Class 9 Science Exploring Mixtures and Their Separation MCQs
Class 9 Science Exploring Mixtures and Their Separation MCQs
MCQs
What is the main reason particles in muddy water settle at the bottom after some time? A. They dissolve completely in water B. They are heavier than water and affected by gravity C. They evaporate with water D. They become lighter over time
Which type of mixture is muddy water? A. True solution B. Suspension C. Colloid D. Compound
Why do particles in milk not settle easily when left undisturbed? A. Milk contains colloidal particles B. Milk has no particles C. Milk particles are gases D. Milk is a pure substance
Milk is best classified as: A. Element B. Suspension C. Colloid D. Compound
Which process can occur at temperatures below the boiling point of a liquid? A. Freezing B. Boiling C. Evaporation D. Condensation
During evaporation, molecules escape from: A. The bottom of the liquid B. The entire liquid at once C. The surface of the liquid D. The container walls
Boiling differs from evaporation because boiling: A. Occurs only at the surface B. Takes place at a fixed temperature C. Does not convert liquid into gas D. Happens without heat
Which of the following is a characteristic of boiling? A. Slow process B. Occurs at all temperatures C. Formation of bubbles throughout the liquid D. Occurs only on the surface
Why are rays of sunlight visible through gaps between dense leaves? A. Reflection of light B. Refraction of light C. Scattering of light by tiny particles D. Absorption of light
The visibility of a beam of sunlight in air is an example of: A. Diffusion B. Tyndall effect C. Conduction D. Sublimation
Which of the following is responsible for the scattering of sunlight in air? A. Vacuum B. Dust and fine particles C. Pure water D. Solid rocks
The phenomenon that makes a path of light visible in a dusty room is called: A. Reflection B. Dispersion C. Tyndall effect D. Refraction
Which mixture contains particles large enough to settle on standing? A. Salt solution B. Sugar solution C. Muddy water D. Air
Which statement about evaporation is correct? A. It occurs only at 100°C B. It occurs only when bubbles form C. It can occur at any temperature D. It converts gas into liquid
What helps suspended particles settle in muddy water? A. Friction B. Gravity C. Magnetism D. Pressure
The production of sugar from sugarcane is an example of: A. Chemical reaction B. Separation of mixtures C. Combustion D. Fermentation
Doctors can detect diseases such as malaria using: A. Urine samples only B. A few drops of blood C. Saliva samples only D. X-rays only
Many everyday activities are based on the science of: A. Electricity B. Motion C. Separation of mixtures D. Magnetism
The chapter mainly focuses on: A. Forces and motion B. Properties and separation of mixtures C. Human anatomy D. Weather and climate
Which of the following is mentioned as an industrial process involving separation? A. Iron extraction B. Sugar production C. Paper making D. Road construction
The separation of mixtures is important because it: A. Has no practical use B. Plays a crucial role in daily life C. Is used only in laboratories D. Is limited to agriculture
Medical tests for diseases like malaria depend on: A. Separation techniques B. Sound waves C. Nuclear energy D. Magnetic fields
Which property of mixtures will be explored further in the chapter? A. Colour only B. Behaviour and properties C. Shape only D. Mass only
The science of separating mixtures helps in: A. Industrial applications B. Medical diagnosis C. Everyday activities D. All of the above
Sugar crystals obtained from sugarcane are: A. Liquid B. Gas C. Solid D. Plasma
The chapter encourages students to: A. Ignore practical applications B. Explore mixtures in greater depth C. Study only pure substances D. Focus only on theory
Which of the following is NOT mentioned in the passage? A. Sugar production B. Malaria detection C. Separation of mixtures D. Electricity generation
The word “fascinating” in the passage refers to: A. Boring B. Unimportant C. Interesting and engaging D. Dangerous
Separation techniques are useful in: A. Industries only B. Hospitals only C. Both industries and healthcare D. Neither industries nor healthcare
The main theme of the passage is: A. Sources of energy B. Importance and applications of separating mixtures C. Structure of atoms D. Classification of plants
A mixture that has the same composition throughout is called: A. Suspension B. Heterogeneous mixture C. Homogeneous mixture D. Colloid
A well-stirred sugar solution is considered homogeneous because: A. Sugar settles at the bottom B. It tastes equally sweet throughout C. Water evaporates quickly D. Sugar particles are visible
Which of the following is an example of a homogeneous mixture? A. Sand and water B. Oil and water C. Vinegar D. Chalk powder and water
Vinegar is a mixture of: A. Carbon dioxide and water B. Acetic acid and water C. Salt and water D. Oil and water
Soda is a homogeneous mixture of: A. Oxygen and water B. Nitrogen and water C. Carbon dioxide and water D. Hydrogen and water
