A abampere (aA) The unit of electric current in the CGSeniu system, defined as that current that, if flowing through two parallel conductors of negligible cross section and infinite length, placed 1 cm apart in vacuo, would produce on each conductor a force of 1 dyne per centimeter of length. 1 abampere = 1 abcoulomb/s = r statampere (where c = speed of light in cm/s) = 10 ampere. aberration Imperfect image formation due to geometric imperfections in the optical elements of a system ablation 1 . The wasting of glacier ice by any process (calving, melting, evaporation, etc.). 2. The shedding of molten material from the outer sur- face of a meteorite or tektite during its flight through the atmosphere. absolute age The age of a natural substance, of a fossil or living organism, or of an artifact, obtained by means of an absolute dating method. See absolute dating method. absolute density Density in kg/m' or, more commonly, in g/cm\ both at STP. Cf. density, relative density abso
Is Matter Around us Pure? CLASS 9 CHEMISTRY MCQ & SAQ
Is Matter Around us Pure? CLASS 9 CHEMISTRY NCERT SOLUTION:
Ques.1. What is meant by a pure substance?
Ans: A pure substance is one that is made up of only one kind of particles either atoms or molecules. For example, oxygen, carbon, etc.
Ques.2. List the points of differences between homogeneous and heterogeneous mixtures.
Ans:
Page No. 18
Q.1. Differentiate between homogeneous and heterogeneous mixtures with examples.
Ans:
Ques.2. How are sol, solution and suspension different from each other?
Ans:
Q.3. To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.
Ans: Mass of solute (sodium chloride) = 36 g (Given)
Mass of solvent (water) = 100 g (Given)
Then, mass of solution = Mass of solute Mass of solvent
= (36 100) g
= 136 g
Page No. 24
Q.1. How will you separate a mixture containing kerosene and petrol (the difference in their boiling points is more than 25°C), which are miscible with each other?
Ans: Distillation is used to separate a mixture of kerosene oil and petrol.
1. Take the mixture of petrol and kerosene in a round bottom flask and set the apparatus as shown in the diagram.
2. Heat the flask till petrol changes into vapors.
3. Vapors of petrol will condense and petrol will be collected in a flask.
4. Now heat the mixture again so that kerosene oil changes into vapors.
5. Vapors of kerosene will get condensed and collect kerosene oil into another flask.
Q.2. Classify the following as chemical or physical changes:
• Cutting of trees
• Melting of butter in a pan
• Rusting of almirah
• Boiling of water to form steam
• Passing of electric current through water, and water breaking down into hydrogen and oxygen gas
• Dissolving common salt in water
• Making a fruit salad with raw fruits
• Burning of paper and wood
Ans:
• Cutting of trees → Physical change
• Melting of butter in a pan → Physical change
• Rusting of almirah → Chemical change
• Boiling of water to form steam → Physical change
• Passing of electric current through water, and water breaking down into hydrogen and oxygen gas → Chemical change
• Dissolving common salt in water → Physical change
• Making a fruit salad with raw fruits → Physical change
• Burning of paper and wood → Chemical change
Ques.3. Name the technique to separate
(i) butter from curd, (ii) salt from sea-water, (iii) camphor from salt.
Ans. (i) Centrifugation (ii) Evaporation (iii) Sublimation
Q.5. What type of mixtures are separated by the technique of crystallization?
Ans: The crystallization method is used to purify solids.
1. Classify the following as chemical or physical changes:
• Cutting of trees
► Physical change
• Melting of butter in a pan
► Physical change
• Rusting of almirah
► Chemical change
• Boiling of water to form steam
► Physical change
• Passing of electric current through water, and water breaking down into hydrogen and oxygen gas
► Chemical change
• Dissolving common salt in water
► Physical change
• Making a fruit salad with raw fruits
► Physical change
• Burning of paper and wood
► Chemical change
Page No. 28
Ques.1. Which separation techniques will you apply for the separation of the following?
(a) Sodium chloride from its solution in water.
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.
(c) Small pieces of metal in the engine oil of a car.
(d) The different pigments from an extract of flower petals.
(e) Butter from curd
(f) Oil from water
(g) Tea leaves from tea
(h) Iron pins from sand
(i) Wheat grains from husk.
(j) Fine mud particles floating in water.
Ans. (a) Distillation
(b) Sublimation
(c) Filtration
(d) Chromatography
(e) Centrifugation
(f) Separating funnel
(g) Filtration
(h) Magnetic separation
(i) Winnowing
(j) Filtration.
Q.2. Write the steps you would use for making tea. Use the words:
solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
Ans: Take 100 ml of water which acts as solvent. Boil water with the help of a gas stove. Now add one spoon of sugar which gets dissolved as it is soluble in water, acts as solute, and forms a solution. Now add half a spoon of tea leaves which are insoluble in water. Let it boil for 2-3 minutes. Add half cup of milk and let it boil again for 3-4 minutes. Filter the tea with the help of a sieve. Tea leaves will be left as residue whereas tea will be obtained as filtrate.
Q.3. Pragya tested the solubility of three different substances at different temperatures and collected the data as given below( results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution)
(a) What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?
(b) Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.
(c) Find the solubility of each salt at 293 K. What salt has the highest solubility at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?
Ans: (a) At 313 K, 62 g of KNO3 is dissolved in 100 g of water. 31 g of salt will be dissolved in 50 g of water.
(b) Crystals of KCL will be formed when a hot saturated solution is cooled.
(c ) The solubility of KNO3 is 32 g, NaCl is 36 g, KCI is 35 g and NH4CI is 37 g per 100 g of water at 20°C, i.e. at 293 K. NH4CI has highest solubility.
(d) The solubility of salts increases with increase in temperature.
Q.4. Explain the following giving examples:
(a) Saturated solution
(b) Pure substance
(c) Colloid
(d) Suspension
Ans: (a) Saturated solution: A solution in which no more solute can be dissolved at a particular temperature is called saturated solution.
(b) Pure substance: They have uniform composition and always have the same properties like texture and taste, e.g. water, sodium chloride, sugar, oxygen.
(c) Colloid: The solution in which the particle size is between 1 nm, i.e. 10-9 m and 1,000 nm, i.e. 10-6 m, i.e. solute particles are 10 to 1,000 times bigger than the size of a single small molecule is called a colloid. The particles are smaller than those in suspension.
(d) Suspension: It is a heterogeneous mixture in which solid particles, which are insoluble in the solvent, remain suspended in the bulk of the medium and are visible to the naked eye.
Example: Muddy river water, chalk powder in water, sulfur powder in water, limestone particles in water, barium sulfate in water, dust storm.
Ques.5. Classify each of the following as a homogeneous or heterogeneous mixture.
Soda water, wood, air, soil, vinegar, filtered tea.
Ans: Homogeneous mixtures: Soda water, air, vinegar.
Heterogeneous mixtures: Wood, soil, filtered tea.
Ques.6. How would you confirm that a colorless liquid given to you is pure water?
Ans: • Take the given liquid in a boiling tube fitted with a cork.
• Suspend a thermometer into it so that it remains above water.
• Place the boiling tube on a wire gauze and start heating with the help of a burner.
• Note down the temperature at which water changes into vapors completely and the temperature of the thermometer remains constant.
Observation: The given liquid boils at 100°C i.e., 373 K.
Conclusion: The given liquid is pure water because pure water boils at 100°C i.e., 373 K.
Ques.7. Which of the following materials fall in the category of a "pure substance"?
(a) Ice
(b) Milk
(c) Iron
(d) Hydrochloric Acid
(e) Calcium oxide
(f) Mercury
(g) Brick
(h) Wood
(i) Air
Ans: The following materials fall in the category of a "pure substance":
(a) Ice
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
Ques.8. Identify the solutions among the following mixtures:
(a) Soil
(b) Seawater
(c) Air
(d) Coal
(e) Soda water
Ans: The following mixtures are solutions:
(b) Seawater
(c) Air
(e) Soda water
Ques.9. Which of the following will show the "Tyndall effect"?
(a) Salt solution
(b) Milk
(c) Copper Sulfate solution
(d) Starch solution
Ans: Milk and starch solution will show Tyndall effect because these are colloidal solutions in which the path of light becomes clearly visible due to scattering of light.
Ques.10. Classify the following into elements, compounds and mixtures:
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
(f) Tin
(g) Silicon
(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood
Ans:
Ques.11. Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of candle
Ans: The following changes are chemical changes:
(a) Growth of a plant
(b) Rusting of iron
(d) Cooking of food
(e) Digestion of food
(g) Burning of candle.
