• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12

To calculate the energy per mole of substance

Extracts from this document...


The Tables To calculate the energy per mole of substance, simply divide the number of moles which you calculated were burned into 1. because you only burned a fraction of a mole of each alcohol in each test, the answer you get when you divide 1 by the number of moles tells you how many times you must multiply the energy result in you table by, to get the energy per 1mole of substance. For this reason you should use s formulae of this form: 1 . number of moles of substance burned * energy value in table = energy per mole of substance. So energy per mole = energy value from table(1/number of moles burned) The structural formula: The letter corresponds to the element it represents from the periodic table. The single line which links it to another letter signifies a single bond between it and the other element. The structural formula: C3H7OH The letter represents it's corresponding element from the periodic table, the subscripted number on the lower right side of the letter signifies how many of those similar elements there are in the compound. ...read more.


1 2 3 mean average total mass of burner before burning (g) 102.45 102.55 106.35 103.78 total mass of burner after burning (g) 102.20 102.30 106.10 103.53 mass of alcohol burned (g) 0.25 0.25 0.25 0.25 mass of water (kg) 0.1400 0.1405 0.1395 0.1400 starting temperature (deg. Centigrade) 17.00 17.00 17.00 17.00 final temperature (deg. Centigrade) 28.00 28.00 28.00 28.00 change in temperature (deg. Centigrade) 11.00 11.00 11.00 11.00 RMM 60.00 60.00 60.00 60.00 moles of substance burned =Mass/RMM 0.0042 0.0042 0.0042 0.0042 energy=mc 6.47 6.49 6.44 6.47 energy per mole = energy value from table(1/number of moles burned) =6.47(1/0.0042) =1540.4762kj/mole so an alcohol with a chain length three carbons long will release 1540.4762kj/mole when burnt. Structural formula: Molecular formula: C3H7OH Total number of bonds between elements:10 Combustion of propanol: C3H7OH + 4.5O2 --> 4H2O + 3CO2 Butanol (C4H9OH) 1 2 3 mean average total mass of burner before burning (g) 83.90 89.40 77.40 83.57 total mass of burner after burning (g) 83.60 89.10 77.10 83.27 mass of alcohol burned (g) 0.30 0.30 0.30 0.30 mass of water (kg) ...read more.


From this table it is possible to conclude that as the number of carbons in the alcohol increases, so does the energy of the reaction. This is because during any reaction bonds are broken, so all the atoms are left unattached to each other, then in the end of the reaction the atoms re-attach, forming a different compound than that which was present in the beginning. In any reaction, energy is required to break bonds, and energy is released bonds are made. The amount of energy required or released depends upon the types of bonds being made or broken. In an exothermic reaction, there is more energy released from the formation of the bonds than was required to break the bonds. This extra energy is released as thermal (heat) energy. In an endothermic reaction, heat is "Taken in" from the surroundings, because less energy is released when the bonds were made than was required to break the bonds, the extra energy required is taken from the environment around the reactants. The amount of energy required may be displayed in a chart called a reaction profile. This tracks the energy change through the course of the reaction. The energy profiles for the five alcohols are displayed: Methanol: Ethanol: Propanol: Butanol: Pentanol: Reaction profiles: ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Energy, Respiration & the Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Energy, Respiration & the Environment essays

  1. Marked by a teacher

    To make sure we have plenty of energy in the future, it's up to ...

    4 star(s)

    One of you might be another Albert Einstein and find a new source of energy. It's up to all of us. The future is ours but we need energy to get there. Related web sites: Generating New Ideas for Meeting Future Energy Needs Fossil Fuels and the Environment * Although

  2. the effect of bile concentration on the activity of the enzyme lipase during the ...

    will be affecting enzyme activity Always start the experiment at the same pH by adding the carbonate ions until the pH probe reads the same reading as previously By starting the experiment at different pH's each time we do an experiment we will be affecting the enzymes activity as pH

  1. Discuss the Advantages and Disadvantages of being Ectothermic and Endothermic in the Vertebrates.

    they are able to quickly store up energy in their bodies during their brief periods of activity (the high tolerance level of their tissues contributes to this: e.g. they are able to ingest more salts than endotherms). This low cost lifestyle means that Ectotherms can also be much smaller than

  2. To investigate how much energy (Kj) is stored in different types of peanuts and ...

    Thermometer: to measure the temperature. 8) Water 9) Stand and an adjustable clamp: to hold the test tube above the base for safely. 10) Bunsen burner: to heat the peanuts and pea. 11) Heat proof mat: for safety. 12)

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work