Which of the following is a heterogeneous mixture? A. Sugar solution B. Vinegar C. Soda D. Sand and water
In a sand-water mixture, sand particles: A. Dissolve completely B. Remain invisible C. Settle with time D. Turn into gas
Which characteristic is common to all homogeneous mixtures? A. Visible particles B. Uniform composition C. Settling of particles D. Separation by filtration
Oil and water together form: A. A homogeneous mixture B. A heterogeneous mixture C. A pure substance D. A compound
In Activity 5.1, Group A prepared a mixture using: A. Chalk powder and water B. Milk and water C. Salt and water D. Sand and water
Group B prepared a mixture of: A. Salt and water B. Chalk powder and water C. Milk and water D. Oil and water
Group C prepared a mixture using: A. Salt and water B. Chalk powder and water C. Milk and water D. Sand and water
Which instrument is used to direct a beam of light through the mixtures? A. Torch B. Microscope C. Laser pointer D. Telescope
While observing the laser beam, students should: A. Look directly into the beam B. Wear sunglasses only C. Avoid looking directly into the beam D. Touch the laser source
Looking directly into a laser beam may cause: A. Headache B. Temporary blindness only C. Irreversible eye damage D. Hearing loss
The purpose of leaving the mixtures undisturbed is to observe: A. Colour changes B. Settling of particles C. Temperature changes D. Evaporation only
Filtration is used in the activity to determine: A. The boiling point of the mixture B. Whether residue remains on the filter paper C. The density of water D. The colour of the solution
Which mixture is most likely to leave a noticeable residue on filter paper? A. Salt and water B. Pure water C. Chalk powder and water D. Soda water
A solution always remains: A. Heterogeneous B. Visible to the naked eye C. Homogeneous D. Unstable
The main objective of Activity 5.1 is to: A. Compare different types of mixtures B. Measure the speed of light C. Study plant growth D. Determine water purity
Which property helps classify mixtures as homogeneous or heterogeneous? A. Taste only B. Colour only C. Uniformity of composition D. Weight only
In a homogeneous mixture, the components: A. Can be easily distinguished B. Are uniformly distributed C. Always settle down D. Form layers
Which of the following pairs represents a homogeneous mixture? A. Sand and water B. Oil and water C. Sugar and water D. Chalk powder and water
A heterogeneous mixture generally has: A. Uniform composition B. No visible particles C. Non-uniform composition D. Only one component
The activity concludes that the prepared mixtures are: A. Identical in all respects B. Different types of mixtures C. Pure substances D. Chemical compounds
A solution is best defined as: A. A heterogeneous mixture B. A homogeneous mixture C. A pure substance D. A compound
In a solution, the substance that gets dissolved is called: A. Solvent B. Solute C. Mixture D. Suspension
In a sugar-water solution, sugar acts as: A. Solvent B. Solute C. Catalyst D. Product
The substance that dissolves the solute is called: A. Solvent B. Solute C. Residue D. Precipitate
In sugar solution, water is the: A. Solute B. Solvent C. Compound D. Gas
The concentration of a solution refers to: A. Colour of solution B. Amount of solute in a given amount of solution or solvent C. Temperature of solution D. Volume of container
ORS (Oral Rehydration Solution) requires: A. Random mixing of salt and sugar B. Fixed proportions of salt, sugar and water C. Only sugar in water D. Only salt in water
Changing the amount of solute in ORS preparation will: A. Always improve its effect B. Not affect the solution C. Change its effectiveness D. Turn it into a pure substance
Farmers must carefully control pesticide concentration because: A. It improves water taste B. Wrong concentration can harm crops and environment C. It increases rainfall D. It changes soil colour only
Too little pesticide results in: A. Better crop protection B. No effect on crops C. Poor protection of crops D. Soil improvement
The concentration of a solution is expressed as: A. Weight of container B. Amount of solute in a given amount of solution C. Colour intensity D. Volume of solvent only
Which of the following is NOT a method of expressing concentration? A. Mass by mass percentage B. Mass by volume percentage C. Volume by volume percentage D. Temperature percentage
Mass by mass percentage is written as: A. % m/v B. % v/v C. % m/m D. % t/t
% m/m is commonly used for: A. Gases only B. Homogeneous mixtures C. Pure metals only D. Only water solutions
In % m/m, concentration is expressed in: A. Grams per 100 g of solution B. Litres per 100 L C. Degrees Celsius D. Moles per litre
Mass by volume percentage is used when: A. Both substances are gases B. Volume measurement is easier than mass C. Only solids are present D. No measurement is needed
% m/v expresses: A. Volume of solute in 100 mL solution B. Mass of solute in 100 mL solution C. Mass of solvent only D. Temperature change
