in our mind.

Step 1– First we draw the number of C atoms, which mentions in the following manner,

  1. Meth
  2. Eth
  3. Prop
  4. But
  5. Pen
  6. Hex
  7. hept
  8. Oct and so on.

Step 2- Gasoline structure is made by alkane, so here only a single bond is allowed. Now we connect all the c atoms via single bonds only.

Step 3 – Now the valency of carbon atoms is satisfied by adding a respective number of H atoms. If there is any functional group is present then it should be placed at the respective position.

Step 4– now we numbering all C atoms from the left side and kept in mind that the functional group gets the least number or begins the number.

3.    Is gasoline covalent or ionic?

From the gasoline structure, it is evident that there is no ionic part is found in the gasoline structure. Gasoline structure is the skeleton of C and H atoms and both are not ionic in nature. So, the gasoline structure is not ionic.

Gasoline is nothing but a hydrocarbon, which is a special alkane. There are only H and C atoms are present, C and H both do not have ionic potential to polarize the other part or they cannot be ionizable to form an ionic bond, so the gasoline structure is a purely covalent molecule.

4.    Is gasoline a hydrocarbon?

Yes, the gasoline structure is a hydrocarbon. The molecules which form from H and C atoms are only called hydrocarbons. All the organic molecules are hydrocarbons.

Not always hydrocarbon contains only C and H atoms, they should contain other hetero atoms like O, N, S, etc along with H and C. actually, if a skeleton of a molecule is made by C and H then the molecule is called as a hydrocarbon. The gasoline structure is C8H18 which is an alkane molecule named octane. The skeleton of the gasoline structure is made of only C and H atoms, so gasoline is a hydrocarbon.

5.    Is gasoline acidic or basic?

It says very difficultly for a hydrocarbon to be acidic or basic because there is an option for pH. After all, most all hydrocarbons are insoluble in water. pH is applicable when a molecule is soluble in water and the aqueous solution gives the pH value.

The gasoline structure is made of hydrocarbon it is an alkane. There is no electronegative atom present in the molecule. The electronegativity of H and C atoms are similar so there is no factor present to make the molecule either acidic or basic. So, we cannot predict the acidic or basic nature of gasoline.

6.    Is gasoline made from oil?

If there is no mention of oil, then we can say that gasoline is not made from oil. Because oil is a combination fatty acid and there is no mechanism to form gasoline from the acid molecule. Because gasoline is an alkane.

The gasoline structure is only a hydrocarbon, so there is no chance to produce the alkane from oil. Actually, gasoline is formed from crude oil which is extracted from the earth’s crust, but from normal oil, we cannot synthesize the gasoline structure.

7.    Is gasoline made from crude oil?

Gasoline is made from crude oil and other petroleum liquids. These petroleum or crude oil go through three processes to get gasoline structure they are

  • Distillation
  • Conversion
  • Blending

Distillation – In this method, the crude oil is heated and then separated. This process is done in the crude towers or vacuum towers. Modern separation techniques are involved in piping crude oil through hot blast furnaces. The resulting liquids and vapors are discharged into units called distillation units. All the refineries where gasoline is made from crude oil have atmospheric distillation units. But the more complex refineries used vacuum distillation units.

Gasoline is one of the light fractions which is liquefied in the refinery gases, then vaporized and rises to the top of the tower, where they condensed and again back to liquid.

Conversion In this method company adds different kinds of chemicals, catalyst and it gets pressure and heat to the oil in the vessels that are called hydro-cookers or fluidized catalytic crackers. In this process, large hydrocarbons will be cracked into small ones.

After distillation, higher-value products such as gasoline can be processed further into lighter. Here fractions are transformed from the distillation units to streams which are intermediate components, that eventually become finishing the products.

There are two processes in conversion one is alkylation and the other is reforming.

In alkylation, gasoline components are made by combining some of the gaseous byproducts which are formed during the cracking process.

