Frank ICSE Class 9 Chemistry Solutions

Frank ICSE Solutions for Class 9 Chemistry – Atmospheric Pollution

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Frank ICSE Solutions for Class 9 Chemistry – Atmospheric Pollution

PAGE NO :158
Solution 1:
Acid rain is the rain that has an excessive amount of acid in it than that of normal. Two air pollutants that cause acid rain are-

    1. Oxides of nitrogen
  1. Oxides of sulphur

Solution 2:
Acid rain is responsible for retarding forest’s growth and other vegetation. Acid rain makes the soil acidic and adversely affects the plants.

Solution 3:
70% of acid rain is due to sulphur dioxide. Oxides of sulphur and nitrogen released into atmosphere from number of sources.These oxides of nitrogen gets converted into nitrogen dioxide(NO2) which reacts with water to form nitric acid.Similarly, sulphur dioxide reacts with atmospheric oxygen to form sulphur trioxide which with water forms sulphuric acid.These come down on earth as acid rain.

Solution 4:
Acid rain can be reducd by-

  1. There should be reduction in fossil fuel combustion.
  2. Use of alternate cleaner energy sources should be encouraged. Eg-nuclear power, hydro power, wind energy, solar energy etc.
  3. Air filters and scrubbers are fitted in tall industrial chimneys to control air pollution.
  4. Catalytic converters in vehicle reduce nitrogen oxide emissions from automobiles.

Solution 5:

Acid rain cause extensive damage to the environment.

  1. Vegetation – The acid rain makes the soil acidic. This adversely affects the plants and animals. This damages leaves of plants and trees. This is responsible for retarding forests and other vegetation.
  2. Fertility of soil – The activity of symbiotic nitrogen fixing bacteria present in the nodules of leguminous family is inhibited. This is responsible for destroying or reducing the fertility of the soil.
  3. Water bodies – Acid rain renders the river, lakes or even ocean water acidic, there by adversely affecting marine animals. Changes in pH affect the reproduction and survival of many species of fish and other animals.
  4. Buildings and monuments – Acid rain cause extensive damage to the buildings and monuments made from marbles, limestone, slate and mortar.
    Frank ICSE Solutions for Class 9 Chemistry - Atmospheric Pollution 1
  5. Ecological balance – Acid rain is responsible for wiping out many bacterial and blue green algae, so disrupting the whole ecological balance.
  6. Human health – Acid rain has been found to be dangerous to human health. Acidic conditions can affect human nervous, respiratory and digestive systems.

Solution 6:
Air pollution is a harmful change in the natural air quality. It includes all physical, chemical and biological agents that modify the natural characteristics of the atmosphere.

Solution 7:
Ozone is an allotrope of oxygen. It has three oxygen atoms and its molecular formula is O3.It is an unstable blue gas having pungent odour found in troposphere. It is used as a powerful oxidant, bleach and water purifier.

Solution 8:
The gases causing ozone depletion are-

  1. Chlorofluoro carbons(CFCs or freons)
  2. Methane
  3. Nitrous oxides
  4. Carbon tetrachloride
  5. Methyl bromide(a soil fumigant and insecticide)
  6. Aircraft emission
  7. n-propyl bromide and Halon-1202

Solution 9:
Greenhouse gases are-

  1. Water vapour(H2O)
  2. Carbon dioxide(CO2)
  3. Methane(CH4)
  4. Oxides of nitrogen(NOx)

Solution 10:
Frank ICSE Solutions for Class 9 Chemistry - Atmospheric Pollution 2

Solution 11:
Greenhouse effect means the progressive warming up of the earth’s surface due to the blanketing effect of man made carbon dioxide in the atmosphere. Greenhouse is a glasshouse with plants inside and  which allows short wave, incoming solar radiation to come in but does not allow the long wave,i.e. outgoing  infrared radiation to escape from inside the structure. Some of the gases in the earth’s atmosphere act like the glass in a greenhouse.They trap sun’s heat and keep the surface of the earth warm. Carbon dioxide and water vapour act as a greenhouse.

