Define sublimation. Which type of mixtures are separated by this technique ?
A teacher told three students A, B and C to prepare 25% solution (mass by volume) of KOH.
Student A dissolved 25g of KOH in 100g of water, student B dissolved 25g of KOH in 100 ml
of water and student C dissolved 25g KOH in water and made the volume 100 ml. Which one
of them has made required 25% solution ? Give your answer with reason.
The room temperature is 25C. What is the corresponding temperature on the Kelvin
scale ?
The room temperature is 25C. What is the corresponding temperature on the Kelvin
scale ?
Define sublimation. Give two examples of substances that sublime. Mention a situation from
your daily life where you observe this process.
Differentiate between an element and a compound. Categorize the following substances into
elements and compounds- sodium chloride, Iodine, water, 24 carat gold, Oxygen gas, Carbon.
Name any two processes which illustrate that on heating movement of particles of
matter increases.
Define fluidity. Explain why do liquids flow ?
State the principle involved in the following techniques of separation of mixtures :
(a) Chromatography
(b) Fractional distillation
How will you separate a mixture of common salt, camphor and Iron filings. Describe the
process
By taking into account the three states of the matter comment on the following :
(a) rigidity (b) compressibility (c) fluidity
Under what conditions gases can be liquefied ? In which form LPG is filled in gas cylinder ?
Write your observations when the following processes take place
(a) an aqueous solution of sugar is heated till it gets dried up.
(b) a saturated solution of potassium chloride prepared at 60C is allowed to cool at room
temperature.
(c) a mixture of iron filings and sulphur powder is heated strongly.
(d) A beam of light is passed through a colloidal solution.
(e) dil – HCl is added to the mixture of iron filings and sulphur powder.
State any three characteristics of the particles of matter?
Which of the following are matter?
table, oxygen, affection, milk, cold, thirst, salt.
Among solids, liquids and gases, which one has :
(a) maximum force of attraction between the particles
(b) minimum spaces in between particles.
Give reason in support of your answer.
(a) Both smoke and fog are aerosols. In what way they are different ?
(b) How do sol and gel differ from each other ? Give one example of each.
Demonstrate by an activity that the rate of intermixing depends upon the forces of attraction
between the particles of matter.
Define an element. Classify the elements into three categories on the basis of their properties.
Identify the physical and chemical changes from the following :
(a) Heating the mixture of iron filings and sulphur.
(b) Ripening of fruits
(c) Dissolution of salt in water
(d) Rusting of iron-chair.
(e) Making egg omelets
Name and explain all the processes involved when heat is supplied to a solid and vice-versa
What are Aerosols ? Give any two examples.
(a) Name a technique to separate a mixture of two or more miscible liquids for which
difference in boiling points is less than 25 K.
(b) Describe the structure of the column used in the above technique. Why is it used ?
What do you observe when ice cubes are put in a beaker containing water ? Give reason for
your observation.
What is the chemical name of dry ice ? Why is it called dry ice. How is it prepared ?
Define the term – solution. Identify the solute and solvent in the following solutions –
(i) Tincture of iodine
(ii) Polluted air
(iii) soda water
(iv) Dilute Hydrochloric acid
Answer the following questions :
(a) Out of boiling and evaporation which is a surface phenomenon ? Explain.
(b) In the absence of a refrigerator butter is kept wrapped in a wet cloth during summer. Why ?
(c) Why do ice–cream appears colder than water at the same temperature ?
Particles of matter are continuously moving. Demonstrate this property of matter giving an
activity.
What do you mean by crystallization ? How can we get pure copper sulphate from impure
sample by this process ?
(a) Describe an activity to illustrate that gases do not have a fixed shape and volume.
(b) Liquids and gases are called fluids. In what way do they differ from each other ?
Compare solution, suspension and colloids in terms of :
(a) stability
(b) filterability
(c) Tyndall effect
„Water is considered as a compound of Hydrogen and Oxygen and not a mixture of
Hydrogen and Oxygen.‟ Comment on this statement.
Differentiate between a compound and a mixture (any three points)
Why do different liquids melt and boil at different temperatures?
