Alkanes Flashcards
What is the different between complete and incomplete combustion?
Complete combustion is when there is enough oxygen, incomplete is when there isn’t which may result in the production of carbon monoxide
Give a hazard of incomplete combustion
Production of carbon monoxide means when breathed in, it attaches to haemoglobin and takes other place of oxygen causing internal suffication
Which process is used to separate alkanes of different boiling points?
Fractional distillation
Why do cycloalkanes have higher boiling points?
They contain more van der waals so more kinetic energy is required to break these bonds
When burning alkanes, what is the general formula in complete combustion?
Alkane + oxygen –> carbon dioxide + water
What are alkanes?
Main components of natural gas and crude oil. They are very unreactive and are mainly used In fuels to generate heat when reacted with oxygen
Give the general formula of alkanes
CnH2n+2
Give the properties of alkanes
Saturated hydrocarbons
Contain covalent bonds
Contain a sigma bond
What is a covalent bond?
A shared pair of electrons
What is a sigma bond?
A bond in which each carbon atom is joined to 4 other atoms
It is the result of two overlapping orbitals, one from each bonded atom
What is the effect of chain length on boiling point?
The greater the chain length the higher the boiling point because more surface contact results in more VdW’s so more energy is required to break them
What is the effect of branching on boiling point?
More branching results in a lower boiling point as there is less surface contact so there are less VdW’s forces and thus less energy is required
Give a problem with complete combustion?
CO2 contributes to greenhouse effect and thus global warming
Why is a hydrocarbon non-polar?
The electronegativity difference between C and H is so similar that it can be considered non-polar
What is a pi bond?
A pi bond is the covalent bonding over two neighbouring p orbital’s unpaired electrons to create an electron pair