A common example of % m/v solution is: A. Salt solution B. 5% glucose solution C. Sand and water D. Air mixture
Volume by volume percentage is used for: A. Solid mixtures B. Two miscible liquids C. Metals D. Gases only
% v/v expresses: A. Mass of solute in 100 g solution B. Volume of solute in 100 mL solution C. Temperature change D. Density only
Vinegar is an example of: A. % m/m mixture B. % v/v mixture C. Suspension D. Pure substance
Perfumes are commonly expressed in: A. % m/m B. % v/v C. % m/v D. None of these
ORS must be prepared carefully because: A. It is only for taste B. It is a medical solution C. It is a gas mixture D. It is a solid
The concentration concept is important in: A. Only laboratories B. Medicine, agriculture, food and daily life C. Only schools D. Only industries
A solution always contains: A. Only solute B. Only solvent C. Solute and solvent D. Only gases
A saline drip used in hospitals mainly contains: A. Sugar in water B. Sodium chloride in water C. Calcium carbonate in water D. Oxygen in water
The concentration of hospital saline solution is: A. 0.5% m/v B. 0.7% m/v C. 0.9% m/v D. 9% m/v
In 0.9% saline solution, the unit m/v stands for: A. Mass by volume B. Mass by velocity C. Mole by volume D. Mass by volume ratio of gas
0.9% m/v saline solution means: A. 0.9 g salt in 10 mL solution B. 0.9 g salt in 100 mL solution C. 9 g salt in 100 mL solution D. 90 g salt in 100 mL solution
The main purpose of saline drip in hospitals is to: A. Increase body temperature B. Replace lost body fluids C. Increase blood sugar D. Cure infections directly
Sodium chloride is commonly known as: A. Baking soda B. Washing soda C. Common salt D. Lime powder
The saline solution used in hospitals is safe for: A. Plants B. Blood C. Metals D. Air
Saline solution helps the body by: A. Removing bones B. Replacing lost fluids C. Producing oxygen D. Increasing body weight instantly
The correct concentration unit used in saline solution is: A. % m/m B. % v/v C. % m/v D. % w/w only
In a 0.9% saline solution, the amount of salt is measured in: A. Litres B. Kilograms C. Grams D. Millilitres
The total volume of saline solution mentioned is: A. 10 mL B. 50 mL C. 100 mL D. 1000 mL
Saline drip is commonly used in: A. Agriculture B. Hospitals C. Industries only D. Cooking
The concentration 0.9% m/v means salt is: A. Completely absent B. Present in small controlled amount C. More than water D. Undissolved
If saline concentration is too high, it may: A. Improve health faster B. Harm body balance C. Increase oxygen level D. Become pure water
The key idea of saline solution is: A. Random mixing of salt and water B. Controlled concentration for medical use C. Pure salt solution D. Gas mixture in blood
The maximum amount of solute that can dissolve in a fixed amount of solvent at a given temperature is called: A. Concentration B. Solubility C. Density D. Evaporation
Solubility is usually expressed in: A. g per 100 g of solvent B. kg per litre of gas C. mL per second D. degree Celsius
A solution that cannot dissolve any more solute at a given temperature is called: A. Dilute solution B. Unsaturated solution C. Saturated solution D. Colloid
Solubility of a solid in a liquid generally increases with: A. Decrease in temperature B. Increase in temperature C. No change in temperature D. Pressure only
Solubility of gases in liquids generally: A. Increases with temperature B. Decreases with temperature C. Remains constant D. Becomes zero always
Solubility depends on: A. Colour of solution B. Temperature C. Shape of container D. Volume of glass only
A solubility curve represents the relation between: A. Time and temperature B. Solubility and temperature C. Mass and volume D. Pressure and time
In a solubility graph, the x-axis represents: A. Solubility B. Temperature C. Mass D. Volume
In a solubility graph, the y-axis represents: A. Temperature B. Pressure C. Solubility D. Time
The unit of solubility used in the graph is: A. g per 100 g of water B. kg per litre C. mL per minute D. mol per second
If a substance shows increasing solubility with temperature, it is most likely: A. A solid solute B. A gas solute C. A vacuum D. A pure liquid
A decrease in solubility of gases with temperature explains why: A. Hot drinks taste sweeter B. Warm soda loses gas faster C. Ice melts slowly D. Salt dissolves faster
Which of the following is an example of a saturated solution? A. No solute dissolved B. Maximum solute dissolved at given temperature C. Infinite solute dissolved D. No solvent present
Solubility is important because it helps in: A. Colouring mixtures B. Separating substances from mixtures C. Increasing pressure D. Changing shape of substances
In the solubility curve, compound ‘A’ and ‘B’ represent: A. Gases only B. Solutes with different solubility behavior C. Solvents D. Pure water samples
If temperature increases, the solubility of compound ‘A’ in water generally: A. Decreases B. Increases C. Becomes zero D. Becomes constant
If a solution is saturated, adding more solute will: A. Increase solubility B. Dissolve immediately C. Not dissolve D. Turn into gas
The relationship between solubility and temperature is shown using: A. Bar graph B. Pie chart C. Line graph D. Circle diagram
Which statement is correct about gases in liquids? A. Solubility increases with temperature B. Solubility decreases with temperature C. Solubility does not change D. Gases do not dissolve
The study of solubility helps in understanding: A. Only physical changes B. Behaviour of mixtures C. Only chemical reactions D. Only metals
Crystallization is a process used to: A. Melt solids into liquids B. Form crystals from a solution C. Convert gas into solid directly D. Separate gases from air
A crystal is defined as a solid with: A. Random arrangement of particles B. No fixed structure C. Regular geometric arrangement of particles D. Liquid-like behavior
Crystallization is mainly used to: A. Increase solubility B. Purify solids C. Evaporate liquids D. Mix solutions
The principle of crystallization is based on: A. Colour differences B. Magnetic properties C. Differences in solubility at different temperatures D. Density of gases
When a saturated solution of a substance is cooled, excess solute: A. Evaporates B. Freezes into gas C. Separates as crystals D. Dissolves completely
A saturated solution is one in which: A. No solute is present B. Maximum solute is dissolved at a given temperature C. Solute is not dissolved at all D. Solvent is absent
Crystals of substances like rock salt and sugar are examples of: A. Artificial compounds only B. Natural crystalline forms C. Gases solidified D. Pure liquids
Snowflakes are crystals formed when: A. Water boils B. Water vapour freezes in air C. Ice melts D. Salt dissolves
Frost on windows is formed due to: A. Evaporation of glass B. Freezing of water vapour into ice crystals C. Melting of ice D. Dissolution of gases
In laboratories, crystallization is used for: A. Mixing solutions B. Separating pure solids from mixtures C. Increasing temperature D. Changing gas pressure
Crystallization is especially useful when: A. Both solids are insoluble B. One component is present in small quantity C. Only gases are present D. No solvent is used
Impurities in a hot saturated solution are removed by: A. Filtration B. Condensation C. Magnetism D. Freezing
Slow cooling of a saturated solution results in: A. Smaller crystals B. No crystals C. Larger and well-formed crystals D. Gas formation
Rapid cooling of a saturated solution usually produces: A. Large crystals B. Small and less well-formed crystals C. No change D. Pure solvent only
Copper sulfate crystals are typically: A. Green and soft B. Blue and well-shaped C. White and gaseous D. Colourless liquid
Sulfuric acid is sometimes added during crystallization to: A. Increase evaporation rate B. Prevent unwanted reactions and improve purity C. Change colour of crystals D. Increase boiling point
Crystallization helps in: A. Breaking compounds into atoms B. Purifying substances C. Burning mixtures D. Increasing density of liquids
Salt from seawater is obtained mainly by: A. Distillation B. Evaporation and crystallization C. Filtration only D. Condensation
Natural crystals can be found in: A. Only laboratories B. Mines and caves C. Only oceans D. Only rivers
Quartz is an example of: A. Artificial plastic B. Natural crystal C. Gas mixture D. Liquid solution
If a saturated solution is left undisturbed and slowly cooled, it will: A. Form crystals B. Turn into gas C. Become unsaturated instantly D. Lose all solute
Crystallization is preferred over evaporation when: A. Solvent must also be recovered B. Only gas is present C. No solid is involved D. Temperature is constant only
Acetone and water are separated using: A. Filtration B. Crystallization C. Distillation D. Sieving
The size of crystals depends mainly on: A. Colour of solution B. Rate of cooling C. Shape of container D. Sound vibrations
The main aim of crystallization is to obtain: A. Impure solids B. Pure crystalline substances C. Gases only D. Liquid mixtures
Crystallization of salt in India was traditionally practiced by: A. Farmers in deserts B. Coastal communities C. Mountain tribes D. Forest dwellers
Panga salt was obtained by: A. Freezing seawater B. Boiling concentrated sea brine C. Filtering river water D. Condensing steam
Karkatch salt was produced by: A. Evaporation of seawater B. Mixing salt with sand C. Boiling fresh water D. Crushing rocks
The process used in traditional salt production is mainly: A. Filtration B. Crystallization C. Sublimation D. Distillation
Sea brine refers to: A. Freshwater from rivers B. Concentrated saltwater C. Pure distilled water D. Rainwater
Salt crystals formed by traditional methods differ mainly in: A. Colour only B. Size C. Shape of container D. Temperature of air only
Coastal communities in India used natural processes to: A. Extract metals B. Produce salt C. Make plastics D. Generate electricity
Evaporation of seawater leads to: A. Formation of ice B. Formation of salt crystals C. Formation of gases only D. Dissolution of salt