Is Matter Around us Pure? CLASS 9 CHEMISTRY MCQ
1. Name the mixture whose particles are large enough to scatter light.
(a) Colloid
(b) True solutions
(c) Homogeneous solution
(d) All of the above
► (a) Colloid
2. Which of the following properties does not describe a compound?
(a) It is composed of two or more elements
(b) It is a pure substance.
(c) It cannot be separated into constituents by physical means
(d) It is mixed in any proportion by mass
► (d) It is mixed in any proportion by mass
3. The components of a solution are:
(a) Dispersed particles and solvent
(b) Solute and solvent
(c) Dispersed phase and dispersion medium
(d) Solute and dispersed medium
► (b) Solute and solvent
4. The smell of hydrogen sulfide (H2S) gas
(a) pleasant
(b) of rotten egg
(c) of burning sulfur
(d) None of these
► (b) of rotten egg
5. Which of the following substances will not dissolve in water?
(a) Sugar
(b) Sodium chloride
(c) Copper sulfate
(d) Carbon
► (d) Carbon
6. What is the principle behind the process of centrifugation?
(a) Particles are separated based on the difference in color.
(b) Denser particles are forced to the bottom and lighter particles stay at the top when spun rapidly.
(c) Lighter particles are forced to the bottom and denser particles stay at the top when spun rapidly.
(d) Particles are separated based on the difference in temperature.
► (b) Denser particles are forced to the bottom and lighter particles stay at the top when spun rapidly.
7. What will you observe when a mixture of iodine and salt is heated in a china dish?
(a) No change in the china dish is observed.
(b) Salt is left behind in the china dish.
(c) Iodine is left behind in the china dish.
(d) The mixture starts melting.
► (b) Salt is left behind in the china dish.
8. An example of a liquid metal and a liquid non-metal is
(a) gallium, mercury
(b) mercury, chlorine
(c) mercury, bromine
(d) bromine, sulfur
► (c) mercury, bromine
9. Which technique is used in diagnostic laboratories for blood and urine tests?
(a) Sublimation
(b) Centrifugation
(c) Evaporation
(d) Magnetic separation
► (b) Centrifugation
10. Which method is used to separate cream from milk?
(a) Centrifugation
(b) Adsorption
(c) Distillation
(d) Crystallization
► (a) Centrifugation
11. Which of the following is a chemical change?
(a) Melting of wax
(b) Mixing of iron filings with sulfur powder
(c) Cooking of food
(d) Dissolving salt in water
► (c) Cooking of food
12. The continuous zig-zag movement of colloidal particles in a dispersion medium is called
(a) Dispersion
(b) Tyndall effect
(c) Brownian movement
(d) Oscillation
► (c) Brownian movement
13. A change of state from one form to another is a
(a) physical change
(b) chemical change
(c) biological change
(d) state variation
► (a) physical change
14. The formation of water from oxygen and hydrogen is a _______ .
(a) Physical change
(b) Chemical change
(c) Reversible change
(d) Both Physical and Reversible change
► (b) Chemical change
15. What do you understand by the term concentrated solution?
(a) Solution containing no solute
(b) Solution with low solute concentration
(c) Solution in which no more solute can be dissolved
(d) Solution with high solute concentration
► (d) Solution with high solute concentration
16. The clear liquid which is left behind in the beaker after settling down of the sediments is called:
(a) Solvent
(b) Supernatant liquid
(c) Solution
(d) Sediment
► (b) Supernatant liquid
17. Which of the following parameters of a substance does not alter during a physical change?
(a) State
(b) Mass
(c) Volume
(d) Size
► (b) Mass
18. Which of the following statements is incorrect about physical changes?
(a) There is no gain or loss of energy.
(b) It is permanent and irreversible.
(c) Composition of the substance remains the same.
(d) No new substance is formed.
► (b) It is permanent and irreversible.
19. A colloid with a solid dispersed phase and liquid dispersing medium is called:
(a) Foam
(b) Gel
(c) Sol
(d) Emulsion
► (c) Sol
20. Which technique is used to separate blood cells from plasma?
(a) Evaporation
(b) Sublimation
(c) Centrifugation
(d) Filtration
► (c) Centrifugation
21. A solution in which no more solute can be dissolved at a given temperature is known as:
(a) Unsaturated solution
(b) True solution
(c) Dilute solution
(d) Saturated solution
► (d) Saturated solution
22. Which of the following apparatus is not required in sublimation?
(a) Condenser
(b) Funnel
(c) China dish
(d) Wire gauze
► (a) Condenser
23. Which of the following methods can be used to separate a mixture of camphor and sugar?
(a) Sublimation
(b) Filtration
(c) Distillation
(d) Crystallization
► (a) Sublimation
24. The process of separation of insoluble solids from a liquid is called:
(a) Filtration
(b) Decantation
(c) Crystallization
(d) Evaporation
► (a) Filtration
25. If a solution contains 60g of common salt in 340g of water, the mass by mass percentage will be:
(a) 25 %
(b) 15 %
(c) 20 %
(d) 17.6 %
► (b) 15 %
26. During sublimation of ammonium chloride, pure ammonium chloride gets:
(a) Liquefies to form a solution
(b) Collected on outer sides of the funnel
(c) Collected on inner sides of the china dish
(d) Collected on inner sides of the funnel
► (d) Collected on inner sides of the funnel
27. What type of change takes place when a sodium hydroxide pellet is added to water?
(a) Reversible change
(b) Reversible chemical change
(c) Physical change
(d) Chemical change
► (d) Chemical change
28. During filtration, the solid that remains on the filter paper is called:
(a) Solute
(b) Residue
(c) Solvent
(d) Filtrate
► (b) Residue
29. Which of the following has the highest solubility at 313 K?
(a) KNO3
(b) NaCl
(c) KCl
(d) NH4Cl
► (a) KNO3
30. A chemical reaction involves in
(a) Only breaking of bonds
(b) Only formation of bonds
(c) Both breaking and formation of bonds
(d) None of these
► (c) Both breaking and formation of bonds
31. Which of the following colloids is a gel?
(a) Fog
(b) jellies
(c) Milk
(d) Smoke
► (b) jellies
32. What is the use of a sedimentation tank in a water purification system?
(a) To separate out the insoluble substances from water.
(b) To separate out very small suspended particles from water.
(c) To kill the germs present in water.
(d) All of the above.
► (a) To separate out the insoluble substances from water.
33. Which of the following statements is true for colloids?
(a) Colloid is a homogeneous mixture.
(b) Particles of a colloid can be seen by naked eye.
(c) Particles of colloid scatter a beam of light passing through it.
(d) All of these
► (c) Particles of colloid scatter a beam of light passing through it.
34. Which of the following is not a mixture?
(a) Soap solution
(b) Blood
(c) Carbon dioxide
(d) Coal
► (c) Carbon dioxide
35. What type of mixture is obtained on continuous stirring when we add one spoon of sugar to water?
(a) Homogeneous mixture
(b) Colloid
(c) Suspension
(d) Heterogeneous mixture
► (a) Homogeneous mixture
36. Which of the following is a true solution?
(a) Milk
(b) Chalk powder in water
(c) Salt solution
(d) Blood
► (c) Salt solution
37. Most paints are:
(a) Gels
(b) Suspensions
(c) Emulsions
(d) Sols
► (d) Sols
38. Which is the best technique to separate coffee grains from coffee solution?
(a) Distillation
(b) Evaporation
(c) Filtration
(d) Chromatography
► (c) Filtration
Is Matter Around us Pure? CLASS 9 CHEMISTRY SAQ:
Question 1. Define solvent.
Answer: The component of the solution that dissolves the other component in it is called the solvent.
Question 2. Define solute.
Answer: The component of the solution that is dissolved in the solvent is called solute.
Question 3. What is ‘tincture of iodine’?
Answer: A solution of iodine in alcohol is known as tincture of iodine. It has iodine (solid) as the solute and alcohol (liquid) as the solvent.
Question 4. What are alloys?
Answer: The homogeneous mixture of two or more metals or a metal and non-metal is called an alloy. E.g., steel is an alloy of iron and carbon.
Question 5. Give one example of gas in liquid solution.
Answer: Cold-drinks, carbon dioxide gas as solute is mixed with water as a solvent.
Question 6. How can a solution be dilute or concentrated?
Answer: The amount of solute dissolving in a solvent decides whether the solution is dilute or concentrated.
Question 7. What is “concentration of a solution”?
Answer: The concentration of a solution is the amount of solute present in a given amount of solution or the amount of solute dissolved in a given mass or volume of solvent.
Question 8. State the difference between aqueous and non-aqueous solutions.
