d. Inside in a bomb calorimeter, 1.0 g of octane C8H18 combusts in
oxygen to form carbon dioxide and water according to the
expression 8 18 2 2 2 C H O CO H O + →+ 25 / 2 8 9 . The temperature was
observed to rise from 25.00 to 33.20 °C. The calorimeter
contained 1200 g of water (specific heat capacity of water =
4.184 Jg-1
K-1
) and the heat capacity of the bomb is 837 JK-1
.
Calculate the internal energy of combustion of octane.
2. Answer all parts.
(a) Briefly explain using specific examples and clearly labelled
diagrams how a Galvanic (Voltaic) cell and how a Polymer
Membrane Electrolyte (PEM) fuel cell operates.
(b) The net reaction that occurs in a voltaic cell is
2 Zn s Ag aq Zn aq Ag s () 2 ( ) ( ) 2 () + + + →+ . Write down the half
reactions that occur at the anode and cathode. If the standard