Solution 12:
Global warming is rise in the average global earth temperature . An increase in the average temperature of the earth’s atmosphere due to greenhouse effect  which can have far reaching effects on the climate and consequently on the key life, support systems of the planet, and this phenomenon is called global warming.

Solution 13:
Frank ICSE Solutions for Class 9 Chemistry - Atmospheric Pollution 3f

Solution 14:

  1. The warmer climate is changing the patterns of rainfall and snowfall.
  2. It causes increase in the frequency and severity of drought and flood also.
  3. It  is affecting our resources like water,forests  and different ecological systems.
  4. It also cause frequent natural disasters like cyclones, storms and hurricanes,floods and droughts.
  5. The global warming is damaging various ecosystems like mangrove-swamps , coral reefs and coastal lagoons, etc. due to various reasons like reduction in pH of oceanic water and increasing deposits of acids.
  6. It is damaging the world biodiversity. Vast varieties of birds, reptiles, insects, bacteria, fungi, rodents etc.have vanished out due to these effects.

Solution 15:
It has been found that in every southern spring(September-October) 50-95 %  of stratospheric ozone is destroyed at a height of 15-24 kms above ‘Antarctica’ creating pockets which have been described as ozone hole.

Solution 16:
The adverse effects of ozone layer depletion are-

  1. UV radiation causes sun-eye diseases (cataract), skin diseases, skin cancer and damage to immune system in our body.
  2. It damages plants and causes reduction in crop productivity.
  3. It damages embryos of fish, shrimps, crabs and amphibians.
  4. UV radiation damage fabrics, pipes, paints and other non-living materials on this earth.
  5. It contributes in the global warming. If the ozone depletion continues, the temperature around the world may rise at faster rate and to a large extent.

Solution 17:
Natural greenhouse effect is a process of thermal blanketing of the earth which maintains its temperature to sustain life on it. Without greenhouse effect, the climate of the earth would be too cold for most of the life to survive.

Solution 18:
The effect of warming and insulation of the earth caused due to some heat trapping gases accumulated in the atmosphere after their emission from the earth surface is called as greenhouse effect. Due to this there is rise in the average global earth temperature called global warming.

Solution 19:
When an ozone molecule is hit by UV wavelengths, it absorbs the radiant energy and photo dissociates into O2 and O giving off heat. Thus, keeps the UV radiation from reaching the earth’s surface and also causes a temperature inversion in the stratosphere that helps to maintain relatively stable climatic conditions on and near the ground.

Solution 20:
When an ozone molecule is hit by UV wavelengths, it absorbs the radiant energy and photo dissociates into O2 and O giving off heat. Thus, keeps the UV radiation from reaching the earth’s surface and also causes a temperature inversion in the stratosphere that helps to maintain relatively stable climatic conditions on and near the ground.

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Frank ICSE Solutions for Class 9 Chemistry – Practical Work

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Frank ICSE Solutions for Class 9 Chemistry – Practical Work

PAGE NO :170
Solution 1:
On heating certain solids they don’t melt and directly get converted to their gaseous form, this process of direct conversion of solids to their gaseous form is called as sublimation. For ex: camphor and ammonium chloride undergo sublimation.

Solution 2:
Decrepitation is a process of breaking up of solid particles on heating, which makes a crackling sound. Lead nitrate decrepitate on heating.
Frank ICSE Solutions for Class 9 Chemistry - Practical Work 6
Lead nitrate

Solution 3:
(a) Zn(NO)3        = white
(b) Cu(NO3)2      = blue
(c) CuSO4.5H2O  = blue
(d) CuSO4          = pale green
(e) K2Cr2O7       = orange
(f) PbS               = black

Solution 4:
Frank ICSE Solutions for Class 9 Chemistry - Practical Work 1

Solution 5:
Frank ICSE Solutions for Class 9 Chemistry - Practical Work 2

Solution 6:
Frank ICSE Solutions for Class 9 Chemistry - Practical Work 3

Solution 7:
Frank ICSE Solutions for Class 9 Chemistry - Practical Work 4

Solution 8:
(a) Rotten egg
(b) Burning sulphur
(c) Nitrogen dioxide
(d) Alkali
(e) Ca(OH)2
(f) Lilac
(g) Brick-red

Solution 9:
Point sources of water pollution: Sources of water pollution that discharge directly into the water source are called as point sources of water pollution.
For ex: factories
Non point sources of water pollution: sources of water pollution that remain scattered and don’t have specific locations for the discharge of pollutants into particular water bodies are called as non point sources of water pollution.
For ex: run off from fields.

