• Question: how to hydrocarbon chains effect combustion?

    Asked by ThatGammaGamer to David, Gemma, Juhi, Matt, Stéphane, Yinka on 9 Mar 2018.
    • Photo: Matt Bawn

      Matt Bawn answered on 9 Mar 2018:

      In general:

      Hydrocarbons with small molecules make better fuels than hydrocarbons with large molecules. This is because small hydrocarbon molecules:

      are more volatile – turn into a gas more easily
      are less viscous – they flow more easily
      are more easily ignited
      burn with a cleaner, less sooty flame

      http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/oneearth/fuelsrev3.shtml

    • Photo: Gemma Chandratillake

      Gemma Chandratillake answered on 10 Mar 2018:

      Ha! Haven’t done this stuff since Chemistry at school! It’s all flooding back to me, burning various hydrocarbons and seeing how sooty the flame is on mineral paper! Felt I should look this up rather than rattle off what I remember – hope this helps!
      “Since different hydrocarbons have different ratios of hydrogen to carbon, they therefore produce different ratios of water to carbon dioxide. In general, the longer and more complex the molecule, the greater the ratio of carbon to hydrogen. For this reason, combustion of equal amounts of different hydrocarbons will yield different quantities of carbon dioxide, depending on the ratio of carbon to hydrogen in molecules of each. Since coal contains the longest and most complex hydrocarbon molecules, burning coal releases more CO2 than burning the same mass of oil or natural gas.”
      http://energyeducation.ca/encyclopedia/Hydrocarbon_combustion

    • Photo: Stéphane Berneau

      Stéphane Berneau answered on 11 Mar 2018:

      A hydrocarbon reacts with oxygen to create carbon dioxide, water, and heat. They are most famous for being the primary constituent of fossil fuels, natural gas, petroleum, and coal.

      Depending on the amount used for combustion, the need in oxygen will also increase leading to an excessive amount of carbon dioxide emission.

      I have added a little video which explains how these fossil fuels were generated:

Comments