Boiling concentrated brine helps in: A. Diluting salt B. Obtaining salt crystals C. Removing oxygen D. Producing sugar
The ancient salt-making methods in India show: A. Lack of scientific knowledge B. Early use of separation techniques C. Only modern technology usage D. No use of chemistry
Salt obtained from sea water is an example of: A. Artificial compound B. Naturally derived crystalline substance C. Gas mixture D. Metal alloy
Which of the following is TRUE about traditional salt production? A. Only one type of salt was produced B. Salt crystals of different sizes were formed C. No evaporation was involved D. No heating was used
The main principle involved in salt formation is: A. Magnetism B. Crystallization C. Combustion D. Fermentation
Sea brine becomes concentrated when: A. Water is added B. Water evaporates C. Salt melts D. Air is removed
The passage highlights India’s contribution in: A. Space science only B. Traditional chemical separation techniques C. Electrical engineering D. Nuclear physic
Distillation is used to separate: A. Two solids B. A gas and a solid C. Miscible liquids or liquid from dissolved solids D. Two immiscible liquids
In distillation, separation is based on: A. Colour difference B. Boiling point difference C. Density difference only D. Magnetism
The liquid with lower boiling point in a mixture: A. Remains unchanged B. Vapourises first C. Freezes first D. Does not evaporate
The vapour formed during distillation is converted back into liquid by: A. Heating B. Filtration C. Cooling D. Sublimation
The device used to cool vapours in distillation is called: A. Burner B. Thermometer C. Condenser D. Beaker
Distillation is useful when the difference in boiling points is: A. Less than 5°C B. About 25°C or more C. Exactly 0°C D. Negative
The pure liquid obtained after condensation is called: A. Residue B. Distillate C. Filtrate D. Precipitate
In a distillation flask, the remaining substance after evaporation is: A. Gas B. Residue C. Vapour D. Distillate
Acetone boils at approximately: A. 0°C B. 56°C C. 100°C D. 150°C
Water boils at: A. 56°C B. 90°C C. 100°C D. 120°C
Acetone and water can be separated by distillation because: A. They are immiscible B. They have similar boiling points C. Their boiling points differ significantly D. They are solids
The condenser in a distillation setup is used for: A. Heating liquid B. Cooling vapour into liquid C. Measuring temperature D. Mixing liquids
The thermometer in distillation measures: A. Pressure B. Colour change C. Temperature of vapour D. Volume of liquid
Distillation can also separate: A. Two solids B. A liquid from dissolved solids C. Two gases only D. Two metals
The liquid collected after condensation is called: A. Residue B. Distillate C. Solute D. Solvent
Fractional distillation is used when boiling point difference is: A. Very large B. Very small (less than 25°C) C. Zero D. Infinite
Petroleum products are separated using: A. Filtration B. Fractional distillation C. Crystallization D. Evaporation only
Crude oil is: A. A pure substance B. A single gas C. A mixture of useful hydrocarbons D. A solid mineral
LPG is obtained from: A. Solid rock B. Gaseous fraction of petroleum C. Sea water D. Wood
Fractional distillation separates substances based on: A. Colour differences B. Large boiling point differences only C. Small differences in boiling points D. Solubility in water
Distillation requires both: A. Heating and cooling B. Freezing and melting C. Filtration and sedimentation D. Mixing and stirring
The part of distillation setup where mixture is heated is: A. Condenser B. Distillation flask C. Thermometer bulb D. Beaker
Vapours in distillation travel from: A. Cold to hot region B. Distillation flask to condenser C. Condenser to burner D. Thermometer to flask
One major application of distillation in India is: A. Metal extraction B. Perfume making (Mitti ka Ittar) C. Plastic manufacturing D. Cement production
Deg-Bhapka method is related to: A. Crystallization B. Traditional distillation C. Filtration D. Evaporation only
The word “chromatography” is derived from: A. Latin words only B. Greek words C. Sanskrit words D. Arabic words
In Greek, “chroma” means: A. Write B. Colour C. Light D. Mixture
The Greek word “graphein” means: A. To mix B. To write C. To separate D. To heat
Chromatography literally means: A. Writing with ink B. Writing with colour C. Mixing colours D. Separating gases
Chromatography was first used to separate: A. Metals B. Coloured substances like dyes and inks C. Water and oil D. Solids and gases
The main idea behind chromatography is: A. Heating substances B. Writing with chemicals C. Separation of coloured components D. Freezing mixtures
Which of the following is an example of substances first separated using chromatography? A. Sand and water B. Dyes and inks C. Salt and sugar D. Oil and petrol
Chromatography is mainly used for: A. Mixing solutions B. Separating components of mixtures C. Increasing solubility D. Heating liquids
