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Which of the following are matter ?
Chair, air, love, smell, hate, almonds, thought, cold, cold drink, smell of perfume
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Give reasons for the following observation:
The smell of hot sizzling food reaches you several metres away, but to get smell from cold food, you have to go close.
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A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?
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What are the characteristics of the particles of matter?
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The mass per unit volume of a substance is called density.
(Density = mass/volume)
Arrange the following in order of increasing density - air, exhaust from chimneys, honey, water, chalk, cotton and iron.
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(a) Tabulate the differences in the characteristics of states of matter.
(b) Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy and density
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Give reasons.
(a) A gas fills completely the vessel in which it is kept.
(b) A gas exerts pressure on the walls of the container.
(c) A wooden table should be called a solid.
(d) We can easily move our hand in air but to do the same through a solid block of wood we need a karate expert.
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Liquids generally have lower density as compared to solids. But you must have observed that ice floats on water. Find out why?
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Convert the following temperatures to celsius scale :
(a) 300 K (b) 573 K.
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What is the physical state of water at :
(a) 250°C (b) 100°C?
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For any substance, why does the temperature remain constant during the change of state?
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Suggest a method to liquefy atmospheric gases.
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Why does a desert cooler cool better on a hot dry day?
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How does the water kept in an earthen pot (matka) become cool during summer?
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Why does our palm feel cold when we put some acetone or petrol or perfume on it?
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Why are we able to sip hot tea or milk faster from a saucer rather than a cup?
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What type of clothes should we wear in summer?
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Convert the following temperatures to Celsius scale :
(a) 293 K (b) 470 K
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Convert the following temperatures to the Kelvin scale :
(a) 25°C (b) 373°C
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Give reasons for the following observations :
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.
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Arrange the following substances in increasing order of forces of attraction between the particles: water, sugar, oxygen.
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What is the physical state of water at
(a) 25°C (b) 0°C (c) 100°C ?
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Give two reasons to justify that:
(a) Water at room temperature is a liquid.
(b) An iron almirah is a solid at room temperature.
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Why is ice at 273 K more effective in cooling than water at the same temperature ?
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What produces more severe burns, boiling water or steam ?
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Name A, B, C, D, E and F in the following diagram showing change in its state.
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question_answer27)
Which one of the following sets of phenomena would increases on raising
the temperature?
(a) Diffusion, evaporation, compression of gases
(b) Evaporation, compression of gases, solubility
(c) Evaporation, diffusion, expansion of gases
(d) Evaporation, solubility, diffusion, compression of
gases
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question_answer28)
Seema visited a Natural Gas Compressing Unit and found
that the gas can be liquefied under specific conditions of temperature and
pressure. While sharing her experience with friends she got confused. Help her
to identify the correct set of conditions.
(a) Low temperature, low pressure (b)
High temperature, low pressure
(c) Low temperature, high pressure (d)
High temperature, high pressure
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question_answer29)
The property to flow is unique to fluids. Which one of the
following statements is correct?
(a) Only gases behave like fluids (b)
Gases and solids behave like fluids
(c) Gases and liquids behave like fluids (d)
Only liquids are fluids
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question_answer30)
During summer, water kept in an earthen pot becomes cool
because of the phenomenon of
(a) diffusion (b) transpiration (c)
osmosis (d) evaporation
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question_answer31)
A few substances are arranged in the increasing order of
'forces of attraction' between their particles. Which one of the following
represents a correct arrangement?
(a) Water, air, wind (b) Air, sugar, oil (c)
Oxygen, water, sugar (d) Salt, juice, air
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question_answer32)
On converting 25°C, 38°C and 66°C to kelvin scale, the
correct sequence of temperature will be
(a) 298 K, 311 K and 339 K (b)
298 K, 300 K and 338 K
(c) 273 K, 278 K and 543 K (d)
298 K, 310 K and 338 K
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question_answer33)
Choose the correct statement of the following.
(a) Conversion of solid into vapours without passing
through the liquid state is called vaporization.
(b) Conversion of vapours into solid without passing
through the liquid state is called sublimation.
(c) Conversion of vapours into solid without passing
through the liquid state is called freezing.
(d) Conversion of solid into liquid is called sublimation.
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question_answer34)
The boiling points of diethyl ether, acetone and n-butyl
alcohol are 35°C, 56°C and 118°C, respectively. Which one of the following
correctly represents their boiling points in kelvin scale?
(a) 306 K, 329 K, 391 K (b) 308 K, 329 K, 392 K (c)
308 K, 329 K, 391 K (d) 329 K, 392 K, 308 K
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question_answer35)
Which condition out of the following will increase the
evaporation of water
(a) Increase in temperature of water (b)
Decrease in temperature of water
(c) Less exposed surface area of water (d)
Adding common salt to water
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question_answer36)
In which of the following conditions, the distance between
the molecules of hydrogen gas would increase?