The reforming process uses heat and moderate pressure and also the uses of catalysts to turn Naptha, which is a light and relatively low vale fraction, into gasoline components which is high octane value.

Blending – this process is done to get various types of products that are usable as engine fuel. Here octane level, vapor pressure ratings, and other special considerations will be done to determine the gasoline blend.

The higher-order chains from octane C8H18 to C15 are blended from gasoline. All of them can be vaporized at a temperature that is below the boiling point of water and for this reason, if gasoline is spilled on the ground it evaporates very fast. After that kerosene, diesel, and then lubricant oil is synthesized.

8.    Is gasoline a pure substance?

From the components of gasoline structure, we can say that gasoline is not a pure substance, it is mixed of different kinds of hydrocarbons.

Gasoline is a mixture of n-alkanes like octane is the main substance but it is the composition of n-alkanes, branched alkanes, cycloalkanes, and some part of aromatics compound. So, there are different types of hydrocarbons are present in the gasoline structure, so gasoline is not a pure substance.

When is produced from crude oil, then the raw gasoline is not extracted because the crude oil goes through a different process, and in that process, there is a chance of adding different chemical compounds and catalysts. So, gasoline structure is always a mixed substance.

9.    Is gasoline polar?

The criteria of a molecule being polar are, that a molecule has some resultant dipole-moment, the electronegativity difference between two atoms is more than 0.4D, and the counter atoms have a tendency to polarize other atoms and other atoms should be polarizable.

We know gasoline structure is nothing but hydrocarbons, more specifically alkanes. In the alkane, there are only C and H atoms are present along with a single bond character. Single bond always sp3 hybridized, so the electronegativity of the nucleus is very poor. Again, the electronegativity of C and H is also low and almost equivalent. So, the electronegativity difference is almost zero for C and H atoms.

The gasoline structure is mainly octane. If we consider the structure of octane, we can see that the structure is symmetric in nature, so the dipole moment of octane acts opposite to each other and then cancel out the dipole-moment value. So, the net resultant dipole-moment value for gasoline structure is zero and thus making the molecule non-polar.

Generally, most of all hydrocarbons are non-polar unless there is present any electronegative atoms or functional group like -OH, then there is the possibility of making the molecule polar otherwise not. But here in gasoline structure, no such case is available so the gasoline structure is non-polar.

10. Is gasoline a renewable resource?

If the resource we can use again and again through the recycling process then is called a renewable resource, but if the resource we cannot use after one time then it is called a non-renewable resource. Any kind of fuel is an example of a non-renewable resource.

If we observe the gasoline structure, we can see there is a combination of C and H atoms making a hydrocarbon chain. When gasoline is used as fuel, then its combustion in the air, and during the combustion, C is transferred to carbon dioxide and the process of carbon dioxide to reverse back C is very difficult and it is done in the laboratory. That carbon dioxides are mixed in the open air and cannot get back into their form.

Actually, nonrenewable resources come from the earth’s crust. It is then extracted in solid, liquid, and gaseous form and then convert into suitable products which are related to energy substances e.g. nonrenewable resources including crude oil, natural gas, coal, and uranium. The fossil fuel is extracted into crude oil from the earth’s crust and converted into gasoline. These fossil fuel liquids are also refined for petrochemical products to produce plastics and polyurethane to respective solvents.

The main difference between renewable and non-renewable resources is, that non-renewable resources are limited and can be diminished over time but renewable energy is not.

11. Is gasoline a fossil fuel?

Yes, gasoline is one kind of fossil fuel. Some fossil fuels are refined into some derivates like kerosene and gasoline before burning them.

All the fossil fuels are non-renewable but all the non-renewable resources are not fossil fuels. e.g. crude oil, natural gas, and coal all are considered fossil fuels but uranium is not a fossil fuel uranium is found in the earth’s crust and its amount is also limited. Uranium is a radioactive metal so it cannot form in the same process as fossil fuels.

