The rate of reaction `((dx)/(dt))` varies with nature, physical state and concentration of reactants, temperature, exposure to light and catalyst, whereas rate constant `(K)` varies with temperature and catalyst only. The rate constant `K` is given as `K=Ae^(-E_(a)//RT)` where `A` is Arrhenius parameter or pre-exponential factor and `E_(a)` is energy of activation. The minimum energy required for a reaction is called threshold energy and the additional energy required by reactant molecules to attain threshold energy level is called energy of activation.
The temperature coefficient of reaction `I` is `2` and reaction `II` is `3`. Both have same speed at `25^(@)C` and show `I` order kinetics. The rati of rates of reaction of these two at `75^(@)C` is: