Which Alkane is the Isomer of Butane Called 2 Methylpropane

Which Alkane is the Isomer of Butane Called 2 Methylpropane.

Alkanes are the simplest hydrocarbons with all C-C bonds. Therefore, they are called saturated hydrocarbons. General formula for alkanes is CnH2n+2. All carbon atoms tend to consummate their tetra valency by bonding with the aforementioned or dissimilar atoms. In alkanes, all carbon atoms form single covalent bonds with other carbon atoms.

Table of Content

  • Isomers of Butane
  • Constitutional Isomers of Butane
  • Conformational Isomers of Butane

The parent chain can exist branched or unbranched and on the footing of that chemical and physical properties alter. Alkanes are less reactive compared to other hydrocarbons like alkenes, alkynes etc. This is considering, in alkanes, all carbon atoms are bonded with single covalent bonds which are strong and less reactive compared to double or triple covalent bonds of alkenes and alkynes respectively.

The members of the homologous series of alkanes are differed from each other by -CHii
unit of measurement. Every bit the number of carbon atoms increases in the series, the molecular mass also increases.

What are Isomers?

Isomers are molecules with the same molecular formula but different structural formulas. This miracle is called as isomerism.

Due to different structure, isomers may accept different chemical and physical properties too.

There are four carbon atoms in the given molecular formula. Then these four carbon atoms can arrange in two different manners. They tin either adjust in the directly chain of four carbon atoms or they can form a concatenation of 3 carbon atoms with one side chain.

Structural formula Name of isomer
CH3-CH2-CHtwo-CH3 n-butane
CHiii-CH(CHthree)CH3 2-methylpropane or isobutane

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What are the Isomers of Butane?

Isomerism in Organic Compounds

How Many Isomers Does Butane have?

Butane is an alkane with iv carbon atoms and so molecular formula is C4H10. Information technology has two isomers; due north-butane and isobutane.

Butane & Isobutane

Here n-butane is a straight-chain compound with four carbon atoms bonded with single covalent bonds.


Some other isomer is isobutane or 2-methylpropane in which three carbon atoms from the parent concatenation and one carbon atom is placed as the side chain at C-two of the parent chain. All carbon atoms take 4 valencies which are satisfied either by carbon atoms or hydrogen atoms.

Isobutane or 2 - Methylpropane

Constitutional Isomers of Butane

Constitutional isomers can be defined equally the compounds that have the same molecular formula but different structural formulas. In other words, constitutional isomers have different connectivity of atoms in molecules. To decide that two molecules are constitutional isomers of each other or not, we have to count the number of each atom in both molecules.

The molecular formula must be the aforementioned for both the molecules but the arrangement of atoms should be different. For example, wait at the construction of north-butane and isobutane.

Both of these molecules accept the same molecular formula that is C4H10. The connectivity of atoms (carbon atoms). In the case of n-butane, all carbon atoms are in straight-chain whereas, in the case of isobutane, at that place is a side concatenation in the molecule. So they take different connectivity of atoms and are constitutional isomers of each other.

Conformational Isomers of Butane

  • Stereoisomers which can exist converted into one another by rotation around a single bond are chosen conformational isomers.
  • Alkanes usually show conformational isomerism because of the presence of C-C bonds.
  • For case, when we rotate the molecule of butane at the axis of C-C bond, we get eclipsed, gauche, and anti butane conformational isomers.
  • Here eclipsed conformation has identical groups directly in-line with one another which makes it unstable.
  • Gauche conformation stands for the presence of identical groups at sixty degrees from one another.
  • Gauche is more stable compared to eclipse confirmation due to less steric hindrance between aforementioned molecules.
  • In anti conformation, identical groups are 180 degrees from 1 another which makes it the well-nigh stable form.
  • Each conformer is interconverted past rotating around the central carbon unmarried bail like eclipsed conformer can convert into gauche adapt by rotating sixty degrees.
  • Rotation of eclipsed by 180-degree forms anti- conformer. Rotation of anti butane past 120 degrees forms gauche conformer.

Staggered Conformation of Butane

  • The written report of conformers mainly involves the arrangement of atoms or groups with respect to primal cantlet.
  • There are different ways to represent conformers like Fisher project, Saw-equus caballus or Newman project.
  • Newman’southward projection can exist defined every bit the representation of a molecule in which the atoms and bonds are viewed forth the centrality of rotation.
  • In a Newman project, the forepart carbon is indicated as dot and dorsum carbon atom equally a circle. The substituent on carbon atoms can be viewed both in front of and behind the carbon-carbon bond.
  • For example in ethane molecule, in that location are ii possible conformations. One is with the dihedral angle 0° and another in which dihedral angle is 60 degrees.
  • The first example is called as eclipsed conformation in which the H atoms of C-1 line up with the H-atoms of C-2.
  • And then nosotros can say that in this conformation, the H-atoms are line upward perfectly close to each other.
  • In another conformer with dihedral lx degrees, the H-atoms of C-1 is far enough to H-atoms of C-ii. This is called the staggered conformation.

Staggered Conformation of Butane

Since H-atoms are far enough in staggered conformer, information technology is more than stable than eclipsed conformer. Staggered conformer of butane can exist in two forms; anti and gauche conformers. If we prepare the position of ane carbon atom of butane and rotate the other, it gives iii types of conformers, eclipsed, anti and gauche.

In that location are two kinds of staggered conformations.

  1. In

    , both methyl groups of butane are at anti position. Information technology is one of the nearly stable forms of butane.
  2. The other one is known equally

    gauche or skew conformation

Gauche or Skew Conformation

Frequently Asked Questions – FAQs

What is isomerism?

Isomerism in organic chemistry is a phenomenon shown by ii or more organic compounds having the same molecular formula just different properties due to differences in the arrangement of atoms along with the carbon skeleton (structural isomerism) or in infinite (Stereoisomerism)

What are the types of isomerism?

Two main forms of isomerism are structural or constitutional isomerism, in which bonds betwixt the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the aforementioned but the relative positions of the atoms differ.

What is Newman’s projection formula?

The conformation of a chemical bond from front end to back, with the forepart cantlet depicted as a dot and the back carbon as a circle, is visualized by a Newman projection, useful in alkane stereochemistry. The unique dihedral angle betwixt the proximal and distal atoms is conspicuously demonstrated past this grade of representation.

Ascertain conformational isomers?

Stereoisomers which tin be converted into one some other by rotation effectually a unmarried bond are called conformational isomers.

Why anti conformation is the most stable?

In anti conformation, identical groups are 180 degrees from i some other which makes it the most stable form.

Which Alkane is the Isomer of Butane Called 2 Methylpropane

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