Study Online and Download KIPS 9th Class Chemistry Notes Unit 5: Physical States of Matter.
Study Online and Download KIPS 9th Class Chemistry Notes Unit 5: Physical States of Matter. Matter exists in three physical states i.e. gas, liquid and solid. The simplest form of matter is the gaseous state. Liquids are less common and most of the matter exists as solid. Matter in gaseous state does not have definite shape and volume. Therefore, gases occupy all the available space. Their intermolecular forces are very weak. Pressure is a significant property of gases. The effect of pressure and temperature on volume of a gas has been studied quite extensively.
The liquid state has strong intermolecular forces hence it has definite volume but it does not have definite shape. It attains the shape of the container in which it is kept. Liquids evaporate and their vapours exert pressure. When vapour pressure of a liquid becomes equal to external pressure, it boils. Liquids are less mobile than gases therefore, they diffuse slowly.
The solid state has definite volume and shape. They are rigid and denser than liquids and gases. They exist in amorphous or crystalline forms.
Students will be able to:
- Effect on the volume of a gas by a change in the a. pressure b. temperature.
- Compare the physical states of matter with regard to intermolecular forces present between them.
- Account for pressure-volume changes in a gas using Boyle's Law.
- Account for temperature-volume changes in a gas using Charles' Law.
- Explain the properties of gases(diffusion, effusion and pressure).
- Explain the properties of liquids like evaporation, vapour pressure, boiling point.
- Explain the effect of temperature and external pressure on vapour pressure and boiling point.
- Describe the physical properties of solids (melting and boiling points).
- Differentiate between amorphous and crystalline solids. Explain the allotropic forms of solids.
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