The origin of chromatography is: A. Chemical reaction theory B. Colour separation studies C. Atomic theory D. Electrical conduction
Chromatography helps in separating substances based on: A. Colour only B. Movement of components through a medium C. Density of solids only D. Boiling point only
The term “chroma” is related to: A. Sound B. Colour C. Temperature D. Mass
The word “graphein” is related to: A. Writing B. Mixing C. Heating D. Cooling
Chromatography was initially used for: A. Metals extraction B. Ink and dye separation C. Gas production D. Water purification
The main purpose of chromatography is: A. To destroy mixtures B. To analyse and separate components C. To increase pressure D. To melt solids
Chromatography belongs to the study of: A. Electricity B. Separation techniques C. Heat transfer D. Motion of planets
Paper chromatography is mainly used to: A. Mix substances B. Separate components of a mixture C. Increase solubility D. Heat solutions
In the experiment, the ink spot is placed on: A. The top of the paper B. The middle of the paper C. A pencil line on the paper strip D. The bottom of the container
The pencil line in chromatography is used because: A. Pencil dissolves in water B. Ink dissolves in water C. Pencil does not dissolve in water D. It reacts with solvent
In paper chromatography, the solvent level should be: A. Above the ink spot B. Below the ink spot C. Equal to ink spot D. Not required
As water rises in paper chromatography, it: A. Stops movement of ink B. Carries ink components upward C. Burns the paper D. Converts ink into gas
Different colours appear in black ink because: A. Ink is pure B. Ink contains only one pigment C. Ink contains multiple pigments D. Water changes colour
Paper chromatography works on the principle of: A. Magnetism B. Differences in movement of components in solvent C. Freezing points D. Density of solids
Which of the following can be used as a solvent in chromatography? A. Only water B. Only oil C. Water or alcohol depending on substance D. Only gases
Green pigments in leaves can be separated using: A. Filtration B. Paper chromatography C. Sieving D. Distillation
The movement of substances in chromatography depends on: A. Colour only B. Speed of movement in solvent C. Size of container only D. Temperature only
Paper chromatography is mainly used to: A. Mix substances B. Separate components of a mixture C. Increase solubility D. Heat solutions
In the experiment, the ink spot is placed on: A. The top of the paper B. The middle of the paper C. A pencil line on the paper strip D. The bottom of the container
The pencil line in chromatography is used because: A. Pencil dissolves in water B. Ink dissolves in water C. Pencil does not dissolve in water D. It reacts with solvent
In paper chromatography, the solvent level should be: A. Above the ink spot B. Below the ink spot C. Equal to ink spot D. Not required
As water rises in paper chromatography, it: A. Stops movement of ink B. Carries ink components upward C. Burns the paper D. Converts ink into gas
Different colours appear in black ink because: A. Ink is pure B. Ink contains only one pigment C. Ink contains multiple pigments D. Water changes colour
Paper chromatography works on the principle of: A. Magnetism B. Differences in movement of components in solvent C. Freezing points D. Density of solids
Which of the following can be used as a solvent in chromatography? A. Only water B. Only oil C. Water or alcohol depending on substance D. Only gases
Green pigments in leaves can be separated using: A. Filtration B. Paper chromatography C. Sieving D. Distillation
The movement of substances in chromatography depends on: A. Colour only B. Speed of movement in solvent C. Size of container only D. Temperature only
Oil and water form: A. Homogeneous mixture B. Compound C. Immiscible liquids D. Solution
Immiscible liquids are those that: A. Mix completely B. Do not mix and form layers C. Form gases D. Dissolve solids
Oil and water can be separated using: A. Filtration B. Separating funnel C. Evaporation D. Sieving
In a separating funnel, oil forms the: A. Lower layer B. Upper layer C. Gas layer D. Solid layer
Water is collected first in a separating funnel because it: A. Is lighter than oil B. Forms lower layer C. Evaporates quickly D. Turns into gas
Which of the following is NOT a heterogeneous mixture? A. Sand and water B. Oil and water C. Sugar solution D. Smoke
Smoke is an example of: A. Homogeneous mixture B. Solid-gas heterogeneous mixture C. Pure gas D. Pure liquid
Fog is an example of: A. Solid in gas B. Liquid droplets in gas C. Solid in liquid D. Pure gas
Most gas mixtures are: A. Heterogeneous B. Homogeneous C. Solid mixtures D. Unstable
Hydrogen and oxygen mixture used in rockets is: A. Solid mixture B. Heterogeneous mixture C. Homogeneous gas mixture D. Liquid mixture
Iron nails can be separated from sawdust using: A. Water B. Magnet C. Heat D. Filtration
A separating funnel works on the principle of: A. Magnetic separation B. Density difference C. Evaporation D. Sublimation
