Alkenes
Chapter Name : Hydrocarbons |
Sub Topic Code : 102_11_13_03_01 |
Topic Name : Alkenes |
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Sub Topic Name : Structure Of Double Bond |
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Introduction
In organic chemistry, an alkene is an unsaturated chemical compound containing at least one carbon–carbon double bond.
Pre-Requisites:
Alkenes
Activity:
Skeleton.
Real Life Question:
What are alkenes?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| double bond | A chemical bond between two chemical elements involving four bonding electrons instead of the usual two. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Azo compounds | Compounds bearing the functional group R-N=N-R', in which R and R' can be either aryl or alkyl. |
Real life uses :
Alkenes are used for artificial ripening of fruits, as a general anesthetic, for making poisonous mustard gas (War gas) and ethylene-oxygen flame.
Places to visit :
Chemistry laboratory.
Practical examples around us
| Examples | Explainations |
|---|---|
| Ethylene | A hydrocarbon with the formula C2H4 or H2C=CH2. It is a colorless flammable gas with a faint "sweet and musky" odor when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds), and the simplest unsaturated hydrocarbon after acetylene (C2H2). |
What you learn in Theory:
In molecules with alternating double bonds and single bonds, p-orbital overlap can exist over multiple atoms in a chain, giving rise to a conjugated system. Conjugation can be found in systems such as dienes and enones. In cyclic molecules, conjugation can lead to aromaticity. In cumulenes two double bonds are adjacent.
What you learn in Practice:
Double bonds are common for period 2 elements carbon, nitrogen, and oxygen, and less common with elements of higher periods. Metals, too, can engage in multiple bonding in a metal ligand multiple bonds.