Question

List an example of a fast chemical change, a chemical change accompanied by a change in color, and a chemical change accompanied by release of heat.

Answer 1

Chemical change is a change which is accompanied by the formation of new substances due to the occurrence of the certain chemical reaction.

Part I - Example of fast chemical change

• Magnesium ribbon burns in the flame of a Bunsen burner and produces a dazzling spark and this process takes place in ${10}^{-6}sec$

Part II - Example of chemical change accompanied by change in color

• Rusting is an example of chemical change accompanied by change in color as the exposition of iron to moist air leads to the formation of a brown powdered mass which is known as rust.

Part III - Example of a chemical change accompanied by release of heat

• Combustion is a process of chemical change where a substance burns in the presence of oxygen and there is a liberation of heat and light.