Why does increasing concentration or pressure increase reaction rate?
Increasing concentration - When you increase the concentration of reactants in a solution this means there are more particles of the reactants in the same volume of solution, so it is more 'crowded'. This makes it more likely that they will collide. So the more frequent collisions will lead to a faster reaction time.
Increasing pressure - When you increase the pressure the gas particles are squashed together so that there are more of them in a given space. This means there will be more frequent collisions which will lead to a faster reaction time.
The rate of a reaction is affected by the concentration of reactants in solutions and by the pressure if the reactants are…