Answer: Aqueous solutions have water as solvent and non-aqueous solutions do not haVe water as solvent.
Question 9. What is the “solubility” of a solute?
Answer: The amount of the solute present in the saturated solution at the given temperature is called its solubility.
Question 10. What is a saturated solution?
Answer: The maximum amount of solute dissolved in a solvent at given temperature is called saturated solution, where no more solute can dissolve further.
Question 11. What is an unsaturated solution?
Answer: If the amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.
Question 12. How can you convert saturated solution into unsaturated or vice-versa?
Answer: Saturated solution on heating becomes unsaturated and unsaturated solution on cooling becomes saturated.
Question 13. Why is water called a universal solvent?
Answer: Water can dissolve large numbers of substances in it.
Question 14. What is the Tyndall effect?
Answer. The scattering of light by colloidal particles is known as the Tyndall effect.
Question 15. How can we separate colloidal mixtures?
Answer: By centrifugation, in a centrifuge machine the colloidal solution is kept in a test tube, rotated very fast and due to centrifugal force the colloidal particles are separated.
Question 16. What is emulsion?
Answer: When both the dispersed phase and dispersing medium is liquid, it is called emulsion. E.g., milk, face cream.
Question 17. What is aerosol?
Answer. When the solid or liquid is dispersed in a gas it is called aerosol. E.g., smoke, fog.
Question 18. What is the principle for separation of immiscible liquids?
Answer: The principle of separating immiscible liquids into layers depending on their densities. The less dense liquid collects at the top and more dense liquid at the bottom. ‘
Question 19. What is chromatography?
Answer: Chromatography is the technique used for separation of those solutes that dissolve in the same solvent.
Question 20. What is distillation?
Answer: Distillation is the separation technique of two miscible liquids that boils without decomposition and have sufficient difference in their boiling points.
Question 21. How can you separate two liquids that have less than 25 K difference of boiling points?
Answer: To separate a mixture of two or more miscible liquids for which the difference in boiling points is less than 25 K, is fractional distillation.
Question 22. What is a condenser?
Answer: It is an apparatus used to convert gas into liquid by cooling it.
Question 23. What is crystallization?
Answer: When a saturated solution is heated and allowed to cool slowly, crystals of the solute dissolved in the saturated solution are separated from it. It is used to purify solids.
State the properties of a solution.
Answer: Properties of a solution are:
A solution is a homogeneous mixture.
Particles of a solution are smaller than 1 nm and cannot be seen by naked eyes.
Do not scatter beams of light.
Solute particles cannot be separated from the mixture by the process of filtration and thus, the solution is stable.
Question 5. State the properties of a suspension.
Answer: Properties of a suspension
Suspension is a heterogeneous mixture having particle size greater than 100 nm.
The particles of a suspension can be seen by naked eyes.
Particles can scatter a beam of light.
It is unstable.
Question 6. What is a colloidal solution?
Answer: It is a heterogeneous solution which appears to be homogeneous, particles size is very small and so cannot be seen with naked eyes but it is stable. E.g., milk and blood.
Question 7. State the properties of colloidal solution.
Answer: Properties of colloidal solution.
It is a heterogeneous mixture having particle size between 1 nm to 100 nm.
Size of particles is very small, and cannot be seen with naked eyes.
It scatters a beam of light.
They are stable as the particles do not settle when left undisturbed.
Question 8. Give the applications of centrifugation.
Answer: Application of centrifugation are:
Used in diagnostic laboratories for blood and urine tests.
Used in dairies and home to separate butter from cream.
Used in washing machines to squeeze out water from wet clothes.
Question 9. Give the applications of chromatography.
Answer: Applications of chromatography are
To separate colors in a dye.
To separate pigments from natural colors.
To separate drugs from blood.
Question 10. Why is crystallization better than evaporation?
Answer: Crystallization is a process that separates a pure solid in the form of its crystals from a solution. Crystallization is better than evaporation because during Evaporation
Some solids decompose or some, like sugar may get charred on heating to dryness.
Some impurities may remain dissolved in the solution even after filtration which on evaporation contaminates the solid.
Question 11. How will you separate a mixture of oil and water?
Answer: To separate a mixture of oil and water, we need a separating funnel as both are immiscible liquids. Pour the mixture in the separating funnel and let the funnel stand undisturbed for some time. So that separate layers of oil and water are formed. Open the stopcock of the separating funnel and pour out the lower layer of water carefully.