Is melting and freezing point of a substance same? Explain taking into consideration latent
heat.
23g of salt is dissolved in 100g of water at 293 K. What is the concentration of solution at this
temperature ?
Give an example each of a mixture which shows following
characteristics :
(a) A mixture of two coloured components.
(b) A mixture of two volatile components with a boiling point difference less than 25 K.
(c) A mixture of a volatile and a non-volatile solid component.
What do you observe when ice cubes are put in a beaker containing water ? Give reason for
your observation.
Define the term – solution. Identify the solute and solvent in the following solutions –
(i) Tincture of iodine
(ii) Polluted air
(iii) soda water
(iv) Dilute Hydrochloric acid
(a) What is meant by the word ‘Latent’ in latent heat.
(b) Explain with example of water :
(i) latent heat of fusion, and
(ii) latent heat of vaporization
What are Aerosols ? Give any two examples
Name the technique to separate the following :
(i) Butter from cream
(ii) Ammonium chloride from sodium chloride
(iii) Salt from sea water
(iv) Oil from water
(v) Tea leaves from tea
(vi) Iron pins from sand
Convert the following temperatures to celsius scale
(i) 400 K (ii) 373 K
Write the following temperature in Kelvin Scale.
(i) Melting point of ice
(ii) Normal human body temperature
During an experiment, the students were asked to prepare a 10% (Mass/mass) solution of salt
in water. Rahul dissolved 10 g of salt in 100 g of water while Priya prepared it by dissolving
10 g of salt in water to make 100 g of solution(a) Do the two solutions have same concentration ?(b) Calculate mass/mass percentage in each case.(c) Whose measurements are correct for the experiment ?
(a) Comment how evaporation is a surface phenomenon whereas boiling is a bulk
phenomenon.
(b) Explain why wet clothes dry faster when we spread them out ?
How can you separate the following mixtures ?
(a) petrol and diesel from crude oil
(b) sand and iron filings
(c) drugs from blood
(d) Raw rice and dal
‘Colloidal solution appears to be homogeneous but actually it is heterogeneous’. Give
justification for this statement.
With the help of an activity show that gases are more easily compressible than liquids and
solids.
Explain what is a mixture? Name the two types of mixtures. List two points of difference
between them. How would you confirm that a colourless liquid given to you is pure water?
(a) Illustrate an activity to demonstrate that particles of matter have spaces between them.
(b) Explain why a diver is able to cut through water in a swimming pool.
Why is oxygen called a gas ? Give two reasons
(a) Give reason : Gases exert pressure on the walls of the container.
(b) Gases undergo diffusion very fast.
(a) Sodium chloride contains two elements, but it is still a pure substance. Give
reason.
(b) How would you confirm that a colourless liquid given to you is pure water ?
(a) Answer the following :
(i) A sponge can be compressed yet it is a solid. Why ?
(ii) Out of honey or ink which will diffuse faster and why ?
(b) List out three characteristics of particles of matter.
State two factors which determine the rate of diffusion of a liquid in to another liquid.
(a) Tyndall effect can be observed when sunlight passes through a canopy of dense forest.
Explain it.
(b) Give any two examples of colloids
(a) Name a technique to separate a mixture of two or more miscible liquids for which
difference in boiling points is less than 25 K.
(b) Describe the structure of the column used in the above technique. Why is it used ?
Illustrate the technique of chromatography. What is the principle behind this technique ?
Write any two applications of this technique.
(a) Convert 574 K to the Celsius scale.
(b) What will be the state of water at :
(i) 10C (ii) 275 K (iii) 370 K
(c) Give reason – why water at room temperature is a liquid
Differentiate between bone and cartilage.
Classify the following as metals, non-metals, compounds and mixtures.
Hydrogen, sodium, milk, carbon dioxide, air, mercury.
Name the states of matter that :
(a) has definite shape, volume and mass.
(b) has minimum force of attraction between the particles.
(c) has maximum force of attraction between the particles.
Define solid state of matter. State properties associated with this state.
A black and a red suitcase were tied to the car roof. It takes 5 ropes to keep a black
suitcase from falling down a car while turning and only two ropes to keep the red
suitcase from falling down. From this fact what do you conclude about the relative
weight of the two suitcases ? Justify your answer on the basis of Newton‟s Law of
motion. Also state the Law.
