Study Materials

NCERT Solutions for Class 9th Science

 

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Chapter 2. Is Matter around us Pure

Additional -Questions 2

 

 

 

Additional-Questions:

Que- Write the difference between mixture and compound?

                                  Mixture                          Compound

(i)  Element or compound just mix together to from a mixture and no new compound is formed.

(ii)  A mixture has a variable composition.

(iii)  A mixture shows the properties of the constituents substances.

(iv)  The constituents can be separated farily easily by physical methods.   

(i)  Element react to from new compounds.

(ii)  The composition of each new substance is always fixed.

(iii)  The new substance has totally different propreties.

(iv)  The constituents can be separated only by chemical or electrochemical rections.     

Que: Write the various methods of separation.

Ans:

  1. Evaporation
  2. Chromatography.
  3. Centrifugation.
  4. Sublimation.
  5. Filtration.
  6. Crystallisation.
  7. Distillation.
  8. Magnetic separation.
  9. Separating Funnel.
  10. Winnowing
  11. Decantation.
  12. Sedimentation.   

Que- What type of mixtures are separated by the technique of crystallisation?

Ans:(i) Salt from sea water.

        (ii)  Alum (Phitkari) from impure sample.

Que: -Which separation techniques will you apply for the separation of the following?

 

a. Sodium chloride from its solution in water.

Ans: Evaporation .

b. Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.

Ans: Sublimation.

c. Small pieces of metal in the engine oil of a car.

Ans: Filtration.

d. Different pigments from an extract of flower petals.

Ans: Chromatography.

e. Butter from curd.

Ans: Centrifugation.

f. Oil from water.

Ans: Separation funnel. 

g. Tea leaves from tea.

Ans: Filtration.

h. Iron pins from sand.

Ans: Magnetic Separation.

i.  Wheat grains from husk.

Ans: Winnowing.

j. Fine mud particles suspended in water.

Ans: Decantation.

  

 Que; - Differentiate between homogeneous and heterogeneous mixtures with examples.?

Ans: - Homogeneous - Mixture having uniform composition are called homogeneous mixture. Ex. Mixture of sat in water and mixture of alcohol in water.

Heterogeneous – those mixture that do not have uniform composition are called heterogeneous mixture.ex. mixture of salt and sugar ,Mixture of sand and salt. 

 

Que: - how can we separate a mixture two immiscle liquid?

Ans:- By Separating Funnel.

Que:- What is distillation ?

Ans:- 

 

Que-1 What is a Mixture?

Ans-Mixture consist of more than one kind of pure form of matter,know as a substance of mixture.

Que-2 What type of matters around us?

Ans-There are two types of matter around us:(i)PURE SUBSTANCE (ii)IMPURE SUBSTANCE.

Que-3 What is pure substance?

Ans-Thoes substance which contains particles of only one kind is called a pure substance.ex-carbon, chlorine,iron,copper and all the elements and compounds are pure substances.

Que-4 What is impure substance (mixture)?

Ans-Thoes substance which contains particles of different kinds is called an impure substance.(atoms and molecules)a mixture contains two or more pure substances mixed together ex-salt solution,sugar solution,milk,sea-water and all the mixtures are impure substances.

Que-5 What type of mixtures?

Ans-There are two type of mixtures:(i)Homogeneous mixture(ii)Heterogeneous mixture.

Que-6 What is Homogeneous mixture?

Ans-Thoes mixtures in which the substances are completely mixed together and are indistinguishable from one another, are called homogeneous mixtures.ex-Copper sulphate solution,sugar solution,salt solution etc.

Que7: What is Heterogeneous mixtures?

Ans-Thoes mixtures in which the substances remain seprate and one substance is spread throughout  the other substance as small particles,droplets or bubbles,are called heterogeneous mixtures.ex-Chalk and water solution,sugar and sand solution ect.

Que-8 List the points of differences between homogeneous and heterogeneous mixtures?

Ans-

Homogeneous mixtures:Mixtures having uniform composition are called homogeneous mixtures.For ex-mixture of salt in water,mixture of sugar in water and mixture of alcohol in water.

Heterogeneous mixtures:Mixture having non uniform composition are called heterogeneous mixtures.For ex-mixture of salt and sugar,mixture of sand and salt.

Que-9 How many classes all the matter can divided?

Ans-All the matter can divided into three general classes:(i)ELEMENT (ii)COMPOUNDS (iii)MIXTURES.

Que-10 What is malleability?

Ans-The property which allows the metals to be beaten into thin sheets is called malleability.

Que-11 What is ductility?

