Exists a little most often used factors by means of which it is possible to change the speed of course of chemical reaction. Some of them allow to reduce time for dozens of percent, others – several times.
It is required to you
- The textbook in chemistry, the sheet of paper, a pencil.
Instruction
1. Glance in the school textbook in chemistry of the eighth or ninth class, having opened it on the paragraph about the speed of course of chemical reactions. To understand how it is possible to affect this speed, it is necessary to define for itself a concept of speed of this context. So, the speed of course of chemical reaction is determined by change of amount of the substance participating in it, or by change of a product of any reaction, calculated per unit of time and per unit of volume. This definition corresponds to homogeneous reaction. In case of heterogeneous reaction the calculation is performed on unit of an interface of phases.
2. Pay attention that the velocity of course of chemical reaction is as average, and instantaneous. Respectively, it is possible to influence both one, and other speed.
3. Notice also that the speed of chemical reaction depends by nature most reacting substance. The main factors influencing the speed of course of chemical reaction are temperature change, presence of catalysts and change of concentration of reagents.
4. Pay attention to the mechanism of impact of change of concentration of substances to the speed of course of chemical reaction. The essence of this effect is that the number of collisions of particles of the reacting substances directly depends on concentration of these particles. Increasing quantity of particles, it is possible to increase also the speed of chemical reaction. This dependence is reflected in the law of the operating masses.
5. Think of the mechanism of increase in speed of course of chemical reaction by means of increase in temperature. The fact is that this factor is the most often used along with use of catalysts. And it is possible to apply it to the majority of chemical reactions. The effect which had by this factor is calculated by Vant Hoff's rule. This law says that temperature increase increases the speed of course of chemical reaction by 10 wasps by three-four times.
6. Do not forget that all above-stated ways of change of speed of course of chemical reaction do not influence the nature and the mechanism of reaction and do not change the chemical composition of reagents, except a way on use of catalysts. Catalysts which are also often used for increase in speed though are not spent as a result of reaction course, but contain in structure of intermediate products of reaction. It is also known that catalysts reduce the total energy of activation of process that is connected with the fact that catalytic process goes on a special way, forming special intermediate particles.