4 Alkanes Flashcards
What are alkanes?
They are the simplest family of hydrocarbons.
What are many of the alkanes used for?
Fuels.
How do you draw methane?
How do you draw ethane?
How do you draw propane?
How do you draw butane?
What is an isomer?
They are compounds that have the same molecular formula but different structural formulas.
What is the general formula for alkanes?
CnH2n+2
Why are alkanes saturated hydrocarbons?
Because the hydrocarbon only has single bonds, and each carbon atom is bonded to as many hydrogen atoms as possible. There are no double bonds.
What are the steps you take to name organic compounds?
- Find the longest c chain.
- Start numbering from the side closest to the functional group or branch.
- Start the name with the number of C atoms in the chain and then give the ending according to the homologous series. If there is a double bond, indicate its position with a number before the ending.
what does di-methyl mean?
There are two more branches, containing the formula CH3.
What is the formula for methyl?
CH3.
What is the formula for ethyl?
CH3CH2 (C2H5).
What do the little numbers show before the formula?
Where the branches are in terms of the carbon branch.
When do alkanes react with halogens? (for susbstitution)
In the presence of ultraviolet radiation.
What happens in term of structure during substitution?
A hydrogen atom in the alkane is replaced by a halogen atom.
What is the word equation used to describe what happens in substitution involving methane and bromine?
Methane + Bromine -> Bromomethane + Hydrogen bromide
What happens during that reaction of substitution?
A mixture of methane and bromine gas is orange because of the presence of bromine. If it is exposed to sunlight, it loses its colour, and a mixture of bromomethane and hydrogen bromide gases is formed.
What is the formula to describe what happens in substitution involving methane and bromine?
CH4 + Br2 –> CH3Br + HBr
What is mono-substitution?
It occurs when only one hydrogen atom in the alkanes is replaced by a halogen atom
What are the products formed from substitution reactions called?
Halogenoalkanes.
How are the halogenoalkanes named?
According to the format x-halogenoalkane, where x is the position of the halogen atom in the longest carbon atom chain.
What is an example of x-halogenoalkane being used?
1-bromopropane or 2-bromopropane.
