Rate Of A Chemical Reaction

For a reaction to be spontaneous only at high temperatures, the enthalpy change ( ) must be positive, indicating that the reaction absorbs heat. Additionally, the entropy change ( ) must also be positive, meaning the disorder of the system increases.
These factors influence the Gibbs free energy equation: As the temperature increases, the term , which is subtracted from , becomes significant enough to make negative, hence driving the reaction to spontaneity at higher temperatures.

For a first-order reaction, the integrated rate law is: where is the initial concentration, is the concentration at time , and is the rate constant.
The initial concentration of the reactant is 20 g, and it decreases to 2 g.
So: Solving for :

The total order of a reaction is the sum of the exponents in the rate law. In this case, the rate law is: The order with respect to is 1, and the order with respect to is .
Therefore, the total order is: