Key Tests to Identify Aliphatic Compounds in Chemistry
Vedantu has explained an aliphatic compound that contains hydrogen and carbon joined collectively in the straight chains. These chains are non-aromatic and branched trains in the rings. These compounds find their usage in corrosion inhibitors.
The aliphatic compounds are the hydrocarbons compounds of alkyne, alkane, an alkene in the form of fatty acids, and different other related compounds. The compounds that own rings are known as aromatic compounds. So, aliphatic compounds are just the opposite of aromatic compounds.
If we talk about the industrial applications of alicyclic and aliphatic, these may include chemical intermediates, solvents, metal-cleaning agents, and fire-extinguisher compounds. Aliphatic compounds are also famous as non-aromatic and aliphatic hydrocarbons.
Aliphatic compounds are usually found in rubber, dyes, dry cleaning, plastics, varnish, paints, chemicals, pharmaceuticals, textiles, and more. Specific aliphatic compounds are also found in resins and paraffin products. These are also used as fumigants, intermediates, and insecticides. These compounds are used in two different ways such as unsaturated and saturated. Saturated compounds always remain joined by single bonds while unsaturated compounds are joined by triple and double bonds.
This is a simple overview of the aliphatic compound provided by the Vedantu experts. This gist has been provided in order to make the students familiar with the concept. Once they are able to gain familiarity, they can learn a good definition and proceed with other sections. Then, they go to the structure part and learn how the aliphatic compound is structured. After this, they are able to learn tests based on this compound.
Don't worry regarding the language ease as Vedantu takes care of it and uses only comprehensive language so that students are able to go on the learning journey with a smiling face. So, let’s start with aliphatic compound chapter in detail:
What is Aliphatic Hydrocarbon?
Aliphatic Hydrocarbon Meaning - Aliphatic usually implies an aliphatic compound, meaning an organic compound in which the atoms are bound by single, double, or triple bonds to form nonaromatic structures. The alkenes, alkynes, and alkanes, as well as the substances extracted from them - directly or in theory - by replacing one or more hydrogen atoms with atoms from other groups of atoms or elements, make up the main structural groups of organic molecules known as aliphatic compounds. In this way, we can give the aliphatic compounds meaning.
Structure- Aliphatic compounds can be either saturated (alkanes) or unsaturated (alkenes) with single or double bonds (alkenes) or triple bonds (alkenes) (alkynes). Other elements, in addition to hydrogen, can be bound to the carbon chain, the most common of which are oxygen, nitrogen, sulphur, and chlorine. Whereas, aliphatic carbon (hydrocarbon) is an organic chemical.
The least complex of all aliphatic compounds is methane \[CH_{4}\].
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Tests to Identify Aromatic and Aliphatic Compounds
Ultraviolet radiation is blocked by aromatic compounds. The majority of aliphatic compounds do not absorb UV radiation, but those with three or more conjugated double bonds do.
Assuming that the aromatic ring contains an H atom, which is attached to it, we can find the resonance of proton NMR around 7 ppm. Aliphatic compounds will not have a peak in that specific area.
Also, there are some differences in the IR spectrum as well.
The elemental analysis will also give a clue, as:
A benzene ring = 4 unsaturation degrees = eight “missing” hydrogen atoms, which are relative to a saturated compound.
However, there are some other ways to get 4 degrees of unsaturation (for example, two triple bonds).
This is a crucial section from a scoring point of view and once you are versed with the testing method, then your whole answer will be correct. Associated with practical sessions, Vedantu assists students to follow all the steps so that they are guided at each step or not to be left with any step. This is just like a mathematical equation that has to be resolved and attempted accurately. Remember either you will get full marks or no marks for a wrong attempt. Therefore, stay careful and keep your preparation strong enough to stay confident as well as stay correct.
Difference between Aromatic and Aliphatic Compounds
Let us look at the difference between aromatic and aliphatic hydrocarbons meaning with various parameters as tabulated below.
The difference between aliphatic and aromatic compounds is also crucial just like the test steps. The reason behind it is that you can get a detailed question regarding the difference or you can get some short notes to write. Suppose you have short notes on both the terms then you can just expect to earn maximum marks as correct short notes are always considered scoring rather than a lengthy question. Plus, you should not forget to keep examples of both of these handy in your mind as examples always lead to impress the examiner. Stick to Vedantu’s study material and see the difference in your preparation.
Steps to Determine the More Reactive Compound
The chemical reactivity of the substance is based upon its thermodynamic stability. All the chemical reactions involve existing bonds breaking and making new ones, mostly by the release of excess energy in the heat form. It is also said that the greater the thermodynamic stability of the substance, the lower will be the tendency of it to undergo a chemical change.
An important thermodynamic parameter to define the stability is its standard enthalpy of formation. Let us discuss comparing the standard enthalpy of formation (in kJ/mol) of the hydrogen halides:
HCl -92.3
HF -273.3
HI +26.5
HBr -36.3
The more negative the formation enthalpy, the greater will be the stability of the compound formed. Also, the lower will be its tendency to react in a given specific environment.
The regular reactive nature of the hydrogen halides will be increased in the order HF < HCl < HBr < HI, and their respective thermodynamic stability will be decreased in the order HF > HCl > HBr > HI.
