CM8001

a) Exothermic: Heat is released during exothermic reactions
b) Endothermic: Heat is absorbed during reaction. Water absorbs heat from the surrounding and from our body temperature which translate into energy for the conversion of liquid to gaseous state.
c) Endothermic: Heat is absorbed during reaction. Ice absorbs heat from surroundings which results in the energy provided for solid to become to liquid.

A good explosion would be more exothermic. For exothermic reactions, the products have a lower energy level than the reactants, therefore bond strength of products is less than bond strength of reactants.

Heat is a form of energy transfer while temperature is the measurement of the amount of heat. Temperature is the direction of the flow of heat. For example, you feel hot because of the heat from the sun, and you can check the temperature with a thermometer.

a) 98% isooctane and 2% heptane
b) Octane rating does not indicate the level of oxygenates in fuel. Oxygenates are usually in gasoline to reduce carbon monoxide.