Solution 10:
Frank ICSE Solutions for Class 9 Chemistry - Practical Work 5

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Frank ICSE Solutions for Class 9 Chemistry – Matter and its Composition: Law of Conservation of Mass

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Frank ICSE Solutions for Class 9 Chemistry – Matter and its Composition: Law of Conservation of Mass

PAGE NO :8
Solution 1:
Matter is anything around us which occupies space and has mass. Example- Coal, Copper, Water, Oxygen, Kerosene
Key: Matter occupies space and has mass.

Solution 2:
The conditions for something to be called matter are –

  1. It should occupy space.
  2. It should have mass.

Solution 3:
Light and sound are not considered to be matter because they neither have mass nor do they occupy space.

PAGE NO :9
Solution 4:
Solid:

  1. The particles are held together by strong intermolecular forces and have minimum intermolecular space.
  2. Solids have definite mass, shape and volume.

Liquid:

  1. The intermolecular forces of liquid molecules are intermediate of molecules  of solids and gases while intermolecular spaces are greater than in solids.
  2. Liquids have definite mass and volume but not definite shape. They take the shape of the container.

Gas:

  1. The particles are held together by very weak intermolecular forces while intermolecular spaces are much greater than in solids.
  2. Gases have definite mass but not definite shape and volume. They take the shape of the container.

Solution 5:
Two reasons for saying that wood is a solid are-

  1. Wood has definite mass and shape.
  2. Their intermolecular forces are very strong so they cannot flow.

Solution 6:
The particles of gases are separated from each other by large spaces and intermolecular forces of attraction are the weakest in gases. They have least density. So, they can flow easily. Hence, gases have no fixed shape and volume.
Key: Intermolecular forces of attraction are the weakest in gases.

Solution 7:

  1. Gases
  2. Solid
  3. Solid

Solution 8:

PropertiesSolidsLiquidsGases
1.State of packingThe particles are closely packed and their positions are also fixed.The particles are loosely packed and their positions are not fixed.The molecules are wide apart and their positions are also not fixed.
2.Energy associatedParticles can vibrate only to and fro about their mean positions. Therefore, they have small kinetic energy due to their motion.The particles can move about more freely and have considerable kinetic energy due to their motion.The particles move about freely and have maximum kinetic energy due to their motion.
3.Intermolecular forcesThe particles are held together by strong intermolecular forces.The particles are held together by weak intermolecular forces.The particles are held together by very weak intermolecular forces.
4.Physical featuresSolid has a crystalline structure with both definite size and definite shape.Liquid does not have a definite shape but has definite volume and can flow from higher to lower level.Gas has neither definite shape nor a definite volume but can flow and is easily compressible.

Solution 9:

  1. gases
  2. strong
  3. sublimation
  4. Condensation
  5. gaseous

Solution 10:
The postulates of the kinetic theory of matter-

  1. Composition of Matter: Matter, whether in the solid, liquid or gaseous state, is composed of very small particles which may be molecules, atoms or ions.
  2. Arrangement of Particles: These particles have spaces lying between them and these spaces are referred to as intermolecular spaces or interparticle spaces.
  3. Forces of Attraction: The forces of attraction between the molecules of a given substance are called intermolecular forces. The magnitude of this force depends upon the state of the substance and on the magnitude of the intermolecular spaces. As the intermolecular space increases, the intermolecular force decreases.
  4. Motion of the constituent particles: The particles are always in a state of motion. In solids, they vibrate about their mean positions and in liquids and gases, they move randomly.
  5. The kinetic energy of the particles increases with rise in temperature. As the temperature is increased, the particles undergo motion more vigorously and more  randomly.

