1.

a) Exothermic. Requires energy to start the combustion.

b) Endothermic. Heat from the skin transfers to water on the skin. Heat is converted into kinetic energy i.e. gas molecules are moving.

c) Endothermic. Heat is added causing the molecules to move, increasing kinetic energy.

2.  For the reactants the bond strength would be weaker because less energy is required to break the bond. For the products the bond strength would be stronger resulted in more energy being released.

3. Heat is the flow of energy from hotter to colder objects. Temperature determines direction of heat flow. To give an example, the number of people in a room. Each one of us gives off heat transferring to the molecules in a room. The heat causes the molecules’ average speed to increase. Hence the rising temperature; the more people in a room, the higher the temperature.

4.

a) It has a knocking characteristics of 98% isooctane & 2% n-heptane.

b) No, we are not able to tell if it contains oxygenates.