Chemistry

posted by .

Consider a fuel cell that uses the reaction of ethanol with oxygen to produce electricity,
CH3CH20H(l)+ 3O2(g)---> 2CO2(g)+3H2O

Use thermodynamic data to determine the value of E°cell for this cell at 25 °C.

I don't really know where to start. I got the standard G for
CH3CH2OH: -174.8 kJ/mol
O2: 0 kJ/mol
CO2: -394.4 kJ/mol
H2O: -237.1

I was thinking maybe I should use deltaG = deltaG(products)- deltaG(reactants).

Then use the equation of of deltaG = -nFEcell and manipulate it to Ecell=deltaG/-nF, but then I don't know how many n is transferred.
Can someone please help me with the problem? I don't really understand how to do it.

  • Chemistry -

    Yes you do exactly what you have outlined. I would look at change in C and change in O for n. If we see ethanol as C2H6O and assign oxiatioin states of -2 for O and +6 for 6H, that makes 2 C in ethanol as -4. On the right the 2C are +8 so the change in e is 12. We can check that number with O to make sure we're right. We have 1O in ethanol which we called -2 and it is -2 in CO2 and H2O so it hasn't changed at all. That leaves us with 6 O on the left at zero going to 6 O on the right at -2 each or 6*2 = 12 so O has changed by 12 e. That checks. n must be 12

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    Suppose a hydrogen-oxygen fuel-cell generator was used to produce electricity for a house. Use the balanced redox reactions and the standard cell potential to predict the volume of hydrogen gas (at STP) required each month to generate …
  2. chemistry

    Suppose a fuel-cell generator was used to produce electricity for a house. If each H2 molecule produces 2e- , how many kilograms of hydrogen would be required to generate the electricity needed for a typical house?
  3. chem

    Suppose a hydrogen-oxygen fuel-cell generator was used to produce electricity for a house. Use the balanced redox reactions and the standard cell potential to predict the volume of hydrogen gas (at STP) required each month to generate …
  4. chemistry

    A certain voltaic cell has a standard cell voltage of 1.22 V, and 3 electrons are transferred in the overall cell reaction. What is the value of the thermodynamic equilibrium constant for this cell reaction at 298K?
  5. Chemistry

    Suppose a fuel-cell generator was used to produce electricity for a house. If each H2 molecule produces 2e-, how many kilograms of hydrogen would be required to generate the electricity needed for a typical house?
  6. Chemistry

    Suppose a fuel-cell generator was used to produce electricity for a house. If each H2 molecule produces 2e- how many kilograms of hydrogen would be required to generate the electricity needed for a typical house?
  7. AP Chemistry

    A voltaic cell is constructed that uses the following half-cell reactions. Cu+(aq) + e- Cu(s) I2(s) + 2 e- 2 I -(aq) The cell is operated at 298 K with [Cu+ ] = 2.3 M and [I - ] = 3.3 M. (a) Determine E for the cell at these concentrations. …
  8. Chemistry - Science

    A fuel cell designed to react grain alcohol with oxygen has the following net reaction: C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l) The maximum work that 1 mol of alcohol can yield by this process is 1320 kJ. What is the theoretical …
  9. chemistry

    A voltaic cell can be built using the reaction between Al metal and O2 from the air. If the Al anode of this cell consists of 65 g of aluminum, how many hours can the cell produce 1.5 A of electricity, assuming an unlimited supply …
  10. Biology :)

    Consider the following situation. A cell is in a solution that contains dissolved oxygen. As the cell uses oxygen for respiration, a. oxygen will be carried across the cell membrane by special transport molecules. b. oxygen will naturally …

More Similar Questions