CM8001

a. Exothermic – A burning process is releasing heat
b. Endothermic – Water absorbs heat to become water vapour. The H-bonds are also broken in the process
c. Endothermic – Solid ice absorb heat to become liquid.

The bond energy of the reactants are relatively weak and the bond energy of the products are very strong. Thus, more energy is released when the chemical reaction takes place. This will lead to a a negative net energy change, which indicates a large exothermic reaction during an explosion.

Temperature is the property of internal energy : it is the state of the matter(current state).
Heat is the amount of energy transferred between two matters.

For example, if we put ice cubes into a cup of hot coffee, the temperature of the hot coffee will drop and that is due to the heat transfer from the coffee to the ice.

a. Since the premium gasoline has an octane rating of 98, it will burn relatively smoothly. It also indicates that it shows 98% burning properties of iso-octane and 2% of heptane.

b.It has a high possibility to contain oxygenates because normally premium gasoline have a very low octane rating. But it does not give any concrete information/evidence whether there is oxygenates.