Solution 11:

  1. Solid to liquid state: The conversion of a substance from the solid state to liquid state at a particular temperature is called melting or fusion. The heat energy supplied to the solid is absorbed by its molecules to gain kinetic energy. The kinetic energy increases the rate of vibration of the molecules. The force of attraction thus no longer holds the molecules close together and the solid gets change into liquid.
  2. Gas to liquid: The conversion of a substance from the gaseous state to its liquid state at a particular temperature is called condensation or liquefaction. On cooling, the gas molecules loose their kinetic energy in the form of lost heat and so molecular motion slows down. Decreased molecular motion causes a decrease in intermolecular space. The molecules come very close and the force of attraction between them correspondingly increases and the gas gets change into liquid.
  3. Liquid to gaseous state: The heat energy supplied to the liquid is absorbed by its molecules to gain kinetic energy and therefore the molecules move faster. This increases the intermolecular space. The intermolecular force of attraction decreases and liquid changes into gaseous state.
  4. Liquid to solid state: The conversion of a substance from the liquid state to solid state by cooling is called freezing. On cooling a liquid, the kinetic energy of the molecule is decreased. Due to decreased kinetic energy, the molecules cool down and come closer, thus reducing the intermolecular spaces. The force of attraction between the molecules thus increases. Now, the molecules are no longer in a position to be free or to migrate and liquid changes into a solid.

Solution 12:

  1. Freezing: The process of changing a liquid into a solid by cooling is called        freezing. Freezing means solidification. It occurs at a definite temperature called freezing point.
  2. Evaporation: The phenomenon involving the change of a substance from the liquid state to the gaseous state at room temperature or at any other temperature below its boiling point is called vaporization or evaporation.
  3. Boiling point: The temperature at which a liquid boils and changes rapidly into a gas at atmospheric pressure is called boiling point of the liquid.
  4. Melting point: The temperature at which a solid substance changes into its liquid state at 1 atmospheric pressure is called the melting point of that substance.

Solution 13:

  1. Size of naphthalene balls decreases – Sublimation
  2. Drying of wet clothes – Evaporation
  3. Wax melts in the sun – Melting
  4. Formation of clouds – Evaporation and Condensation

Solution 14:
Three compounds which are sublimate are-

  1. Camphor
  2. Naphthalene
  3. Iodine

Solution 15:
‘States of matter triangle’ shows inter-conversion of states of matters.
Frank ICSE Solutions for Class 9 Chemistry - Matter and its Composition Law of Conservation of Mass 1

Solution 16:
The process by which a liquid slowly converts into vapour state at a temperature below its boiling point is called evaporation.
The heat energy is absorbed by the liquid to convert it into vapour state. So, loss of heat causes cooling.

Solution 17:

  1. True
  2. True
  3. False
  4. True

Solution 18:
“In all physical and chemical changes, the total mass of the reactants is equal to that of the products”. So, in other words matter can neither be created nor destroyed.

Solution 19:
Frank ICSE Solutions for Class 9 Chemistry - Matter and its Composition Law of Conservation of Mass 2

Solution 20:

  1. Matter
  2. Solid
  3. Gas
  4. Solid
  5. Gas
  6. Gas
  7. Liquid
  8. Fluid
  9. Melting
  10. Vaporization

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Frank ICSE Solutions for Class 9 Chemistry – Study of Gas Laws

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Frank ICSE Solutions for Class 9 Chemistry – Study of Gas Laws

PAGE NO :21
Solution 1:
An ideal gas can be characterized by three state variables:

  1. Absolute pressure (P),
  2. Volume (V), and
  3. Absolute temperature (T).

Solution 2:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 1

Solution 3:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 2

Solution 4:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 19

Solution 5:
Kelvin zero is – 273.15 oC.

Solution 6:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 3

Solution 7:
The standard temperature and pressure (STP) by general convention are 0 oC(273 K) and 1 atm(760 mm Hg).

Solution 8:

  1. The value of standard temperature is (i) 0 oC and (ii) 273 K
  2. The value of standard pressure is (i) 1 atm, (ii) 760 mm of Hg, (iii)76 cm of Hg, (iv)760 torr

Solution 9:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 4

Solution 10:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 5
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 6

Solution 11:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 7

Solution 12:
There is simultaneous effect of temperature and pressure changes on the volume of a given mass of a gas. So, when stating the volume of a gas, the pressure and temperature should also be given.