Question 12. A student is given a mixture of naphthalene ball’s powder and common salt. He needs to separate this mixture. How will he do this?
Answer: The properties of both naphthalene and common salt should be known, before we choose the separation technique.
Naphthalene is a sublimate which on heating changes to gaseous state directly. Hence to separate a volatile compound (sublimate) from a non-volatile compound (non-sublimate), the sublimation process is used.
In a China dish the mixture is kept, and is placed on a stand. An inverted funnel is kept over the mixture in a Chinese dish with a plugged stem. The sublimation on heating gets collected on the funnel and common salt remains in the China dish.
Question 13. How can we obtain different gasses from air?
Answer: Air is a homogeneous mixture and its components can be separated by fractional distillation.
Question 14. Draw a flow diagram to show the water purification system in water works.
Answer:
In filtration tank water passes through different layers of sand and gravel as shown in the above figure this is for adsorption of impurities.
The clear water reaches a chlorinated tank where water is mixed with bleaching powder/chlorine to kill bacteria and then supplied to houses.
Question 15. Why is air considered as a mixture and not compound?
Answer: Air is considered as a mixture because it exhibits following properties:
Each component present in air retains its properties.
Each component can be separated by simple physical processes.
The components do not have any fixed proportion. All gasses are present in different amounts. Example, in a greener area—more oxygen and water vapor is present; near an industrial area—air consists of a lot of impurities and smoke suspended in it.
Question 16. How can you prove that water is a compound?
Answer: Water is a compound because if we pass electricity through it then at two different electrodes, we get two different gasses i.e., oxygen and hydrogen during electrolysis of water. The ratio of oxygen: hydrogen is 1 : 2 by the number of molecules.
The properties of oxygen and hydrogen gasses are entirely different from that of liquid water.
The ratio of oxygen: hydrogen combination is always constant i.e., 1: 2 by volume.
To separate the components of water, we need an electrolytic cell, and it is not a simple process.
Question 17. How can we convert saturated solution into unsaturated by heating?
Answer: Saturated solution is said to be saturated at a given temperature when there is no more scope of solute particles to dissolve /dissociate into water. It is because the solute particle has taken all the inter molecular space present in the solvent.
On heating, the molecules of solvent gain kinetic energy, start vibrating and try to move away from each other thereby accommodating some more solute particle in this space and hence it becomes an unsaturated solution.
Question 18. What is the difference between fog and smoke?
Answer: Fog is a colloidal solution with liquid dispersed in gas.
Smoke is a colloidal solution with solid dispersed in gas.
Question 19. If 20g of salt is present is 220 g of solution, calculate the concentration of solution:
Is Matter Around us Pure? CLASS 9 CHEMISTRY long question:
Question 1. Give the difference between true solution, colloidal solution and suspension.
Answer: The difference between true solution, colloidal solution and suspension
Question 2. State the different types of colloids with examples.
Answer: Different colloids are formed due to different dispersed phase and dispersing
Question 3. (a) Define a solution.
(b) Give different types of solutions with one example each.
Answer: (a) Solution: It is a homogeneous mixture of two or more substances. It consists of solute and solvent.
(b) Different types of solution:
(i) Based on solvent—Aqueous and non-aqueous Aqueous solution has water as solvent (sugar + water) Non-aqueous solution has some other solvent but not water. Example, (sulfur + carbon disulphide)
(ii) Depending on the amount of solute dissolved in solvent—Dilute solution and concentrated solution
Dilute solution—Less amount of solute particles are present in a solvent.
Concentrated solution—Amount of solute present in its maximum capacity in a solvent.
(iii) Amount of solute present in its maximum capacity at a given temperature—Saturated and unsaturated solution.
Saturated solution—It is a solution in which no more solute can further dissolve in a given solvent at a given temperature.
Unsaturated solution—It is a solution in which some more solute can dissolve in a solvent at a given temperature.
(iv) Depending on the size of solute particles
Question 4. How can you separate the following mixtures?
(a) Sand + iron (b)Cream from milk
(c) Salt + water (d) Ammonium chloride + NaCl
(e) Copper sulfate + water (f) Rice and dal (uncooked)
(g) Gasses from air (h) Petrol and diesel from crude oil
(i) Drugs from blood (j) Acetone from water
Answer:
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