Question

A student observes the combustion (burning) of propane (C3H8). Because of the heat and light it generates, the student concludes that the reaction has NO activation energy. Is the student's conclusion correct, and why?

Answer 1

Answer:

The student's conclusion is not correct

Explanation:

Activation energy is the minimum amount of energy required for a reaction to occur. All reactions require there activation energy to be met before the reaction can proceed. When the temperature of a reaction is increased, the kinetic energy of the reactant molecules increases; colliding more with each other, which makes them "surmount" the activation energy of the reaction faster as compared to a lower temperature.

In combustion, there is burning of an hydrocarbon (in this case propane) in excess oxygen. The burning assists in increasing the kinetic energy of the reactant particles which in turn easily surmounts the activation energy of the reaction  by colliding (effective collision) more with oxygen. So, the reaction has an activation energy but the activation energy has been met and passed and hence the reaction is proceeding faster.

Increasing the temperature of a reaction is one of the ways of increasing the rate of a chemical reaction.