PAGE NO :22
Solution 13:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 8

Solution 14:

  1. Volume of a gas would be reduced to zero at 0 K (-273 0C).All temperatures on the Kelvin scale are positive, so Kelvin scale has been adopted for chemical calculation.
  2. At absolute zero temperature, volume of a gas would be reduced to zero. Theoretically,this is the lowest temperature that can be reached. At this temperature all molecular motions cease. Thus, practically this temperature is impossible to attain because on cooling gases liquefy and Charles’ law is no more applicable.
  3. According to combined gas law equation, there is simultaneous effect of temperature and pressure changes on the volume of a given mass of a gas. So, when stating the volume of a gas, the pressure and temperature should also be given.

Solution 15:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 9

Solution 16:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 10

Solution 17:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 11

Solution 18:

  1. True
  2. False
  3. False
  4. False
  5. False

Solution 19:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 12

Solution 20:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 13

Solution 21:
We trap a definite quantity of  air in the closed vessel. At any point, the pressure on the air is equal to the atmospheric pressure plus the pressure due to the excess mercury column in the open end tube. By pouring mercury in the tube, we increase the pressure on the air and measure its volume under that pressure. We thus obtain a set of data for the volume of a fixed mass of air under different pressures.
For a given mass of air at constant temperature, the following observations are made-

  1. The volume of air decreases with increasing pressure and vice versa.
  2. The proportion by which the volume decreases or increases is the same by which the pressure increases or decreases.

Solution 22:

  1. Pressure will also be doubled.
  2. Pressure will be double.

Solution 23:

  1. 273
  2. absolute zero
  3. absolute temperature
  4. the average kinetic energy

Solution 24:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 14

Solution 25:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 15

Solution 26:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 16

Solution 27:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 17

Solution 28:
As weather balloon go higher into the atmosphere, the air becomes less dense, so air pressure drops. Because of this, the air that is already inside the balloon  expands to cope with the difference in pressure. The end result is that the balloon expands making it larger.

Solution 29:
Frank ICSE Solutions for Class 9 Chemistry - Study of Gas Laws 18

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Frank ICSE Solutions for Class 9 Chemistry – Elements, Compounds and Mixtures

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Frank ICSE Solutions for Class 9 Chemistry – Elements, Compounds and Mixtures

PAGE NO :41
Solution 1:

  1. Elements: An element is a pure substance which can neither be broken down into simpler substances nor formed from two or more simpler substances by any known physical or chemical process. It is made of only one kind of atoms. It can be divided into four main categories
    1. Metals-Iron, magnesium
    2. Non-metals-Hydrogen, oxygen
    3. Metalloids-Arsenic, antimony
    4. Noble gas-Helium, neon
  2. Compound: A compound is a pure substance that is composed of two or more elements chemically combined in definite proportion by mass.
    The physical and chemical properties of a compound are different from those of its constituent elements.Hydrogen gas is combustible and oxygen is supporter of combustion , their  compound water  which is liquid is neither combustible nor a supporter of combustion.
  3. Mixture: Mixture is a physical combination of two or more substances, whether elements or compounds, which are mixed in any proportion by mass and retain their original properties even after mixing.
    Homogeneous mixture: They have same composition  and the same properties throughout their entire mass. Example- Salt solution, alloys etc.
    Heterogeneous mixture: They have different composition and different properties in different parts of their mass. Example-Mixture of sand and salt, mixture of iron fillings and sulphur etc.

Solution 2:

  1. Oxygen
  2. Carbon, hydrogen, Oxygen
  3. Mercury, Bromine
    1. Helium
    2. Oxygen
  5. Gallium,caesium
  6. Two noble gases are-
  7. Helium
  8. Argon

PAGE NO :42
Solution 3:
Air is a mixture because-

  1. The composition of air is not fixed i.e. the components may be present in any proportion by mass.
  2. Components of air i.e. nitrogen, oxygen etc. do not react with each other.

