Alkanes Flashcards
What chemical property of alkanes links to oxygen?
alkanes undergo complete combustion when they react completely with oxygen
alkanes are flammable
Describe the structure of alkanes
single bonds only
What is the formula of alkanes?
CⁿH²ⁿ⁺²
What are alkanes?
a homologous series of hydrocarbons
What is a homologous series?
-a series of compounds:
in which molecular formula of neighbouring members differ by CH₂
that show a gradual variation in physical properties, such as boiling points
that have similar chemical properties
that have the same general formula
What is produced when alkanes react completely with oxygen?
carbon dioxide and water vapour
What do the names of the alkanes always end in?
‘ane’
e.g. ethane, propane
What is the difference in the strength of intermolecular forces depending on the size of the molecules?
intermolecular forces are stronger between bigger molecules
they are weaker between smaller ones
State four features of a homologous series
- same general formula
- molecular formula of neighbouring members differ by CH₂
- gradual variation in physical properties
- similar chemical properties
The molecular formula for icosane is C₂₀H₄₂. Predict the molecular formula for heneicosane, the next member of the alkane homologous series.
C₂₁H₄₄
What does the molecular formula differ by between members?
CH₂
