Increasing temperatures in a reaction increases the kinetic energy of the reactant molecules. This causes them to move fast and hence collide with a higher frequency. The higher the rate of collision between the molecules, the faster the reaction.
The given formula for heat, Q=mc(Tf-Ti), is the best way to solve such problems with changes in temperature. It can be said that m is the mass of the substance. C is the specific heat of the substance. The term (Tf-Ti) is the change in temperature.
