According to the collision theory of reaction rates, an increase of the temperature at which the reaction occurs will inturn increase the rate of the reaction. This is caused due to: (a) Greater number of molecules are having the activation energy (threshold energy) (b) Greater velocity of reaction molecules (c) Greater number of collisions (d) None of these

When considering why chemical reactions occur at different rates, the concept of activation energy is central. It's the minimum quantity of energy required for reactants to transform into products during a chemical reaction. Imagine it as a hurdle that reacting particles must overcome to result in a chemical transformation. This 'energy barrier' ensures that molecules don't change into new substances without the necessary input of energy. When molecules collide with energy less than the activation energy, they simply bounce off each other, remaining unchanged. If they possess energy equal to or greater than activation energy - voila! - they have a chance to react and form new products.

In every group of molecules, only a fraction has enough energy at any given time to overcome this barrier. The collision theory of reaction rates intertwines with activation energy, as it postulates that the rate of a reaction corresponds to the frequency of collisions between molecules, combined with the proportion of these collisions that have enough energy to get over the activation energy hurdle.

Diving into the realm of chemical kinetics, we explore the speed and factors influencing the course of chemical reactions. Chemical kinetics deals with the rates of chemical processes and the mechanisms by which they occur. It is a vast subject that encompasses aspects like reaction rates, the pathways molecules take during a reaction, and how different conditions affect the speed of a reaction.

Several factors influence kinetic rates, including the concentration of reactants, the presence of a catalyst, the physical state of the reactants, and temperature. Understanding chemical kinetics is vital for fields ranging from medicine, where the rate at which a drug acts could be crucial, to environmental science, where reaction rates can affect pollution dynamics. It's about figuring out the 'how fast' and 'why' behind chemical changes.

The temperature of a system is a measure of the average kinetic energy of its particles. When the temperature rises, molecules move with greater velocity, colliding more often and with more energy. According to the collision theory, not only does the number of collisions per second increase with temperature, but the proportion of collisions that have enough energy to overcome the activation energy barrier also increases.

Think of it like a busy kitchen: with more heat, the molecular chefs move quicker and with more urgency, resulting in more dishes (or reactions) completed. The chance of a successful 'meal' goes up because these chef molecules are more likely to have the energy needed to 'cook' something new. To further aid understanding, take into account that for many reactions, a 10-degree Celsius increase in temperature can roughly double the rate of the reaction, revealing the significant effect temperature can have on how swiftly a reaction proceeds.