Crude oil or petroleum is the fossil fuel for gasoline. These fossil fuels can be formed by the sedimentation of rocks, when any organisms have died then they can turn into fossil fuels over billions of years, or the human body or any living being contained phosphate in their body after dying these phosphates turn into hydrocarbon like fossils. Fossil fuels are also hydrocarbons from which we can extract different crude oil or fuels.

12. Is gasoline a natural gas?

Natural gas is composed of methane and ethane whereas in gasoline structure the main skeleton is octane. Both gasoline and natural gas are extracted from the earth’s crust but the compositions are different and both are used as fuel. Both are fossil fuels but their nature and composition are different. So, gasoline is not natural gas.

13. Is gasoline blue?

The color of the gasoline structure is colorless or pale brown or sometimes pink, it depends on the composition of the hydrocarbons. We know gasoline is nothing but a hydrocarbon or alkane, an alkane, there is no such HOMO-LUMO gasp where the energy difference is high or low so the corresponding color will be visible. Mainly conjugated hydrocarbons show different colors due to electronic transaction

The color of kerosene is blue, because of the adding blue dye in it to identify the kerosene from petrol or diesel, but the low-quality kerosene is blue, and high-quality kerosene is white.

14. Is gasoline clear?

Gasoline is not dry, it is a liquid type of appearance so it is a clear substance. Sometimes gasoline will be dried for making different substances.

15. Is gasoline conductive?

The gasoline structure is made from hydrocarbon more specifically octane. Hydrocarbon is a bad conductor of electricity. Because they do not ionize and the mobility of their ions is very poor. So, gasoline is not a conductive agent, it can produce heat by burning itself because it is a good flammable agent.

16. is gasoline corrosive?

Gasoline is not corrosive to metals, even if it is not corrosive to human beings also. But inhaled gasoline vapor causes toxicity.

17. Is gasoline denser than water?

In the gasoline structure, we see there is an octane molecules present and the density of octane is much higher than water as it contains eight C atoms. So, gasoline is denser than water although both are liquids and due to different densities they are non-miserable.

18. Is gasoline elastic or inelastic?

Gasoline is a relatively inelastic product. From the density, it can be said that it is not elastic in nature.

19. Is gasoline heavier than air?

Gasoline structure is made from octane and the density of octane is much heavier than air, so gasoline is heavier than air.

20. Is gasoline heavier than diesel?

Diesel contains approximately 75% of aliphatic higher order hydrocarbons like C10H20–C15H28 and about 25% aromatic hydrocarbons with higher molecular weight like styrene, where gasoline structure is made from octane, so the diesel is heavier than gasoline.

21. Is gasoline hydrophobic?

Gasoline structure is the skeleton of hydrocarbons, and all the hydrocarbons are less affinity to water so, gasoline is hydrophobic in nature.

22. Is gasoline odorless?

There is benzene is also present in the gasoline structure, so it has a distinctive odor due to the presence of benzene as a component.

23. Is gasoline soluble in water?

Hydrocarbon is the main composition of gasoline structure, that’s why it is nonpolar and less soluble or insoluble in polar solvents like water. Also, it has a different density than water so it is insoluble in water and the hydrophobic part is also large.

24. Is gasoline volatile?

In the gasoline structure, there is a mixture of relatively volatile hydrocarbons like cycloalkanes, alkanes, and aromatics, so it is partially volatile in nature.

25. Is gasoline viscous?

Gasoline has a 0.006 centipoise viscosity value, so we can say that the gasoline structure is a lower viscous molecule.


Gasoline is a highly flammable substance and it catches fire easily. It is a non-renewable resource and non-renewable resources are the primary source of energy.

Biswarup Chandra Dey

Chemistry is not all about reading line by line and memorize, it is a concept to understand in easy way and here I am share with you the concept about chemistry which I learn because knowledge is worth to share it.

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