Speed of chemical reaction depends on different factors, and, it is the most dependent on temperature. The rule works: the temperature is higher, the reaction proceeds quicker. This feature is actively used in various spheres: from power to medicine. At temperature increase the bigger quantity of molecules reach value of energy of activation of reaction, as leads to chemical interaction.
That chemical reaction took place, it is necessary that the interacting molecules had energy of activation. And, if each interaction of molecules led to chemical reaction, then they would occur continuously and proceeded instantly. In real life of molecular vibration lead to constant collisions between them, but not to chemical reaction. Energy is necessary for a rupture of a chemical bond between atoms, and, the communication is stronger, the more energy is required. Energy is necessary also for creation of new communications between atoms, and, the it is more difficult and more reliable new communications, the more energy is required.
Vant Hoff's rule
At temperature increase the kinetic energy of a molecule increases, so, probability increases that impacts will lead to chemical reaction. The first this regularity was revealed by Vant Hoff. Its rule says: at temperature increase on 10 ° the speed of elementary chemical reaction increases by 2-4 times. Respectively, also the return rule works: at fall of temperature the speed of chemical reaction slows down. This rule is correct only for small temperature intervals (ranging from 0 ° to 100 °C) and for simple connections. However the principle of dependence of speed of reaction on temperature remains substances, invariable for all types, in any environment. But at substantial increase or fall of temperature the speed of reaction stops being dependent, that is the temperature coefficient becomes equal to unit.
Arrhenius's equation
Arrhenius's equation is more exact and establishes dependence of speed of chemical reaction on temperature. It is used generally for complex substances and is correct even at rather high temperatures of the environment of course of chemical reaction. It is one of the main equations of chemical kinetics and considers not only temperature, but also features of molecules, their minimum kinetic energy of activation. Therefore, using it, it is possible to obtain more exact data for concrete substances.
Chemical rules in life
It is well known that to dissolve salt, sugar is much simpler in warm water, than in cold, and at considerable heating they are dissolved almost instantly. The damp clothes dry quicker in the warm room, products remain on cold better, etc.
It is necessary to remember that temperature one of the main, but not the only factor on which the speed of chemical reaction depends. It is influenced also pressure, by features of the environment in which it proceeds presence of the catalyst or inhibitor. The modern chemistry can control rather precisely the speed of chemical reaction, considering all these parameters.