Combustion Flashcards
why do alkanes make good fuels?
release a lot of energy when burned
Give the word equation for complete combustion
Alkane + Oxygen → Carbon Dioxide + Water
Give the word equations for incomplete combustion (2 possible)
Alkanes + Oxygen → Carbon Monoxide + Water (+ sometimes Carbon Dioxide)
Alkanes + Oxygen → Carbon + Water
Why is carbon monoxide gas poisonous? poisonous?
Binds to same sites on haemoglobin molecules in red blood cells as oxygen molecules ∴ oxygen cannot be carried around the body
what 2 dangerous gaseous products are produced by combustion in car engines?
carbon monoxide and nitrogen oxides
how are carbon monoxide and oxides of nitrogen removed from systems?
catalytic converters
how does a catalytic converter work?
a catalyst metal e.g. rhodium used to convert harmful products into more stable product like water and carbon dioxide.
How are oxides of nitrogen (NOx) produced?
Produced when high pressure and temperature in car engine causes nitrogen and oxygen atoms in air to react together
Where do unburnt hydrocarbons come from (carbon particulates) ?
Engines (they don’t burn all fuel molecules = come out as unburnt hydrocarbons)
what problems can unburnt hydrocarbons (carbon particulates) cause?
respiratory problems and can build up in engines meaning they dont work properly
what is the definition of a fuel?
substances that release heat energy when thy undergo combustion. also store a large amount of energy for a small amount of weight
why is incomplete combustion more likely to happen with longer chain hydrocarbons?
need more oxygen to burn