Solution 4:
Elements – Lead, Mercury, Sodium
Mixtures – Air, petrol, ink, gunpowder
Compounds – Common salt, alcohol, sand

Solution 5:
Pure substance – A pure substance is one which is made up of only one kind of particles. These particles may be atoms or molecules.
Example-Sulphur,  water.
Impure substance – They are mixtures of two or more chemically different substances mixed in indefinite proportions. The constituent substances retain their properties in the mixture.
Example-Mixture of salt and sand, gunpowder

Solution 6:
Mercury is the metal which is liquid at room temperature and bromine is the non-metal which is liquid at room temperature.

Solution 7:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 1

Solution 8:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 2

Solution 9:
Two reasons for believing that copper is a metal and sulphur is a non-metal are:-

  1. Copper is malleable and ductile while sulphur is neither malleable nor ductile.
  2. Copper is a good conductor of heat while sulphur is not good conductor of heat.

Solution 10:
Metalloids – The elements which possess properties intermediate between those of the metals and non-metals are called as metalloids. They react with both acids and alkali’s to form salts.
Ex – Arsenic, antimony

Solution 11:
Graphite is a non-metal which is a good conductor of electricity.

Solution 12:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 3

Solution 13:
Mixture is the general name of the materials which contain atleast two pure substances and show the properties of their constituents.

Solution 14:

  1. Sodium
  2. Bromine
  3. Arsenic
  4. Radon
  5. Mercury
  6. Oxalic acid
  7. Carbon dioxide

Solution 15:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 4

Solution 16:

  1. simpler substances
  2. atomic
  3. same
  4. mixture of salt and water
  5. two

Solution 17:
Names of two other mixtures which contain elements only are-

  1. Bronze
  2. Duralumin

Solution 18:

  1. A Molecule – The smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms.
  2. Atomicity – Atomicity of an element is defined as the number of atoms present in one molecule of that element.

Solution 19:
Since, the constituents of a mixtures may be present in varying proportions so it cannot be expressed by a fixed chemical formula.

Solution 20:

  1. Air
  2. Cement
  3. Milk Sugar solution

Solution 21:
If a mixture of powdered iron and sulphur is heated in a test tube, a black shiny compound iron(II) sulphide (FeS)  is formed.

Solution 22:

  1. Tungsten, Mercury
  2. Graphite, Iodine

PAGE NO :43
Solution 23:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 5

Solution 24:

  1. Chromatography – The chromatography is a technique of separating pure substances from the mixture.
    Advantages of chromatography –

    1. It requires a very small amount of the substance or sample.
    2. The components retain their individuality during the process.
    3. Chromatography finds application in easy separation of substances with similar physical and chemical properties.
  2. Filtration – It is a separation technique for separating a mixture in which one component should be solid and insoluble in the other liquid component.
    Example- Barium sulphate  in water.
  3. Fractional distillation – It is a technique used to separate  two liquids which dissolve in one another.The separation relies on the differences in boiling points of the two liquids.
    No, mixture of chloroform and water cannot be separated by this method.
  4. Centrifugation – It is a method for separating the suspended particles of a substance from a liquid in which the mixture is rotated at a high speed in centrifuge machine.
    Application – The clay particles in water (which are very fine) can be separated by centrifugation.

Solution 25:

  1. The vapour state which is obtained by heating solid without passing through liquid state is called sublimate.
  2. A liquid condensed from vapour in distillation is called distillate.
  3. The liquid produced after filtering a suspension of a solid in a liquid is called filtrate.
  4. Supernatant liquid is the upper layer of fluid found after a mixture has been centrifuged.
  5. If there is a heterogeneous mixture containing an insoluble solid in a liquid, then the solid substance that settle down is called sediment.

Solution 26:
We use fractional distillation to separate alcohol from a mixture of alcohol and water since the difference in boiling point between alcohol and mixture is very less.

Solution 27:

  1. We obtain pure water from sea water by distillation.
  2. A sample of pure iodine and sodium chloride is obtained by sublimation.