Ans-The property which allows the metals to be drawn into thin sheets is called ductility.

Que-12 What is elements?

Ans-An element is a substance which is made up of only one kind of atoms.For ex-copper and iron.

Que-13 How many groups the elements are divided?

Ans-All the elements can be divided into three groups:(i)Metals (ii)Non-metals (iii)Metalloids

Que-14 Define the metals and write its properties?

Ans-A metal is an element that is malleable and ductile,and good conducts of electricity.

Properties of metals:

(i)Metals are Malleable

(ii)Metals are Ductile

(iii)Metals are good conductors of heat and electricity.

(iv) Metals are Lustrous(or shiny),and can be polished

(v) Metals are generally hard

(vi) Metals are usually strong.they have high tensile strength.

Que-15 Define the non-metals and write its properties?

Ans-A non-metals is an element that is neither malleable nor ductile,and does not conduct electricity.

Properties of non-metals:

(i)Non-metals are not malleable,Non-metals are brittle

(ii)Non-metals are not ductile

(iii)Non-metals are bad conductors of heat and electricity (iv)Non-metals are Not lustrous(Not Shiny).They are dull in appearance(v)Non-metals are Generally Soft(vi)Non-metals are Not Strong.They Have Low Tensile strength

Que-16 What is metalloids?

Ans-The elements which show some properties of metals and some otjer properties of non-metals are called metalloids.ex-Boron,Silicon,Germanium etc.

Que-17 How would you confirm that a colourless liquid given to you is pure water?

Ans-The colourless liquid has fixed boiling point 100®C freezing point 0®C then it is pure water.

Que-18 Classify each of the following as a homogeneous and heterogeneous mixture:Soda water,air,wood,soil,vinegar,fitered tea?

Ans-Homogeneous mixture:Soda water,vinegar and filtered tea.Heterogeneous mixture:Wood,air and soil.

Que-19 What did you mean by mixture?

Ans- A mixture is a substance which consists of two or more elements or compounds not chemically combined together.All the solution are mixtures.

Que-20 What is compounds?

Ans-A compounds is a substance made up of two or more elements chemically combined in a fixed proportion by mass.ex-Ammonia,Carbon dioxide,steam,ice,calcium carbonate etc.

Que-21 What is alloys?

Ans-Alloys are homogeneous mixtures of metals and cannot be separated into their components by physical methods an alloy is considered a mixture.

Que-22 What is solutions?

Ans-A solution is a homogeneous mixture of two or more substance.ex-Salt solution,Sugar solution,vinegar,metal and alloys.

Que-23 What is suspensions?

Ans-A suspension is a heterogeneous mixture in which the small particles of a solid are spread throughout a liquid without dissolving in it.ex-Sand particles suspended in water,and flour in water.

Que-24 What is colloids?

Ans-A colloids is a kind of solution in which the size of solute particles is intermediate between those in ture solutions and those in suspensions.ex-Soap solution,Starch solution,Milk,Ink,Blood,Jelly ect.

Que-25 What is tyndall effect?

Ans-The scattering of light by colloidal particles is known as Tyndall effect.

Que-26 What is solvent?

Ans-The liquid in which solute is dissolved is known as solvent.ex-copper sulphate etc.

Que-27 What is solute?

Ans The substance which is dissolved in a liquid to make a solution is called solute.ex-salt solution etc.

Que-28 Write the classification of colloids?

Ans-(i)sol,(ii)solid sol,(iii)aerosol,(iv)emulsion,(v)foam,(vi)solid foam,(vii)gel

Que-29 What is concentration of a solution?

Ans-The concentration of a solution is the amount of solute present in a given quantity of the solution.the concentration of a solution is defined as the mass of solute in grams present in 100 gram of the solution.

Que-30 How many types of solutions?

Ans-There are two types of solution are:(i) SATURATED solution (ii) UNSATURATED solution.

Que-31What is saturated solution?

Ans-A solution in which no more solute can be dissolved at that temperature,is called a saturated solution.ex-an aqueous salt solution.

Que-32 What is unsaturated solution?

Ans-A solution in which more quantity of solute can be dissolved without raising its temprature,is called an unsaturated solution.

Que-33What is solubility?

Ans-The maximum amount of a solute which can be dissolved in 100 grams of a solvent at a specified temperature is known as the solubility of that solute in that solvent (at that temperature).

Que-34 Which sepration techniques will you apply for the separation of the following?

(i)sodium chloride from its soltion on water.(ii)Ammonium chloride from a mixture comtaining sodium chloride and ammonium chloride.

 

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