Alkanes Flashcards
How are alkanes similar to each other?
1) They have the same general formula.
2) Each member differs by CH2 and Mr of 14.
3) Same chemical property
4) Different physical property.
5) Can be prepared using similar methods.
What is the general formula of alkanes?
CnH2n+2
What is the amount of carbon atom in meth-?
1
What is the amount of carbon atom in eth-?
2
What is the amount of carbon atom in prop-?
3
Alkanes are saturated hydrocarbons. What does this mean?
It means they contain only single carbon-carbon covalent bond.
What are the properties of alkanes?
1) Unreactive
2) Low melting/boiling point
3) Insoluble in water
As we go down the group, what is the trend of alkanes?
The melting and boiling point and viscosity decreases.
What is complete combustion of alkanes?
When there is sufficient oxygen present. Alkanes burn to form carbon dioxide and water.
What in incomplete combustion of alkanes?
When there is insufficient oxygen present. Alkanes burn to form carbon monoxide, soot/carbon and water.
What are alkenes?
Alkenes are unsaturated hydrocarbons with the general formula of CnH2n. It means that it contains double carbon-carbon covalent bond.
What is cracking?
It is the breaking down of longchain hydrocarbons into smaller molecules.
What is the conditions of cracking?
A temperature of 600 degrees and aluminum oxide/silicion(IV) oxide.
What does alkenes do to bromine?
It decolourises bromine gas and bromine solution.
How is margarine made?
It is made by reacting unsaturated vegetable oils with hydrogen in the presence of a nickel catalyst at 200 degrees celsius.
