Chemistry 7.1.3 Flashcards
Examples of Properties of Hydrocarbons that depend on the size of their Molecules: (3)
-Boiling Point.
-Viscosity.
-Flammability.
What influences how Hydrocarbons are used as Fuels?
Its Properties.
Each Alkane in a Homologous series has a BP ___ than the one before it.
Higher.
What Forces of attraction increase between the Molecules as Molecules get bigger?
Intermolecular Forces.
Why do Intermolecular Forces of attraction between Molecules increase as Molecules get bigger? (2)
-More Electrons in the Molecule.
-Greater Surface Area contact between them.
Because Intermolecular Forces increase as Molecule size increases, the ___ ___ of the Molecule also increases.
Boiling Point.
Define ‘Viscosity’:
The ease of flow of a Liquid.
High Viscosity Liquids are ___.
Thick.
Viscosity ___ when the Chain Length increases.
Increases.
Why do Viscosity increase when Chain Length increases?
Because of the stronger Intermolecular Forces of attraction between Molecules.
Why are longer chained Alkanes useful as lubricants in machinery?
Less likely to burn & reduce Friction between moving parts, due to their increased Viscosity. (Due to stronger IMF of attraction between Molecules).
What influences the Flammability of Hydrocarbons?
Its Molecular size.
Which are more Flammable: Smaller or larger Hydrocarbon Molecules?
Smaller.
Why are Smaller Hydrocarbon Molecules useful as Fuels?
Because they are more Flammable, and release lots of Energy when they burn.
Hydrocarbons undergo ___ in the presence of air.
Combustion.