In chromatography, components separate because they: A. Have same speed B. Move at different speeds C. Do not dissolve D. Are all gases
Ink separation into colours shows that ink is: A. Pure substance B. Mixture of pigments C. Element D. Compound
The main purpose of paper chromatography is: A. Heating liquids B. Identifying components in a mixture C. Freezing mixtures D. Increasing mass
Sublimation is the process in which a substance changes directly from: A. Solid to liquid B. Liquid to gas C. Solid to gas D. Gas to liquid
In the camphor-sand experiment, camphor is separated from sand because camphor: A. Dissolves in water B. Sublimes on heating C. Reacts with sand D. Does not heat up
Sand remains in the china dish because it: A. Melts on heating B. Sublimes C. Does not sublime D. Evaporates
The solid deposit formed on the inner wall of the funnel is: A. Sand B. Water C. Camphor D. Salt
The reverse process of sublimation is called: A. Evaporation B. Deposition C. Condensation D. Melting
Sublimation occurs when a substance: A. Melts first then evaporates B. Changes directly from solid to vapour C. Changes from liquid to solid D. Dissolves in water
Which of the following is a sublimable substance? A. Salt B. Sugar C. Naphthalene D. Sand
Dry ice is the solid form of: A. Oxygen B. Carbon dioxide C. Nitrogen D. Methane
Dry ice undergoes: A. Melting B. Sublimation C. Freezing D. Filtration
Sublimation is useful for separating mixtures when: A. Both substances melt B. One component sublimes and the other does not C. Both are liquids D. Both are gases
An alloy is a: A. Pure element B. Homogeneous mixture of metals (or metal + non-metal) C. Heterogeneous mixture D. Gas mixture
Metals generally dissolve into each other at: A. Room temperature B. High temperature when molten C. Very low temperature D. Only in water
Alloys are formed by: A. Freezing gases B. Mixing molten metals and cooling C. Crushing solids D. Evaporating liquids
Physical methods cannot separate components of: A. Solutions B. Mixtures of sand and salt C. Alloys D. Suspensions
The main purpose of making alloys is to: A. Make substances weaker B. Improve properties like strength and corrosion resistance C. Reduce melting point to zero D. Separate metals easily
Brass is an alloy of: A. Iron and carbon B. Copper and zinc C. Copper and tin D. Iron and nickel
Bronze is mainly composed of: A. Copper and zinc B. Copper and tin C. Iron and carbon D. Nickel and chromium
Stainless steel contains mainly: A. Copper and zinc B. Iron with chromium, nickel and carbon C. Aluminium and magnesium D. Gold and silver
Chromium in stainless steel helps in: A. Making it soft B. Increasing corrosion resistance C. Making it liquid D. Increasing solubility
Nickel in stainless steel mainly improves: A. Colour only B. Strength and durability C. Taste D. Solubility
Molybdenum in alloys helps in: A. Increasing corrosion resistance B. Making alloys gaseous C. Reducing mass to zero D. Separating components easily
Brass contains approximately: A. 50% copper and 50% zinc B. 80% copper and 20% zinc C. 20% copper and 80% zinc D. Only copper
Bronze contains approximately: A. 80% copper and 20% tin B. 50% copper and 50% tin C. Only tin D. Only iron
Camphor can be separated from sand using: A. Filtration B. Sublimation C. Distillation D. Sieving
A key property of alloys is that they are: A. Easily separated by filtration B. Pure substances C. Difficult to separate by physical methods D. Always liquids
A suspension is a mixture in which solid particles: A. Completely dissolve in liquid B. Remain suspended in the medium C. Turn into gas D. Form a true solution
In a suspension, particles are: A. Invisible under microscope B. Visible to naked eye C. Always gaseous D. Always dissolved
An example of a suspension is: A. Sugar solution B. Salt solution C. Sand in water D. Air
Particles in a suspension are: A. Smaller than solution particles B. Equal to gas molecules C. Larger than solution particles D. Not present
Muddy water is an example of: A. True solution B. Suspension C. Gas mixture D. Pure liquid
Mud particles in water settle at the bottom due to: A. Magnetism B. Gravity C. Evaporation D. Boiling
Filtration is sometimes insufficient to remove: A. Large stones B. Very fine suspended particles C. Metals D. Gases
When muddy water is left undisturbed, it becomes: A. Completely clear instantly B. Less cloudy over time C. Solid ice D. Gas mixture
Centrifugation works on the principle of: A. Magnetic separation B. Centrifugal force C. Evaporation D. Filtration
In centrifugation, heavier particles: A. Move upward B. Move outward and settle down C. Dissolve in liquid D. Float at top
Lighter liquid in centrifugation: A. Settles at bottom B. Remains at top C. Evaporates D. Solidifies
Centrifugation is used to separate: A. Sugar and salt B. Blood components C. Oil and gas D. Metals
The centrifuge tube becomes: A. Vertical always B. Horizontal during spinning C. Filled with gas D. Heated strongly
Paperfuge is a: A. Chemical reagent B. Hand-powered centrifuge device C. Heating machine D. Filter paper type
