1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Amount of moles emitted by burning oil

  1. Apr 3, 2014 #1
    1. The problem statement, all variables and given/known data

    Calculate the number of moles of CO2 that are emitted into the atmosphere per year due to the total energy consumption on earth (16TW). Note: 1kg oil yields 42MJ and for oil C:H ' 1:2.

    I don't know how to calculate how many grams/moles of CO2 are emitted by burning 1kg of the oil

    2. Relevant equations

    3. The attempt at a solution

    - 1 mole CO2 is 44g

    - I calculated that 1,22x10^13 kg oil is needed to cover the 16TW
  2. jcsd
  3. Apr 3, 2014 #2
    The problem approximates the formula for oil as a chain of CH2s. Each CH2 reacts with O2 to produce H2O and CO2. Can you write a balanced reaction equation for the reaction of each CH2 group with O2?
  4. Apr 3, 2014 #3


    User Avatar

    Staff: Mentor

    Or, from a slightly different (but yielding the same answer) angle: if the experimental formula is CH2, how many grams of C and how many grams of H in 1 kg of the substance?
  5. Apr 3, 2014 #4
    Thank you so much for your input!

    Let's check if I understand it better now:

    2CH2+ 3O2 gives 2H2O + 2CO2

    So 2 mol oil gives 2 mol CO2

    1 mol oil weights 14g
    1 mol CO2 weights 44g
    1.22 x 1013 kg oil/ 14 x 10-3 = 871x106mol oil
    Which equals the amount of moles CO2

    Is this correct?
  6. Apr 3, 2014 #5


    User Avatar

    Staff: Mentor

    Chemistry looks OK to me, but on the second read I am not sure how to understand

    16TW is not energy consumption, it is power required. I see you assumed it is intended to mean "average power required throughout the year" - looks OK to me, still, question could be worded better.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted