MATTER IN OUR SURROUNDINGS…(here are some notes for matter in our surroundings that would help you in CBSE exam as well as competitive exams such as SSC)

 

Antoine-Laurent de Lavoisier is known as “the father of modern chemistry.”

  • MATTER
  • Matter is anything that occupies pace and has volume.
  • It is made up of small particles and these particles have inter molecular space and they would also posses motion.
  • On increasing temperature motion of particles also increases.
  • They have forces of attraction.

There are 5 states of matter in our surroundings:

  • STATES OF MATTER
  • Solid
  • Liquid
  • Gas
  • Plasma
  • Bose- Einstein Condensate

 

 

  • Matter in our surroundings: Solid state of matter
  • Definite shape and volume
  • Particles are closely packed
  • Greater forces of attraction therefore motion would be less.
  • Negligible compressiblity

matter in our surroundings: solid state of matter

 

  • Matter in our surroundings: Liquid state of matter
  • Definite volume
  • Indefinite shape and size
  • Inter molecular space between particles is comparitively more than solids but less than that of gases.
  • Forces of attraction is less as compared to solids hence motion is more.
  • Compressibilty greater than that of solids but less than that of gases.

matter in our surroundings : liquid

  • Matter in our surroundings: Gaseous state of matter
  • No definite shape,size and volume.
  • Inter molecular space is more.
  • Forces of attraction is very less hence greater motion
  • Compressibilty is also greater.

matter in our surroundings : gas bubbles

  • Plasma
  • Ionization of gases is called plasma.
  • When an electron is added or removed from the gas it becomes ionised and gains + or – charge .
  • Requires high temperature.
  • Easily affected by electric and magnetic field.
  • Eg: sun, fluorescent tube, neon lights

plasma: neon lights

  • Bose Einstein Condensate
  • Group of tom is cooled at absolute temperature i.e. 0 K or – 273.15 degree Celsius.
  • No free energy and no movement therefore behave like a single atom hence called Bose Einstein Condensate.

 

  • CHANGE IN PHYSICAL STATE OF MATTER
  • Solid to liquid———MELTING
  • Liquid to gas———-VAPORIZATION and EVAPORATION
  • Gas to plasma——-IONIZATION
  • Plasma to gas——DEIONISATION
  • gas to liquid———CONDENSATION and LIQUIFICATION
  • liquid to solid ——-FREEZING
  • Gas to solid———DEPOSITION
  • Solid to gas——-SUBLIMATION

 

  • LATENT HEAT OF VAPORIZATION
  • When 1kg of liquid is to be converted to gas, the amount of heat or energy required is called latent heat of vaporization.

 

  • LATENT HEAT OF FUSION
  • When 1kg of solid is to be converted to liquid, the amount of heat or energy required is called latent heat of fusion.

 

NOTE: temperature always remain constant and on increasing pressure particles come in motion and forces of attraction also increases.

 

Factors effecting evaporation are:

  • Humidity
  • Surface area
  • temperature

 

CHEMICAL CLASSIFICATION OF MATTER                                                   

 1. SUBSTANCE  : 

  • ELEMENTS (Metal, nonmetal ,metalloids)     
  • COMPOUND(  Organic. inorganic)                                               

2. MIXTURE

  • HOMOGENEOUS (Solution)
  • HETEROGENEOUS( Colloid, suspension)
  • SUBSTANCE 
  • It is a purest form of matter. This is a homogeneous material which consists of a single type of particles with definite set of properties.

ELEMENT : Simplest form of substance that cannot be broken down into more simpler substances. eg: oxygen,copper, hydrogen,etc. There are 118 elements known. the first 94 occurs on Earth and remaining are synthetic elements.

  1. METALS:  Metals comprise more than 78% of all known elements. Metals are lustrous, malleable, ductile, good conductors of heat and electricity. Other properties include: State: Metals are solids at room temperature with the exception of mercury, which is liquid at room temperature (Gallium is liquid on hot days).
  2. NON METALS: There are 22 non metals. Nonmetals have high ionization energies and electronegativities. They are generally poor conductors of heat and electricity. Solid nonmetals are generally brittle, with little or no metallic luster. Most nonmetals have the ability to gain electrons easily.
  3. METALLOIDS: They ave intermediate properties between metals and non metals.

COMPOUND: When two or more atoms of different elements are combined to form a molecule is called compound. eg: Water ,Sodium chloride. They have fixed composition. they can be broken down into elements.

matter in our surroundings

1.ORGANIC COMPOUNDS: Compounds formed by the carbon and hydrogen.

2. INORGANIC COMPOUNDS: Compounds formed by other elements other than carbon and hydrogen.

  • MIXTURE
  • A mixture is that form of matter in which two or more substances are simply mixed in any proportion.

