This is a very vague question and would depend on the chemical that you are talking about. The easiest way I can think to explain it on a wide variety of chemicals is by using a catalyst (speeds up the process of a chemical reaction), or the use of an antagonist (Slows a chemical reaction). I hope this helps, but without any specific chemicals being named this is the best i can do. :)
By heating we can change the rate of chemical change(reaction).
This is called reaction rate.
The average rate of disappearance for a substance in a chemical reaction is the speed at which the substance is used up over time. It is calculated by dividing the change in concentration of the substance by the change in time.
A catalyst.
chemical
The chemical properties of an object show what a chemical change did to that substance.
The process is spelled catalysis (change in reaction rate).The substance that makes a chemical reaction change is a catalyst.
chemical change is the change of one substance into another substance.
Catalyst is a a substance that raises the rate of a chemical reaction without necessarily experiencing any any permanent chemical change.
chemical change
A chemical change is a change in the composition or structure of a substance, resulting in the formation of new substances with different properties. This type of change is usually irreversible and involves the breaking and forming of chemical bonds.
burning the substance.
The substance formed in a chemical change is called Product.