Reactions Of Alkanes Flashcards
(13 cards)
Why are short chained hydrocarbons valuable?
They can be used as clean fuels - often used in the home for cooking and heating
Why are alkanes relatively unreactive?
Because the C-C and C-H bonds are very strong and have low polarities. However alkanes can still be involved in some reactions
What is equation for complete combustion
Alkane + oxygen = carbon dioxide + water
This is highly exothermic.They are good fuels because they release large amounts off if energy per gram of fuel
Name the pollutants and the problems they cause
- Carbon monoxide (CO) - is a toxic gas for humans
- Nitrous oxides and sulphur oxides - may react with oxygen in the air to form nitric and sulphuric acids which are
components of acid rain. - Carbon particulates - trigger asthma and may cause cancer
- Unburnt hydrocarbons - contributes to photochemical smog
- Carbon dioxide - causes climate change in high concentrations
- Water vapour - A greenhouse gas
How do power stations reduce the pollutant sulphur dioxide?
Calcium carbonate can be sprayed on the flue gas to remove the sulphurous oxides.
Reacting lime (CaO) produces what useful building material?
Gypsum
What reduces nitrous oxide and carbon dioxide emissions in cars
Catalytic converters
Why does a catalytic converter have a honeycomb structure?
To give it a larger surface area
What is the catalytic converter made from?
Platinum and rhodium
What do the rhodium and platinum act as
They act as catalysts for the harmful gases to react with each other
What is the equation for the harmful gases reacting with each other
2CO(g) + 2NO(g) -> N2(g) + 2CO2(g)
What are the conditions for the formation of nitrous oxides
Nitrogen reacting with oxygen in the air at the high temperatures of combustion
State a reason for sulphur dioxide being found in exhaust gases
Petrol/ fuels contain sulphur