A. HOMOGENEOUS MIXTURE: Components completely mix with each other and its composition is uniform through out. They are also called true solution( homogeneous mixture of solute and solvent wherein solute particles are very small such that not visible even with a powerful microscope. it’s about 1nm. Particles do not settle due to gravity)

TYPES OF SOLUTION 

  1. SOLID SOLUTION (solvent is solid and solute can be solid , liquid or gas)
  2. LIQUID SOLUTION(solvent is liquid and solute can be solid , liquid or gas) 
  3. GASEOUS SOLUTION(solvent is gas and solute is also gas)

Some definations:

1.Aqueous solution:Solutions that are made in water. eg: sugar solution.

2.Non aqueous solutionthe solutions that are made up of any solvent other than water. eg: sulphur in carbon disulphide.

3.Saturated solution: solution in which no more solute can be added at a particular temperature.

4.Unsaturated solutionsolution that contain less amount of solute than required to make saturated solution.

5.Supersaturated solution: solution that contain more amount of solute than saturated concentration.

B. HETEROGENEOUS MIXTURE: Mixtures which do not have uniform composition throughout are called Heterogeneous Mixture. For example – mixture of soil and sand, mixture of sulfur and iron fillings, mixture of oil and water etc.

  • COLLOID: 
  • appears to be homogeneous but is heterogeneous.
  • particles are visible with microscope.
  • size- 1 nm to 1000 nm
  • particles show Tyndall effect
  • do not settle down or take time to settle
  • eg: clouds, mud, milk,cream,blood
forms of colloidal solution solute(dispersed phase) solvent (dispersed medium) examples
foam gas liquid soap,foam,shaving cream,soda water
solid foam gas solid cake,bread
aerosol liquid/solid gas fog,cloud,smoke
emulsion liquid liquid milk,cream,butter
gel liquid solid curd,cheese,jelly
solid solution solid solid alloys,colored glasses

 

  •  SUSPENSION
  • it is  a heterogeneous mixture
  • solute particles are quite large
  • particles are visible even with naked eye.
  •  may or may not show Tyndall effect
  • particles may settle down due to gravity
  • eg: sand in water,mixture of chalk powder in water

TYNDALL EFFECT: The Tyndall effect is the scattering of light as a light beam passes through a colloid. The individual suspension particles scatter and reflect light, making the beam visible. As with Rayleigh scattering, blue light is scattered more strongly than red light by the Tyndall effect.

Tyndall effect

BROWNIAN MOTION: Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. It is the zig-zag motion of particles.

  • METHODS OF SEPARATION OF MIXTURE
  1. CRYSTALLIZATION: process by which chemical is converted from liquid solution into solid crystalline state. it is affected by physical conditions of a solution, temperature, impurities,etc.

matter in our surroundings : crystallization

  1. DISTILLATION: this process begins with heating a liquid to boiling point. The liquid evaporates forming a vapor. The vapor is then cooled usually passing through pipe or tubes at a lower temperature. Compounds having different boiling points can be separated usually using this method.

    Simple Distillation

    • Simple distillation involves heating the liquid mixture to the boiling point and immediately condensing the resulting vapors.
    • This method is only effective for mixtures wherein the boiling points of the liquids are considerably different (a minimum difference of 25oC).
    • The purity of the distillate (the purified liquid) is governed by Rouault’s law.

Fractional Distillation

  • Fractional distillation is often used to separate mixtures of liquids that have similar boiling points.
  • when the liquid is heated so it is converted into vapors that rise up in the fractional column. the vapor then cools and condensed on the walls of condenser.

Steam Distillation

  • It is often used to separate heat-sensitive components in a mixture.
  • This is done by passing steam through the mixture (which is slightly heated) to vaporize some of it. The process establishes a high heat-transfer rate without the need for high temperatures.
  • The resulting vapor is condensed to afford the required distillate.
  • The process of steam distillation is used to obtain essential oils and herbal distillates from several aromatic flowers/herbs

CHROMATOGRAPHY

  • this is a method  by which a mixture is separated by distributing its components between two phases.
  • stationary phase remains fixed while mobile phase carries the components of mixtures.
  • at different points in stationary phase the different components are absorbed.

EVAPORATION:

 Evaporation is the process by which water changes from a liquid to a gas or vapor. dissolved substance is left as solid and liquid evaporates. 

 

SEDIMENTATION:  Sedimentation is the process of allowing particles in suspension in water to settle out of the suspension under the effect of gravity. The particles that settle out from the suspension become sediment, and in water treatment is known as sludge

 

DECANTATION: Decantation is a process for the separation of mixtures of immiscible liquids or of a liquid and a solid mixture such as a suspension.

 

CENTRIFUGATION: 

  • it is the technique which involves the application of centrifugal force to separate particles from solution according to their shape,size,density,etc.
  • separated through spinning 
  • eg: milk cream,water from clothes.

complete notes of the chapter Matter in our surroundings …