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This table provides a listing of alkyl groups and corresponding structures. Methyl is shown as C H subscript 3 followed by a dash. Ethyl is shown as C H subscript 3 C H subscript 2 followed by a dash. n dash propyl is shown as C H subscript 3 C H subscript 2 C H subscript 2 followed by a dash. Isopropyl is shown as C H subscript 3 C H C H subscript 3 with a dash extending upward from the middle C. n dash butyl is shown as C H subscript 3 C H subscript 2 C H subscript 2 C H subscript 2 followed by a dash. sec dash butyl is shown as C H subscript 3 C H subscript 2 C H C H subscript 3 with a dash extending upward from the third C counting left to right. Isobutyl is shown as C H subscript 3 C H C H subscript 2 with a dash extending to the right. There is a C H subscript 3 bonded to the middle C. tert dash butyl is shown as C H subscript 3 C C H subscript 3 with a C H subscript 3 group bonded below the middle C and a dash extending upward from the central C.
This listing gives the names and formulas for various alkyl groups formed by the removal of hydrogen atoms from different locations.

Note that alkyl groups do not exist as stable independent entities. They are always a part of some larger molecule. The location of an alkyl group on a hydrocarbon chain is indicated in the same way as any other substituent:

This figure shows structures of 3 dash ethylheptane, 2 comma 2 comma 4 dash trimethylpentane, and 4 dash isopropylheptane. The 3 dash ethylheptane structure shows C H subscript 3 C H subscript 2 C H subscript 2 C H subscript 2 C H C H subscript 2 C H subscript 3. Under the C atom labeled 3, is a bond to C H subscript 2 C H subscript 3 which appears in red. The C atoms are labeled 7, 6, 5, 4, 3, 2, and 1 from left to right. The 2 comma 2 comma 4 dash trimethylpentane structure shows C H subscript 3 C bonded to C H subscript 2 C H C H subscript 3. The C atoms are labeled 1, 2, 3, 4, and 5 from left to right. The C atom labeled 2 has a C H subscript 3 bonded above it and below it. The C H subscript 3 groups both appear in red. The C atom labeled 4 has a bond above it to C H subscript 3. The C H subscript 3 group appears in red. The 4 dash isopropylheptane structure shows C H subscript 3 C H subscript 2 C H subscript 2 C H C H subscript 2 C H subscript 2 C H subscript 3. From the fourth C counting from left to right, there is a C H group bonded above. Bonded up and to the right and and up to the left of this C H group are C H subscript 3 groups.

Alkanes are relatively stable molecules, but heat or light will activate reactions that involve the breaking of C–H or C–C single bonds. Combustion is one such reaction:

CH 4 ( g ) + 2 O 2 ( g ) CO 2 ( g ) + 2 H 2 O ( g )

Alkanes burn in the presence of oxygen, a highly exothermic oxidation-reduction reaction that produces carbon dioxide and water. As a consequence, alkanes are excellent fuels. For example, methane, CH 4 , is the principal component of natural gas. Butane, C 4 H 10 , used in camping stoves and lighters is an alkane. Gasoline is a liquid mixture of continuous- and branched-chain alkanes, each containing from five to nine carbon atoms, plus various additives to improve its performance as a fuel. Kerosene, diesel oil, and fuel oil are primarily mixtures of alkanes with higher molecular masses. The main source of these liquid alkane fuels is crude oil, a complex mixture that is separated by fractional distillation. Fractional distillation takes advantage of differences in the boiling points of the components of the mixture (see [link] ). You may recall that boiling point is a function of intermolecular interactions, which was discussed in the chapter on solutions and colloids.

This figure contains a photo of a refinery, showing large columnar structures. A diagram of a fractional distillation column is also shown. Near the bottom of the column, an arrow pointing into the column from the left shows a point of entry for heated crude oil. The column contains several layers at which different components are removed. At the very bottom, residue materials are removed through a pipe as indicated by an arrow out of the column. At each successive level, different materials are removed through pipes proceeding from the bottom to the top of the column. In order from bottom to top, these materials are fuel oil, followed by diesel oil, kerosene, naptha, gasoline, and refinery gas at the very top. To the right of the column diagram, a double sided arrow is shown that is blue at the top and gradually changes color to red moving downward. The blue top of the arrow is labeled, “Small molecules: low boiling point, very volatile, flows easily, ignites easily.” The red bottom of the arrow is labeled, “Large molecules: high boiling point, not very volatile, does not flow easily, does not ignite easily.”
In a column for the fractional distillation of crude oil, oil heated to about 425 °C in the furnace vaporizes when it enters the base of the tower. The vapors rise through bubble caps in a series of trays in the tower. As the vapors gradually cool, fractions of higher, then of lower, boiling points condense to liquids and are drawn off. (credit left: modification of work by Luigi Chiesa)

In a substitution reaction    , another typical reaction of alkanes, one or more of the alkane’s hydrogen atoms is replaced with a different atom or group of atoms. No carbon-carbon bonds are broken in these reactions, and the hybridization of the carbon atoms does not change. For example, the reaction between ethane and molecular chlorine depicted here is a substitution reaction:

This diagram illustrates the reaction of ethane and C l subscript 2 to form chloroethane. In this reaction, the structural formula of ethane is shown with two C atoms bonded together and three H atoms bonded to each C atom. The H atom on the far right is red. Ethane is added to C l bonded to C l, followed by an arrow that points right. The arrow is labeled, “Heat or light.” To the right, the chloroethane molecule is shown with two C atoms bonded together. The left C atom has three H atoms bonded to it, but the right C atom has two H atoms bonded above and below it along with a C l atom. The C l atom appears in red with 3 pairs of electron dots at the right end of the molecule. This is followed by a plus sign, which in turn is followed in red by H bonded to C l. Three pairs of electron dots are present above, to the right, and below the C l.

