April
MATTER IN OUR SURROUNDINGS
SECTION A
1
Match the following terms with their respective examples/definitions:
1.Evaporation A. Conversion of solid directly to gaseous state
2.Latent heat of vapourisation B.Increases if impurity is present
3.Latent heat of fusion C.Gas to liquid to solid
4.Diffusion D. No change is temperature is seen
5. Melting point E. Smell of perfume in a room
6. Boiling point F. Burns caused due to steam
7. Sublimation G.Drinking tea from a saucer
8. Interconversion of matter H.Of ice is 00c
Solids have a regular geometrical shape whereas liquids do not. Explain why?
3
Give one common characteristic between:
a
Solids and liquids
b
Liquids and gases
4
a
Do all liquids whether miscible or immiscible diffuse into one another?
b
Which form of matter is more energetic: liquids or gases? Why?
c
Is it correct to state that matter is continuous in nature? Comment
2
5
Reading Comprehension
Every thing on earth can be explained in terms of 5 states (phases)of matter-solid,
liquid, gas, plasma and-Bose Einstein condensate. A substance in a solid phase is
relatively rigid ,has a definite volume and shape. Liquids have a definite volume ,but
are able to change their shape by flowing. Liquids are similar to solids in that the
particles touch. However the particles are able to move around. Since the particles
are able to touch the densities of liquid will be close to that of a solid. Since the liquid molecules can move they will take the shape of their container. Gases have no definite volume or shape .If unconstrained, gases will spread out indefinitely. If
confined they will take the shape of the container. This is because gas particles
have enough energy to overcome attractive forces. Each of the particles are well a
separated resulting in very low density. The fourth state of matter is plasma. Plasma
is an ionized gas. A gas into which sufficient energy is provided to free electrons
from atoms or molecules and to allow both species ions and electrons ,to coexist. The collapse of the atom into a single quantum state is known as Bose Condensation or Bose Einstein condensation .It is now considered as the fifth state of matter.
a
Give the names of five states of matter.
b
Write short notes on general properties of a solid..
c
Write short notes on general properties of a liquid
d
What is Bose Condensate?
e
What is plasma?
6
Take 2-3 crystals of potassium permanganate and dissolve them in 100 ml of water.
Take out approximately10 ml of this solution and put it into 90 ml of clear water.
Keep diluting the solution like this for 5-8 times.
Answer the following questions on the basis of observations made during the above activity
a
Is the water still coloured? Does the intensity of the coloration remain the same?
b
What does the above activity show?
c
What do you conclude from the above activity?
d
What will happen if we use 2ml of Dettol instead of potassium permanganate?
3
7
Take a 100 ml cylinder.
Fill half the cylinder with water and mark the level of water.
Dissolve common salt/sugar with the help of a glass rod.
Observe any change in water level.
a
What do you think happened to the salt/sugar?
b
Where does it disappear?
c
Does the level of water change?
8
Take two beakers filled with water. Put a drop of KMnO4 slowly and carefully along the sides of the first beaker and honey in the same way in the second beaker.
Answer the following questions on the basis of observations made during the above activity.
a
What change is observed in the two beakers?
b
In which beaker has the change occurred more quickly?
c
Name the process involved in the observed change.
d
Why is the time taken for the change to occur different in the two beakers.
9
Drop a crystal of copper sulphate into a glass of hot water and another containing cold
water. Do not stir the solution. Allow the crystals to settle at the bottom.
a
What do you observe just above the solid crystal in the glass?
b
What happens as time passes?
c
What does this suggest about the particles of solid and liquid?
4
d
Does the rate of mixing change with temperature? Why and how?
SECTION B
Choose the correct alternative
1
Which of the following sets of phenomena would increase on raising the temperature?