Solution 28:
The separation of the mixture depends upon-

  1. Size of the constituents
  2. Magnetic properties of constituents
  3. Mass of the constituents
  4. Solubility of the constituents
  5. Miscibilities of the constituents
  6. Boiling point of the constituents
  7. Diffusion rate of the constituents

Solution 29:
This is a separation technique of solid-solid mixture. This method involves the use of a solvent in which only one of the solid present in the mixture dissolves. Undissolved solid is removed by filtration. Mixture of ammonium chloride and silver chloride is separated by this method.

Solution 30:

  1. By distillation and fractional distillation we separate the mixture of two liquids.
  2. Yes, mixture of chloroform (B.P.= 61 oC) and carbon tetrachloride (B.P.=77 oC) be satisfactorily separated by the process of fractional distillation which is used for separating the various fractions of petroleum.
    For this purpose we will make two fractionating columns in the apparatus.

Solution 31:

  1. Solid-solid mixtures
    1. Magnetic separation method-Separation of iron ore from impurities
    2. Gravity separation-Mixture of saw dust and sand
    3. Solvent extraction-Mixture of sulphur and sand
  2. Solid- liquid mixtures
    1. Evaporation-Water and sodium chloride
    2. Distillation-Iodine in chloroform
    3. Filtration-Barium sulphate in water
  3. Liquid-liquid mixtures
    1. By separating funnel-Oil and water mixture
    2. Distillation-Acetone and water
    3. Fractional distillation-Ethyl alcohol and water

Solution 32:
The chromatography is the technique of separating pure substances from the mixtures. The chromatographic techniques was first employed by a Russian scientist Michael Tswett in 1903 for the separation of coloured substance from the mixture.
Principle of chromatography: The principle of chromatography is based on the difference in the extent of interaction (absorption) of various substances with a stationary phase and a mobile phase. A substance which interacts strongly with the mobile phase goes ahead of the other substance which interacts strongly with the stationary phase.

Solution 33:
Ink generally contain more than one dye. This mixture of ink is used as moving phase. Different constituents of ink move at different speed. The solvent rises up the filter paper over the spot and carries the different coloured components of ink to different heights on the filter paper. Each spot thus obtained at a particular height on the filter paper contains a particular constituent of the ink. Thus, the components of the ink are separated.

Solution 34:
By the help of fractional distillation we separate the components of liquid air.

Solution 35:

  1. Increase in weight – Sulphuric acid and iron
  2. Decrease in weight – Sodium carbonate crystals
  3. No change in weight – Sodium chloride

Solution 36:
By filtration, we will separate a mixture of chalk powder and water.

Solution 37:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 6

Solution 38:
Fractionating column avoid the collection of distillate and re-distillation of distillate several times during fractional distillation.

Solution 39:
Two pair of liquids which can be separated by using a separating funnel-

  1. Oil and water
  2. Chloroform and water

Solution 40:
At first, with the help of magnet, iron nails will separate. Then, by sublimation camphor will separate from common salt.

Solution 41:
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 7
Frank ICSE Solutions for Class 9 Chemistry - Elements, Compounds and Mixtures 8

PAGE NO :44
Solution 42:

  1. When a magnet is moved over ‘X’, iron fillings are pulled away and stick to the magnet. When a magnet is moved over ‘Y’, it remained  unaffected.
  2. When’X’ is treated with carbon disulphide, sulphur dissolves but not iron. While, when’Y’ is treated with carbon disulphide, iron sulphide does not dissolve  but sinks to the bottom of the test tube.
  3. When ‘X’ is treated with dilute HCl, a colourless, odourless gas hydrogen is evolved which burns with a blue flame and is extinguished with a pop sound. While, when ‘Y’ is treated with dilute HCl, a colourless gas with the smell of rotten eggs is evolved which is H2S.
    There is difference in the behavior of ‘X’ and ‘Y’ because ‘X’ is a mixture while ‘Y’ is a compound. The component of a mixture do not react chemically, so retain their identity in the mixture while the components of compound react chemically, so do not retain their identity in the compound.

Solution 43:
Centrifugation is used in milk dairies to separate cream from milk dairies.

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