Posted on by Cae Ryn

AE 3 (8 Feb ’17)

  1. a)Exothermic. A charcoal briquette releases heat as it burns.
    b) Endothermic. Water absorbs the heat necessary for evaporation from your skin, and your skin feels cooler.
    c)Endothermic. Ice absorbs the necessary heat from the environment to melt.
  2. The bond strengths of the products should be stronger than the bond strengths of the reactants. If the bond strengths of the products are higher, it would release a lot of energy, making the reaction very exothermic and hence a good explosion
  3. 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. This means that if hot water is added to cold water, heat will flow from the hot liquid to the cold liquid, and the final temperature of the mixture will be between the original temperatures of the two individual solutions. Heat depends on the temperature and on how much material is present.
  4. a. Gasoline with an octane rating of 92 has the same knocking characteristics as a mixture composed of 92% isooctane and 8% 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.