a
Diffusion, evaporation , compression of gases
b
Evaporation , Diffusion, solubility of gases
c
Evaporation, compression of gases , solubility of gases
d
Evaporation , diffusion , compression of gases , solubility of gases
2
Meena visited a natural gas compression unit and found that the gas can be compressed
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
3
On converting 250C, 380C and 660C to Kelvin scale the correct sequence of temperature
would be
a
298 K ,311K ,339 K
b
298K ,300K ,338K
c
273K,278K,543K
d
298K ,310K ,338K
4
The boiling points of diethyl ether , acetone and n –butyl alcohol are 350C ,560C and 1180C
respectively. Which of the following correctly represents the boiling point in Kelvin scale
a
306K,329K, 391K
b
308K, 329 K ,392 K
c
308K, 329 K, 391 K
d
329 K ,392 K, 308K
5
Which conditions 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
6
In which of the following conditions, the distance between the molecules of the 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 (iii)
b
(i) and (iv)
c
(ii) and (iii)
d
(ii) and (iv)
5
7
If 1 kg of warm water completely turned into ice which of the following would change
(i) its state
(ii) its mass
(iii)its temperature
(iv)its chemical nature
a
only(i) and (iii)
b
only(ii) and (iv)
c
only(iii) and (iv)
d
only(i) (ii) and (iv)
8
The temperature at which the vapour pressure of the liquid becomes equal to the
atmospheric pressure is called
a
boiling point
b
melting point
c
freezing point
d
none of these.
9
Study the figures given below carefully. What can be inferred from these figures
a
The gas particles have very less kinetic energy
b
The gas particles have a lot of space between them
c
Gases ca be easily compressed
d
Both (b)&(c)
10
Which of the following statements is not correct –
a
The density of ice is less than the density of water.
b
To convert a temperature on the Kelvin scale to Celsius scale, subtract 273 from the given
temperature.
c
To convert a temperature on the Celsius scale to Kelvin scale, add 273 to the given
temperature.
d
Vaporisation of a liquid causes cooling.
11
Which one of the following is an incorrect statement?
a
Cooling is produced during melting
b
The temperature changes steadily on heating.
c
The melting point of ice is 00C.
d
Once melting starts, the temperature stays at 00C until all the ice has melted.
12
When heat is supplied to a solid substance
a
the kinetic energy of the particles increases.
b
the potential energy of the particles increases
c
the potential energy of the particles decreases
d
the potential energy of the particles decreases
13
A substance melts at -250 C and boils at 850 C, Which of the following statements about it is correct?
a
It would be in solid state at -150C
b
It would be in gaseous state at -900C
c
It would be in liquid state at -250C
d
It can in liquid state or in gaseous state at -850C
6
14
Melting points of four solids A, B, C and D are 780 C, 2620 C, 1000 C and 1680 C Inter
particle forces of attraction are in the order
a
A>C>D>B
b
B>C>D>A
c
A>D>C>B
d
B>D>C>A
15
In the experiment shown below cotton pads are dipped in ammonia and hydrogen chloride
respectively and placed at opposite ends of a glass tube. When particles of ammonia
come in contact with particles of hydrogen chloride, they react to form a white solid
called ammonium chloride which is seen in the form of a white cloud
It is known that particles of ammonia travel 1.5 times faster than particles of hydrogen
chloride. In the figure given below, where is the white cloud likely to be formed?
16
The given graph represents the heating curve of a substance (solid)which is heated at a constant rate over a period of time. Observe the graph carefully and answer the question
i
On the heating curve diagram ,the section representing only liquid is
a
PQ
b
QR
c
RS
d
ST
ii
Identify the process that takes place during line segment ST of the heating curve
a
Melting
b
Sublimation
c
Evaporation
d
Vaporisation
7
17
In the experiment of determination of boiling point of water, a graph between time and thermometer reading was drawn. From the graph the correct boiling point of water is
a
100
b
99
c
99.5
d
99.9
SECTION C
1
Carbon dioxide gas is heavier than both nitrogen and oxygen. Why does not it form
lower layer in the atmosphere?
2
Why is it not proper to regard the gaseous state of ammonia as vapours?
3
Kelvin scale of temperature is regarded as better than the Celsius scale, Assign reason
4
Explain why there is no rise in temperature of a substance when it undergoes a change of state although it is still being heated.
8
5
Name one property which is shown by naphthalene and not by sodium chloride.
6
Why does water become cold if we add some ice cubes to it?
7
When ice comes in contact with skin, there is a cooling sensation. However, in case of steam severe burns are formed on the skin. How will you account for this?
8
Anita 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. Explain.
9
Osmosis can be regarded as a special case of diffusion. Explain.
9
10
In severe cold a family burnt wood in the room during the night by keeping the windows close. After sometime they felt suffocated. They immediately opened the windows and got relief. What did actually happen?
11
Small quantities of water and ether are placed on the palms of both the hands. Which will experience more cooling?
12
A substance was highly compressible and could be easily liquefied. It could also take up the shape of any container. Predict the nature of the substance. Enlist four properties of this state of matter.
13
When sugar is dissolved in water, there is hardly an increase in volume. Which characteristic of matter is illustrated by this observation
10
14
Differentiate between evaporation and vapourisation.
