Chemical Fuel Cells/ Bond Energies

Question 1

Explain the difference between endothermic
and exothermic reactions by discussing the
making and breaking of bonds. 6 marker

Answer 1

An exothermic reaction is when energy is transferred into the surroundings.
An endothermic reaction is when energy is taken into the surroundings.
energy is needed for bond breaking
energy is released from bond making
In exothermic reactions, more energy being released in the bond making of products than what is taken breaking the bonds in reactants.

In endothermic reactions, less energy is being released in the bond making of products than what is taken breaking the bonds in reactants.

Question 2

Evaluate and describe the pros and cons of the fuel cells-

Answer 2

Alkaline cell-
cheaper to manufacture
May end up in landfill sites and expensive to be recycled

Rechargeable cell-
Able to be recharged many times before being recycled
Costs more to manufacture

Hydrogen oxygen fuel cell-
Easy to maintain because there are no moving parts, small in size.

Very expensive to manufacture because it needs a constant supply of hydrogen fuel which is a flammable gas