a. Exothermic, as charcoal briquette releases heat as it burns.
b. Endothermic, as the water absorbs the heat necessary for evaporation.
c. Endothermic, as heat is absorbed from the environment to break the bonds of ice.

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

Temperature is a form of measurement to indicate how heat flows while heat is a form of energy. Heat flows from a hotter object to a cooler object. Hence, an example would be, pouring hot water to a cup of cold water. The heat from the hot water will flow to the cold water and the final temperature will be a mixture between the two solutions.

a. Gasoline with an octane rating is composed of 98% isooctane and 2% n-heptane. As it is a ‘premium gasoline’, it has a high resistance to knocking.
b. Octane rating does not contain any information pertaining to the fuel containing oxygenates or not. Other labels around the pump will contain this information.