15
What is dry ice? What happens when the pressure under which it is stored is decreased to 1 atmosphere?
16
The table below shows the melting points, boiling points and densities of substances A to D
Substance
Melting point/0C
Boiling point/0C
Density/g cm -3
A
1110
2606
9.1
B
-266
-252
0.07
C
40
94
1.6
D
-14
60
0.9
a
Which substance is a gas at room temperature?
b
Which substance is a liquid at room temperature?
c
Which substances are solids at room temperature?
d
Which substance is most likely to be a metal?
e
Which substance will be a liquid at -2600C?
11
f
What is the melting point of the least dense nonmetal?
g
Which substance is a gas at 720C?
17
Give the full forms of (i) LPG (ii) CNG
18
Which characteristic of gas is used in supplying oxygen cylinders to hospitals?
19
What will happen when we start putting pressure and compress a gas enclosed in a
cylinder? Do you think that increasing or decreasing the pressure and temperature
can change the state of matter. Justify your answer with an example.
20
The melting points of 2 substances A & B are 280 K and 320 K respectively. Are these
substances liquid at room temperature ? Justify your answer.
21
Explain with the help of an activity that matter is made up of particles.
12
22
A sample of water was heated from 25°C to 30°C.
a
What were the initial and final temperatures of water in Kelvin scale?
b
How much was the rise in temperature on Celsius scale?
The phenomenon of change of liquid into vapour at any temperature below its boiling point is called evaporation
Evaporation is a surface phenomenon
Rate of evaporation depends on
(a) Surface area
(b) Temperature
(c) Vapours of the liquid (humidity in case of water) in the surroundings
(d) Speed of wind
(f) Nature of the liquid
Value based questions
1
A student spilled a bottle of ammonia in one corner of the laboratory. Soon the whole laboratory was filled with a pungent irritating smell. One of the students started feeling nauseas. The other students immediately opened the windows and doors and switched on the exhaust fans. After sometime, the student complaining of nausea got relief..
a
Explain what actually did happen?
b
What values are exhibited by the students towards their classmate?
2
Harsh hurt himself while playing in a football tournament. His friends took him to a doctor who advised that Harsh would need some stitches to heal the wound. The doctor performed a minor surgery by spraying ether on a portion of his wound. After the minor surgery Harsh was escorted home by his friends.
a
Why did the doctor spray ether on his wound to perform the surgery?
b
What values are exhibited by Harsh’s friends?
18
QUESTION BANK
1
How is the kinetic energy of the constituent particles of any matter affected by a
change in temperature?
2
With the help of an activity show that air contains water vapours.
3
How can the phenomenon of evaporation be explained in terms of the kinetic
molecular theory?
4
Differentiate between gas and vapour.
5
Why do we feel uncomfortable when the humidity is very high?
6
Why solids do not possess fluidity?
7
Butter is generally wrapped in wet cloth during summer if no refrigerator is available. Explain.
8
Interparticle spaces present in all types of matter. Justify your answer.
9
Solids are generally heavy while gases are light. Explain.
10
CO2 is a gas. Justify the given statement by two reasons.
11
Express the boiling point of water in Celsius as well as kelvin scale.
12
Give reasons
a
Steam produces more severe burns than boiling water.
b
We are able to sip hot tea faster from a saucer rather than a cup.
c
Water kept in an earthen pot becomes cool during summer.
d
Steam produces more severe burns as compared to boiling water.
e
We wear cotton clothes during summer
13
At what temperature does solid ice and liquid water co - exist together?
14
What is the effect of the following on the rate of diffusion? (a) temperature(b) density of liquid
15
Predict the physical state of matter in each case from the following characteristics.
a
It has a definite volume but no definite shape
b
It is rigid and highly incompressible.
c
Kinetic energy of particles is minimum in this state.
d
It represents the most highly compressible form of matter.
16
a
Convert the following to Celsius scale (i)400K (ii) 373K
b
Convert the following to Celsius scale (i)270C (ii) 7000C
17
Arrange the following substances in increasing order of force of attraction between the
particles (a) water(b) hydrogen(c) sand
18
Gases can be compressed but not solids. Explain
19
A rubber band changes its shape when stretched. Can it be regarded as solid?
20
Draw (assignment sheet)
a
Schematic representation of three states of matter and compare the motion of particles
b
Sublimation of ammonium chloride
c
apparatus showing conversion of ice to water