The C–Cl portion of the chloroethane molecule is an example of a functional group    , the part or moiety of a molecule that imparts a specific chemical reactivity. The types of functional groups present in an organic molecule are major determinants of its chemical properties and are used as a means of classifying organic compounds as detailed in the remaining sections of this chapter.

Alkenes

Organic compounds that contain one or more double or triple bonds between carbon atoms are described as unsaturated. You have likely heard of unsaturated fats. These are complex organic molecules with long chains of carbon atoms, which contain at least one double bond between carbon atoms. Unsaturated hydrocarbon molecules that contain one or more double bonds are called alkenes . Carbon atoms linked by a double bond are bound together by two bonds, one σ bond and one π bond. Double and triple bonds give rise to a different geometry around the carbon atom that participates in them, leading to important differences in molecular shape and properties. The differing geometries are responsible for the different properties of unsaturated versus saturated fats.

Questions & Answers

mention some examples of ester
Chinenye Reply
do you mean ether?
Megan
what do converging lines on a mass Spectra represent
Rozzi Reply
would I do to help me know this topic ?
Bulus
oi
Amargo
what the physic?
Bassidi Reply
who is albert heistein?
Bassidi
similarities between elements in the same group and period
legend Reply
what is the ratio of hydrogen to oxulygen in carbohydrates
Nadeen Reply
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Nadeen
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Nadeen
what is poh and ph
Amarachi Reply
please what is the chemical configuration of sodium
Sharon
2.8.1
david
1s²2s²2p⁶3s¹
Haile
2, 6, 2, 1
Salman
1s2, 2s2, 2px2, 2py2, 2pz2, 3s1
Justice
1s2,2s2,2py2,2
Maryify
1s2,2s2,2p6,
Francis
1s2,2s2,2px2,2py2,2pz2,3s1
Nnyila
what is criteria purity
Austin Reply
cathode is a negative ion why is it that u said is negative
Michael Reply
cathode is a negative electrode while cation is a positive ion. cation move towards cathode plate.
king
CH3COOH +NaOH ,complete the equation
david Reply
compare and contrast the electrical conductivity of HCl and CH3cooH
Sa Reply
The must be in dissolved in water (aqueous). Electrical conductivity is measured in Siemens (s). HCl (aq) has higher conductivity, as it fully ionises (small portion of CH3COOH (aq) ionises) when dissolved in water. Thus, more free ions to carry charge.
Abdelkarim
HCl being an strong acid will fully ionize in water thus producing more mobile ions for electrical conduction than the carboxylic acid
Valentine
differiante between a weak and a strong acid
david
how can I tell when an acid is weak or Strong
Amarachi
an aqueous solution of copper sulphate was electrolysed between graphite electrodes. state what was observed at the cathode
Bakanya Reply
write the equation for the reaction that took place at the anode
Bakanya
what is enthalpy of combustion
Bakanya
Enthalpy change of combustion: It is the enthalpy change when 1 mole of substance is combusted with excess oxygen under standard conditions. Elements are in their standard states. Conditions: pressure = 1 atm Temperature =25°C
Abdelkarim
Observation at Cathode: Cu metal deposit (pink/red solid).
Abdelkarim
Equation at Anode: (SO4)^2- + 4H^+ + 2e^- __> SO2 + 2H2O
Abdelkarim
Equation : CuSO4 -> Cu^2+ + SO4^2- equation at katode: 2Cu^2+ + 4e -> 2Cu equation at anode: 2H2O -> 4H+ + O2 +4e at the anode which reacts is water because SO4 ^ 2- cannot be electrolyzed in the anode
Niken
what is the electrolysis of sulphuric acid
Bakanya Reply
why is electrolysis difficult using solid lead chloride
Bakanya
what is heat formation
Biefon Reply
what are atoms
Happy Reply
this are small substances that form together and complained one
Belvine
okay gud
Bol
what's covalent bonding
Basil Reply
Covalent bonds are characterized by the sharing of electrons between two or more atoms. These bonds mostly occur between nonmetals or between two of the same (or similar) elements.
Haile
covalent bonding is the mutual sharing of electrons between two element in a molecule, usually it involves non metals as they are less ionic and more electronegative than metals( ionic). and these bonds have high enthalpy of formation. and are strong bonds than most of the bond.
Chiranjeev
covalent bonding involves both nonmetals where there is complete sharing of electrons on the outermost energy level
david
I don't understand
Belvine

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Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
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