You are given a mixture of alcohol and water. Explain the process to separate it into its
constituents. Draw a labelled diagram of the technique used .
What is dry ice ? How is it prepared ?
Compare the following in three states of matter.
(a) Particle motion
(b) Force of attraction between particles
(c) Space between particles
(a) How can we separate a mixture of sodium chloride and ammonium chloride? Draw a
labelled diagram to show the set up for the process.
(b) Name two more substances which can be separated from their mixture by the above
method.
(a) Define diffusion. Explain the rate of order of diffusion in solids, liquids and gases.
(b) State the effect of temperature on diffusion
Pick the odd one out from : Golgi Apparatus, Endoplasmic Reticulum (E.R), Cytoplasm,
Lysosomes. Give suitable reason for your selection.
Write the net force acting on a bus, of mass 2000 kg, moving with a uniform velocity of
60km/h.
(a) What are heterogeneous mixtures ?
(b) Why mixture does not have a fixed melting or a fixed boiling point ? Give two
reasons.
Why the inter-conversion of states of matter is considered as a physical change? Give three
reasons to justify your answer.
Define the latent heat of vapourisation. Why the particles of steam possess more energy than
water at the same temperature?
(a) If 110 g of salt is present in 550 g of solution, then calculate the concentration of the
solution.
(b) Explain the terms unsaturated solution, saturated solution and solubility
(a) Explain the effect of temperature on the movement of particles of matter.
(b) Give reason why we get smell of hot sizzling food even when we are metres away
from it ?
23g of salt is dissolved in 100g of water at 293 K. What is the concentration of solution at this
temperature
What will be the state of water at :
(i) 10C (ii) 275 K (iii) 370 K
(c) Give reason – why water at room temperature is a liquid?
Rohit added small amount of common salt to water taken in a graduated cylinder. On
dissolution there was no detectable change in the level of water. Explain why is it so ?
Calculate the mass of water and mass of glucose required to make 250g of 40% solution of
glucose.
Compare a suspension and a colloidal solution on the basis of :
(a) type of mixture
(b) particle size
(c) scattering of light
(d) stability
Give one example each suspension and colloidal solution
Burning and Boiling are two different types of changes. List three points of difference between them.
State the SI unit of temperature. Mention the boiling point of water and average human body
temperature in SI unit.
Give an example each of a mixture which shows following
characteristics :
(a) A mixture of two coloured components.
(b) A mixture of two volatile components with a boiling point difference less than 25 K.
(c) A mixture of a volatile and a non-volatile solid component
Three students A, B and C prepared mixtures using chalk powder, common salt and milk
respectively in water. Whose mixture –
(a) would not leave residue on filter paper after filtration ?
(b) would show tyndall effect ?
(c) would give transparent /clear solution ?
(d) would settle down at the bottom when left undisturbed ?
(e) could be filtered by filter paper ?
State one point of difference between solid, liquid and gas with respect to :
(a) Shape
(b) Fluidity
(c) Kinetic energy
(d) Force of attraction
(e) density
(a) How tincture of iodine is prepared ?
(b) Define solubility.
(c) What would happen if you were to take a saturated solution at a certain temperature
and cool it slowly ?
Describe an activity to show that air contains water vapours
(a) A sponge can be compressed, yet it is a solid why ? Explain.
(b) Name the state of matter that has minimum space between particles.
Differentiate between physical and chemical change in three points. Classify the following as
physical or chemical change –
(a) Water freezes to form ice.
(b) Sugar is dissolved in water
(c) Burning of paper.
(d) Rusting of iron.
State the separation technique used for the separation of the following :
(a) Ammonium chloride from a mixture containing sodium chloride and ammonium
chloride
(b) Copper sulphate from its solution in water.
In cities drinking water is supplied from water works to your homes. Draw a flow diagram of
water works for supply of pure drinking water.
(a) Calculate the mass of potassium chloride required to prepare its 20% solution in 100 g
of water.
(b) Explain the term solubility and the effect of temperature on it.
