[Chemistry Class Notes] on Physical Properties Pdf for Exam

Anything that occupies space and has some mass is called matter. And every matter in this universe consists of physical and chemical properties which change when it undergoes reaction. These  properties of matter are either chemical or physical and  further, these physical properties are either extensive or intensive. It is important to study the properties of substances to understand their nature. Every substance reacts differently as all of them consist of different physical properties. There are different ways to observe the physical and chemical properties of the substances. For example, non metals have different ways of reacting towards acid from metals as the properties of metals and non-metals differ.

Properties of Substances

These properties are either intensive or extensive or they can be classified as physical or chemical. The examples of extensive properties are volume or mass depending on the amount of the measured matter. The examples of intensive properties are color or density which do not depend on the amount of matter. It is important to note that physical properties are both intensive or extensive properties. These can be estimated without controlling the chemical identity of the substances. The example of physical property can be explained with the help of  freezing water, when we freeze the water, it will still remain water , however, only the physical state will change. The other examples of physical properties can be measured or demonstrated by studying color, density, volume and mass of the substances. It only changes the physical state of the substance but doesn’t change the chemical composition of the substances. Some changes also include more than one type of change in their properties. For example, if we blend two fruits to make a juice. This change will include two types of physical changes as it will change the state of matter from solid to liquid and mixing of pieces of fruits. However, there is no chemical change involved here. Some of the other physical change includes: 

Physical and Chemical Properties

As we discussed, the physical properties are the properties which are either intensive or extensive. The intensive properties are not seen with the naked eyes while the extensive ones are easily observed. The intensive ones are color, density while the extensive properties are the volume , mass etc. The reaction involving any change in these extensive or intensive properties is called physical properties. These changes did not result in any change of the chemical composition unlike the chemical change. For example, the physical properties of soil changes include the texture, porosity, density etc. It gets affected in case of soil erosion. 

Similarly, the physical properties of  acid which are most likely to change when it undergoes any reaction are its sour taste, the change in its color (litmus paper). 

The chemical properties are referred to as that property which lead to the change in the chemical structure. The examples of chemical properties are the heat of combustion which is the energy released when a compound undergoes complete combustion (burning) with oxygen,  or Chemical stability which is determined if a compound will react with water or air as the stable chemical substance will not react. The chemical changes are the changes which lead to change in the chemical composition example, cooking, rusting etc. as they produce new chemical compounds.

Physical Properties of Non Metal

There is a significant difference between metal or non-metals. The appearance of metals and non metals differs due to their different physical properties. The intensive or extensive physical properties of the nonmetal determine its appearance and its reaction with other substances. These physical properties can be of great utility in some cases. For example, copper is used to make electrical wires as they are conductors and will allow the electricity to pass. However, you cannot use non-metal in this case as it will not allow the electricity to pass. The physical properties of non-metal also decides its utility like high-ionization energies, poor conductor of heat, low density, etc. 

Conclusion 

The physical properties can determine its application. The physical properties are extensive or intensive. The extensive ones volume, mass etc and the intensive ones are the density, etc. The change which leads to the change in the physical property without affecting the chemical property is called Physical change. The change which results in the change of the chemical composition or it leads to the formation of a new chemical compound is called chemical change.