(i) Increasing pressure on hydrogen contained in a closed
container.
(ii) Some hydrogen gas leaking out of the container.
(iii) Increasing the volume of the container of hydrogen
gas.
(iv) Adding more hydrogen gas to the container without
increasing the volume of the container.
(a) (i) and (ii) (b) (i) and (iv) (c)
(ii) and (iii) (d) (ii) and (iv)
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question_answer37)
A sample of water under study was found to boil at 102°C
at normal temperature and pressure. Is the water pure? Will this water freeze
at 0°C? Comment.
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question_answer38)
A student heats a beaker containing ice and water. He
measures the temperature of the content of the beaker as a function of time.
Which of the following would correctly represent the result? Justify your
choice.
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question_answer39)
Fill in the blanks.
(a) Evaporation of a liquid at room temperature leads to
a........... effect.
(b) At room temperature the forces of attraction between
the particles of solid substances are?........ than those which exist in the
gaseous state.
(c) The arrangement of particles is less ordered in the?.........
state. However, there is no order in the?......... state.
(d) ??........ is the change of gaseous state directly to
solid state without going through the?......... state.
(e) The phenomenon of change of a liquid into the gaseous
state at any temperature below its boiling point is called............... .
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question_answer40)
Match the physical quantities given in Column A to their
SI units given in Column B.
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Column A
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Column B
|
|
(a)
|
Pressure
|
1.
|
Cubic metre
|
|
(b)
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Temperature
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2.
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Kilogram
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|
(c)
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Density
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3.
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Pascal
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(d)
|
Mass
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4.
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Kelvin
|
|
(e)
|
Volume
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5.
|
Kilogram per cubic metre
|
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question_answer41)
The non-SI and SI units of some physical quantities are
given in Column A and Column B respectively. Match the units belonging to the
same physical quantity.
|
Column A
|
Column B
|
|
(a)
|
Degree Celsius
|
1.
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Kilogram
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|
(b)
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Centimeter
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2.
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Pascal
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|
(c)
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Gram per centimeter cube
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3.
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Metre
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|
(d)
|
Bar
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4.
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Kelvin
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|
(e)
|
Milligram
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5.
|
Kilogram per metre cube
|
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question_answer42)
'Osmosis is a special kind of diffusion'. Comment.
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question_answer43)
Classify the following into osmosis/diffusion.
(a) Swelling up of a raisin on keeping in water.
(b) Spreading of virus on sneezing.
(c) Earthworm dying on coming in contact with common salt.
(d) Shrinking of grapes kept in thick sugar syrup.
(e) Preserving pickles in salt.
(f) Spreading of smell of cake being baked throughout the
house.
(g) Aquatic animals using oxygen dissolved in water during
respiration.
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question_answer44)
Water as ice has a cooling effect, whereas water as steam
may cause severe burns. Explain these observations.
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question_answer45)
Alka was making tea in a kettle. Suddenly she felt intense
heat from the puff of steam gushing out of the spout of the kettle. She
wondered whether the temperature of the steam was higher than that of the water
boiling in the kettle. Comment.
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question_answer46)
A glass tumbler containing hot water is kept in the
freezer compartment of a refrigerator (temperature < 0° C). If you could
measure the temperature of the content of the tumbler, which of the following
graphs would correctly represent the change in its temperature as a function of
time
(a)
(b)
(c)
(d)
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question_answer47)
Look at the figure and suggest in which of the vessels A, B, C or D, the rate
of evaporation will be the highest? Explain.
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question_answer48)
(a) Conversion of solid to vapour is called sublimation.
Name the term used to denote the conversion of vapour to solid.
(b) Conversion of solid state to liquid state is called
fusion; what is meant by latent heat of fusion?
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question_answer49)
You are provided with a mixture of naphthalene and
ammonium chloride by your teacher. Suggest an activity to separate them with
well labeled diagram
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question_answer50)
It is a hot summer day, Priyanshi and Ali are wearing
cotton and nylon clothes respectively. Who do you think would be more
comfortable and why?
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question_answer51)
You want to wear your favourite shirt to a party, but the
problem is that it is still wet after a wash. What steps would you take to dry
it faster?
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question_answer52)
Comment on the following statements.
(a) Evaporation produces cooling.
(b) Rate of evaporation of an aqueous solution decreases
with increase in humidity.
(c) Sponge though compressible is a solid.
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question_answer53)
Why does the temperature of a substance remain constant during its melting
point or boiling point?
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