Most Reactive Metal
Lithium is given as the most reactive metal. But, it is a generalization simply because we have to specify the one it is going to react with. There are several reactive metals such as Sodium, Lithium, Aluminum, Cesium, Potassium, Calcium, Magnesium, and others. The ones such as Aluminum might appear quite nonreactive at first, but if it is finely powdered and the surface oxide coating is removed, then it will be as in the reactive mode.
If we think about the energy released in a Thermite reaction, it is enough to melt and weld together two large volumes of railway tracks, or the solid rocket boosters, which are used to boost the vehicles into orbit, or in the military flash-bang, there is plenty of power in Aluminum. Again, the soft metals such as potassium and sodium literally explode if thrown into the water or any other similar liquid, and a piece, which is the size of a tennis ball, is thrown into a lake; it gives us one hell of a scare.
Then, let us discuss what do we mean by reactive? What about the two pieces of Plutonium 239 or Uranium 235? Bring together two pieces of a certain weight, and we will no longer be around. Those particular smaller pieces are emitting trillions and trillions of the fast-moving Neutrons, which are why those pieces are a little warm in our hands, and if we have enough of the stuff at one place, then those particular neutrons contain a nasty habit of building up more and more neutrons by the process of colliding with the atoms, releasing even MORE of them, in a cumulative runaway process of cascading, a chain reaction, which spreads in less than a microsecond, bombarding those atoms, so, they split into the smaller parts, and releases energy in that process.
So, that is the other form of reactivity, but not the chemical reactivity, which is simply the atom’s electrons, but nuclear reactivity, which is the protons, neutrons, and nucleus. This is where the huge majority of all the energy of matter is found. So we can see that it entirely depends on what we mean by saying reactive and in what way the reactive is? And with what reaction? and more.
Conclusion
How was the matter shared by the Vedantu tutors? This is superbly simple and easy to grasp and you must have got complete guidance from the teaching staff of Vedantu to keep your preparation strong for the real examination. Now, you have the best material with you, it is up to you how you are going to follow the best study routine. Either you can go along stepwise with Vedantu or you can also map out your own plan according to your flexibility. Ensure that you learn and revise regularly without a miss.
FAQs on Aliphatic Compounds: Meaning, Structure & Importance
1. What is an aliphatic compound in simple terms?
An aliphatic compound is an organic compound where carbon atoms are linked in straight chains, branched chains, or non-aromatic rings. Think of them as the basic building blocks of organic chemistry without the special ring structure of aromatic compounds. They can be saturated (with single bonds, like alkanes) or unsaturated (with double or triple bonds, like alkenes and alkynes).
2. What are some common examples of aliphatic compounds?
Some of the most common aliphatic compounds include:
- Methane (CH₄): The simplest alkane, a major component of natural gas.
- Ethane (C₂H₆): Used in the chemical industry.
- Propene (C₃H₆): An alkene used to make polypropylene plastic.
- Acetylene (C₂H₂): An alkyne used in welding torches.
3. What are the key properties of aliphatic compounds?
The main property of most aliphatic compounds is that they are highly flammable, which is why many are used as fuels (like methane, propane, and butane). Their boiling and melting points generally increase with the size of the carbon chain. Shorter-chain compounds are typically gases at room temperature, while longer ones are liquids or waxy solids.
4. How do aliphatic, alicyclic, and aromatic compounds differ?
These terms describe the structural arrangement of carbon atoms:
- Aliphatic: Refers to open-chain compounds (straight or branched).
- Alicyclic: These are aliphatic compounds that form a non-aromatic ring. Cyclohexane is a classic example. They behave chemically like their open-chain counterparts.
- Aromatic: These are compounds containing at least one special, highly stable ring of atoms, like a benzene ring, that follows specific bonding rules (e.g., Hückel's rule).
5. Why are alkanes often called aliphatic compounds?
The term 'aliphatic' comes from the Greek word aleiphar, which means 'fat' or 'oil'. Early chemists discovered that heating or breaking down animal fats and oils produced open-chain compounds like alkanes. Because these compounds were first derived from fats, the name 'aliphatic' was given to them and now covers the entire class of open-chain and alicyclic hydrocarbons.
6. How does the structure of an aliphatic compound affect its properties like boiling point?
The structure has a direct impact on properties. For instance, a straight-chain aliphatic compound like pentane has a higher boiling point than its branched-chain isomer, neopentane. This is because the straight-chain molecules can pack together more closely, leading to stronger intermolecular forces (van der Waals forces) that require more energy to overcome.
7. What is the difference between saturated and unsaturated aliphatic compounds?
The difference is in the type of carbon-carbon bonds they contain. A saturated aliphatic compound, like an alkane, has only single bonds between its carbon atoms. An unsaturated aliphatic compound, like an alkene or alkyne, has at least one double or triple bond between carbon atoms, making it more chemically reactive.
8. Where can we find examples of aliphatic compounds in our daily lives?
Aliphatic compounds are all around us. The LPG (Liquefied Petroleum Gas) used for cooking is a mix of propane and butane. The petrol and diesel that fuel vehicles are complex mixtures of aliphatic hydrocarbons. Plastics like polyethylene (used for bags and bottles) and PVC are made from aliphatic monomers.