Paperfuge is useful in: A. Agriculture only B. Medical testing in remote areas C. Cooking D. Metal extraction
Coagulation is the process in which fine particles: A. Evaporate B. Clump together C. Dissolve completely D. Turn into gas
Alum acts as a: A. Solvent B. Coagulant C. Fuel D. Catalyst only
After coagulation, particles: A. Become invisible B. Form larger clumps C. Dissolve fully D. Turn into solution
Settling of clumped particles is called: A. Sublimation B. Sedimentation C. Distillation D. Filtration
Coagulated particles are separated by: A. Decantation or filtration B. Evaporation only C. Heating only D. Magnetic force
Formation of paneer involves: A. Filtration B. Coagulation C. Sublimation D. Centrifugation
Blood is classified as a: A. True solution B. Suspension C. Colloid D. Pure substance
Colloidal particles are generally sized between: A. Less than 1 nm B. 1–1000 nm C. More than 1000 nm D. Exactly 0 nm
In a colloid, particles: A. Settle quickly B. Do not settle C. Form crystals D. Evaporate
Milk is an example of: A. Solution B. Suspension C. Colloid D. Gas mixture
Tomato sauce is a: A. Pure liquid B. Colloid C. Gas D. Element
Colloids are different from suspensions because they: A. Have larger particles B. Do not settle on standing C. Always dissolve D. Are gases
Blood components can be separated by: A. Sieving B. Centrifugation C. Sublimation D. Filtration only
Red blood cells, plasma, and platelets are separated in: A. Cooking pot B. Blood bank centrifugation C. Filter paper D. Beaker evaporation
Compared to solutions, colloidal particles are: A. Smaller B. Larger but not visible C. Same size D. Not present
The scattering of light by particles in a mixture is called: A. Reflection B. Refraction C. Tyndall effect D. Diffusion
The Tyndall effect is first explained by: A. Isaac Newton B. John Tyndall C. Dalton D. Rutherford
The Tyndall effect is observed in: A. True solutions only B. Colloids and suspensions C. Pure water only D. Pure gases only
A solution does NOT show Tyndall effect because: A. It is coloured B. Particles are very large C. Particles are too small to scatter light D. It contains gas
The path of light becomes visible in: A. Solutions B. Colloids C. Pure water only D. Metals only
Scattering of light is commonly observed in: A. Dark room with dust particles B. Boiling water C. Freezing ice D. Melting metal
Floodlights in stadiums appear bright due to: A. Heating effect B. Tyndall effect C. Magnetic effect D. Evaporation
Colloidal particles are sized between: A. Less than 1 nm B. 1–1000 nm C. More than 1000 nm D. Exactly 0 nm
In a colloid, particles: A. Settle quickly B. Do not settle C. Are always gases D. Are always solids
The two components of a colloid are: A. Solute and solvent B. Acid and base C. Dispersed phase and dispersion medium D. Solid and gas
The dispersed phase in milk is: A. Water B. Fat droplets C. Sugar D. Salt
Milk is an example of: A. True solution B. Suspension C. Colloid D. Gas mixture
Emulsions are colloids where: A. Solid in gas B. Gas in solid C. Liquid in liquid D. Solid in solid
Butter is an example of: A. Oil-in-water emulsion B. Water-in-oil emulsion C. Gas mixture D. True solution
Emulsifying agents help to: A. Break mixtures permanently B. Stabilize emulsions C. Evaporate liquids D. Increase boiling point
Clouds are best classified as: A. True solution B. Suspension C. Colloid D. Pure gas
Hazy air in cities is due to: A. Pure oxygen B. Scattering of light by dust and smoke C. Boiling water D. Magnetic fields
Sewage treatment involves: A. Only filtration B. Sedimentation, coagulation and filtration C. Only evaporation D. Only melting
Alum is used in water purification as a: A. Solvent B. Coagulant C. Fuel D. Catalyst only
In coagulation, fine particles: A. Dissolve completely B. Clump together and settle C. Turn into gas D. Become invisible permanently
The main difference between solution and colloid is: A. Colour only B. Particle size and light scattering C. Shape of container D. Temperature only
True solutions have particle size: A. More than 1000 nm B. 1–1000 nm C. Less than 1 nm D. Exactly 10 nm
Suspensions differ from colloids because suspensions: A. Never scatter light B. Settle on standing C. Are always transparent D. Cannot be filtered
Blood is best classified as: A. Solution B. Suspension C. Colloid D. Element
Red blood cells in blood represent: A. Dispersion medium B. Dispersed phase C. Solvent D. Catalyst
A key property of colloids is: A. Rapid settling B. No settling and light scattering C. Always transparent D. Always gaseous
In paper chromatography, separation occurs due to: A. Boiling point difference B. Movement speed differences of components C. Density only D. Magnetism
Mixtures like sand and water are: A. Solutions B. Colloids C. Suspensions D. Elements
Filtering muddy water alone may not work because: A. Water evaporates B. Fine particles pass through filter C. Sand dissolves D. Salt forms
The Tyndall effect helps to identify: A. Pure metals B. Colloids C. Gases only D. Crystals