Hydrocarbons Flashcards
What are hydrocarbons ?
A hydrocarbon is any compound that is formed from carbon and hydrogen atoms only.
What bonds do alkanes have ?
Alkanes have all c-c single bonds.
True or false : Alkanes are the most complex type of hydrocarbon you can get.
False - Alkanes are the simplest type of hydrocarbon you can get.
What is the general formula for an alkane ?
CnH2n+2
( the n’s and 2s are meant to be small )
The alkanes are a homologous series. What is a homologous series ?
A homologous series is a group of organic compounds that react in a similar way.
Alkanes are saturated compounds. What does this mean ?
Saturated compounds mean that each carbon atom of a alkane forms four single covalent bonds.
What are the first four alkanes ?
Methane- CH4
Ethane - C2H6
Propane- C3H8
Butane - C4H10
(The number are meant to be small )
What happens as the length of the carbon chain changes ?
The properties of the hydrocarbon change.
The shorter the carbon chain is, ……
The shorter the carbon chain is, the more runny a hydrocarbon is.
True or false: Hydrocarbons with shorter carbon chains have high boiling points.
False - Hydrocarbons with shorter carbone chains are also note volatile. I.e they have lower boiling points.
True or false : the shorter the carbon chain, the more flammable ( easier to ignite) the hydrocarbon is.
True
How do the properties of hydrocrabond affect how they’re used for fuels ?
E.g short chain hydrocarbon with lower boiling points are used as ‘bottles gases’ - stored under pressure as liquids in bottles.
When does complete combustion occur ?
Complete combustion occurs when there’s plenty of oxygen.
What is the equation for complete combustion of any hydrocarbon ?
hydrocarbon + oxygen - carbon dioxide + water ( + energy )
what are the only wast r products of complete combustion and what does any hydrogen in oxygen release lots of ?
Waste products: carbon dioxide and water vapour.
What does it release: lots of energy.
What is combustion an example of and how ?
Oxidation , During combustion both carbon and hydrogen are oxidised.
What is oxidation ?
Oxidation can be defined as the gain of oxygen.
Why are hydrocarbons used as fuels ?
They are used as fuels due to the amount of energy they release when they combust completely.
