- a) Exothermic reaction as it is a combustion reaction and it releases heat energy.
b) Endothermic reaction. The body loses heat which is gained by the water, thus allowing it to change from liquid to gaseous state.
c) Endothermic reaction. The ice absorbs heat energy from the surroundings.
2. In an exothermic reaction, a large negative net energy change, bonds formed for the products release more energy compared to the energy absorbed during bond breaking between the atoms of the reactants. Since the products are more stable, the bond strength is higher for the products compared to that of the reactants.
3. Heat is a form of energy. On the other hand, temperature is a measurement that indicates the direction heat will flow. Heat always flows from an object at higher temperature to an object at lower temperature. For example, if ice is added into hot water, the heat energy will flow from the hot water to the ice. As a result, the final temperature of the mixture equilibrate between the original temperatures of the ice and hot water.
4. (a) The knocking characteristics of this gasoline is 98% isooctane and 2% heptane.
(b) Since this gasoline consists of isooctane and heptane, the fuel is not oxygenated.
