Chapter # 06 [Matter]

 

UNIT# 06

MATTER

Everything in this universe is matter and matter can be defined as the substance having mass and occupies space. Matter can be identify by their properties.

Q#	Questions	Year
Q# 01	Define Fusion.	[2017][2016][2010][2006]
Q# 02	Define Evaporation.	[2017][2016][2012] [2007] [2006]
Q# 03	Define Freezing point.	[2014]
Q# 04	Define Boiling point.	[2016][2014][2012] [2008] [2007][2006]
Q# 05	Define Diffusion.	[2016][2014][2013] [2012][2011][2010] [2008] [2007][2006]
Q# 06	Define Sublimation.	[2017][2016][2013] [2012][2010][2008] [2007][2006]
Q# 07	State Graham’s law of diffusion.	[2015][2010] [2009]
Q# 08	State Brownian motion.	[2016][2013][2012] [2008][2007][2006]
Q# 09	Write postulates of KMT.	[2011] [2009] [2008]

The kinetic energy is so named because it deals with the property of the particles which was so crucial in the understanding of the matter, namely the ‘motion of particles’, because particles are always in rapid motion as they possess kinetic energy which tends to keep them in a moving state.

 

Q. Define matter. Describe states of matter through Kinetic molecular theory.

MATTER

Anything that takes up space and has weight is called matter.

 

KINETIC MOLECUALR THEORY

1.      Matter is made up of small particles called atoms.

2.      Molecules are always in motion, indicate they possess kinetic energy.

3.      Movement of particles depends on temperature. It increases with increase in temperature and decreases with decrease in temperature.

4.      Movement of particles depends on pressure. It increases with increase in pressure and decrease with decrease in pressure.

 

STATES OF MATTER

Following are the three states of matter:

1.      Solid

2.      Liquid

3.      Gas

SOLID

A substance in which molecules are tightly packed having no spaces around them is called solid.

Solid possess definite shape and volume. It can never be compressed.

Solid may found in amorphous and crystalline form.

 

KINETIC MOLECULAR THEORY OF SOLIDS

1.      They have definite shape and volume.

2.      There are no intermolecular spaces between them.

3.      There are high intermolecular forces between the molecules.

4.      Solids are incompressible.

 

LIQUID

The substance in which intermolecular spaces are present but not more than the gases are termed as Liquids.

Liquid has not definite shape but it poses a definite volume.

 

KINETIC MOLECULAR THEORY OF LIQUIDS

1.      They have definite volume and indefinite shape.

2.      They have less intermolecular spaces.

3.      They have less intermolecular forces.

4.      Liquids are somewhat compressible.

 

GAS

Molecules having large spaces around them are termed as gases.

Gas has not any particular shape and volume as well.

 

KINETIC MOLECULAR THEORY OF GASES

1.      They have indefinite shape and volume.

2.      Gases have ability to diffuse

3.      They are compressible

4.      They have high intermolecular spaces and least intermolecular forces.

 

Q. State with example Brownian motion.

BROWNIAN MOVEMENT

STATEMENT

“A continuous, rapid and zigzag motion of suspended particles through the medium is called Brownian movement.”

 

FOR EXAMPLE

Mix some sulphur powder in water and stir it, after stirring filter the suspended sulphur some of the very small sulphur particles pass through the filter paper into the filtrate. Now put a drop of this filtrates on a slide and observe it, the sulphur particles will seem to perform random zigzag motion and this motion is called Brownian movement or motion.

 

Q. State with example Graham’s law of diffusion.

GRAHAM’S LAW OF DIFFUSION

STATEMENT

“Rate of diffusion of any gas is inversely proportional to the square root of its molar mass or density.”

EXPLANATION

Lighter gases can diffuse faster than heavier gases.

 

MATHEMATICAL EXPRESSION

r α

r = rate of diffusion

d = density of gas

 

FOR EXAMPLE

At similar conditions, the diffusion of hydrogen gas is four times faster than oxygen gas.

 

Q. State with example Henry’s law.

HENRY'S LAW

STATEMENT 

‘The weight of a gas is dissolved by any liquid is proportional to the pressure of the gas upon the liquid.”

The law, which was first formulated in 1803 by the English physician and chemist William Henry, holds only for dilute solutions and low gas pressures.

 

Q. Define Boiling point with examples.

BOILING POINT

The certain temperature the vapor pressure of liquid becomes equal to the atmospheric pressure is called boiling point.

FOR EXAMPLE

Boiling point of water is 100⁰ C

Boiling point of Carbon is 4027⁰ C

Boiling point of Nitrogen is -195.79⁰ C

 

Q. Define Sublimation with example.

SUBLIMATION

The process of conversion of solid directly into the gas is called sublimation.

FOR EXAMPLE

Camphor, iodine, dry ice etc

 

Q. Define Freezing point with examples.

FREEZING POINT

The temperature at which a liquid converts into a solid state when cooled is called freezing point.

FOR EXAMPLE

Freezing point of Water is 0⁰ C

Freezing point of benzene is 5⁰

Freezing point of Ethanol is -114.6⁰ C

 

Q. Define Evaporation with examples.

EVAPORATION

The escape of molecules from the surface of the liquid is called evaporation.

OR

The phenomenon of conversion of liquid into gas is called evaporation.

 

Q. Define Fusion with examples.

FUSION (MELTING)

The rise in temperature used in the change of state from solid to liquid is known as Fusion.

OR

The phenomenon of conversion of solid into liquid is called melting (Fusion).

 

Q. Define Melting point with examples.

MELTING POINT

Temperature at which solid converts into liquid is called melting point.

FOR EXAMPLE

The melting point of water is 0^o C

The melting point of Carbon is 3500^o C

The melting point of Nitrogen is -209.9^o C