CM8001

a) Exothermic because it releases heat as it burns.
b)Endothermic. Because Particles gain energy as they go from a liquid to a gas.
c)Endothermic. Melting process needs heat to proceed and takes it from the warm water.

The bond energies of the products are larger than those of the reactants. This will lead to a negative net energy change indicating a large exothermic reaction.

Heat is a form of energy. In contrast, temperature is a measurement
that indicates the direction heat will flow. Heat always flows from an object at high
temperature to an object at lower temperature. A drop of ot coffee is of the same temperature but you will get a bigger burn from the cup of coffee because of the higher heat content.

a)Gasoline with an octane rating of 98 has the same knocking characteristics as a mixture composed of 98% isooctane and 2% heptane. In essence, this is a blend that is resistant to knocking.
b)The octane rating does not give you any additional information about whether or not the fuel contains oxygenates. Other labels around the pump should reveal this information.