Class 9 Science CBSE worksheet for matter in our Surroundings
Given below are the Class 9 Science CBSE worksheet for matter in our Surroundings with answers
(a) Very Short questions
(b) True and False problems
(c) Fill in the blank's
(d) Short Answer type
(e) Match the column
(f) Olympiad Level Questions
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Fill in the blanks:-
Question 1.
a. Matter is made up of small_________.
b. The forces of attraction between the particles are _______ in solids, ______ in liquids and _________ in gases.
c. __________ is the change of gaseous state directly to solid state without going through liquid state, and vice-versa.
d. Evaporation causes __________.
e. Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its ________.
f. Solid, liquid and gas are called the three _______ of matter.
g. The smell of perfume gradually spreads across a room due to ______.
h. Rapid evaporation depends on the ______ area exposed to atmosphere.
i. As the temperature of a system increases, the pressure of the gases ______.
j. As the volume of a specific amount of gas decreases, it’s pressure _______.
k. As the temperature of a gas decreases, I’s volume ______.
l. Gas molecules at higher temperatures have more _______ than at cooler temperatures.
m. Usually the total charge of a plasma is _______.
n. The pressure inside of a sealed tube if you raise the temperature go ______
o. Forces of attraction in liquids are _______ than in olid.
p. Liquids that move quickly downhill are described as having _____. Solution
Fill in the blanks
a. Particles
b. Maximum, intermediate, minimum
c. Sublimation
d. Cooling
e. Melting point
f. States
g. Diffusion
h. Surface
i. Increases
j. Increases
k. Decreases
l. Kinetic energy
m. Zero
n. Up
o. Weaker
p. Low viscosity
True and False
Question 2.
a. Boiling is a bulk phenomenon.
b. Evaporation is a surface phenomenon.
c. The rate of evaporation depends only on the surface area exposed to the atmosphere.
d. Latent heat of vaporization is the heat energy required to change 1 kg. of a liquid to gas at atmospheric pressure at its melting point.
e. Water at room temperature is a liquid.
f. Atoms in a liquid are father apart than the atoms in a gas.
g. The molecules in a gas are in constant motion.
h. Gases present in air have the same pressure throughout the entire atmosphere.
i. All materials move from solid to liquid to gas as the temperature increases.
j. Because electrons have been stripped away from atoms in plasma, plasmas have a negative charge.
k. It is just as easy to compress a liquid, as it is to compress a gas.
l. Evaporation and boiling are the same processes because molecules move from a liquid to gaseous state.
m. If we pour liquid nitrogen($N_2$) into a glass, it will change its state to a solid.
n. You may find plasma in a star.
o. A system that changes from a solid state to a liquid state gains energy.
p. Plasmas are all made of the same ions. They have different colours due to different amounts of electricity. Solution
True/ False
a. True
b. True
c. False
d. False
e. True
f. False
g. True
h. False
i. True
j. False
k. False
l. False
m. False
n. True
o. True
p. False
Very Short Answer Questions-
Question 3.
a. Name the three states of matter. Give one example of each.
b. What are the two ways in which the physical state of matter can be changed?
c. Explain how gases can be liquefied?
d. What is sublimation? Give examples.
e. Define latent heat of fusion.
f. Define latent heat of vaporization.
g. What produces more severe burns, boiling water or steam?
h. How can the boiling point of a liquid be rased, without adding any impurity?
i. In how many forms did the earlier scientists classify matter?
j. Why does a summer rainstorm lower the temperature?
k. A beaker of a liquid with a vapour pressure of 350 torr at 25°C is set alongside a beaker of water (Vapour pressure of 23.76 torr) and both are allowed to evaporate. In which liquid does the temperature change at a faster rate? Why
l. At a given temperature, one liquid has a vapour pressure of 240 torr and another measure 420 torr. Which liquid probably has the lower boiling point? Which probably has the lower heat of vaporization?
m. A drop of dettol got evenly distributed in water. How?
n. Liquid nitrogen is used as a commercial refrigerant to flash freeze foods. Nitrogen boils at -196°C. What is this temperature on the Kelvin temperature scale?
o. What property or properties of gases can you point to support the assumption that most of the volume in a gas is empty space?
p. What is unit cell?
q. What is the effect on surface tension of temperature?
r. Surface tension is same for different liquids. Explain. Solution
a. Solid,liquid and gas are the three states Example Ice(Solid), Water(liquid) and steam(Gas)
b. Melting and boiling
c.By increasing pressure or increasing temperature
e.The amount of heat energy required to convert 1 kg of solid into liquid at atmospheric pressure at its melting point
f. The amount of heat energy required to convert 1 kg of liquid at its boling point to vapour or gas without any change in temperature g. Steam
g. Steam
i. Air,earth ,fire and water
k. Liquid other than water
l. Liquid with high vapour pressure has low boiling point and low heat of vaporization
m.There is enough space between particle of water and dettol
n. K = °C +273= -196+273=77K
o. Compressibility
p.Smallest portion of crystal lattice which defines completely the repeating pattern in the crystal in all the directions
q. Surface decrease with rise in temperature
r.Surface tension is different for different liquids
Question 4.
Explain why?
i. A gas fill a vessel completely.
ii. Camphor disappears without leaving any residue.
iii. The temperature does not rise during the process of melting and boiling, through heat energy is constantly supplied.
iv. Water stored in an earthen vessel becomes cool.
v. An iron almirah is a solid at room temperature. Solution
(i) Because the molecules of the gas moves freely so it occupies the whole space the vessel
(ii) camphor disappears after sometime as its surface gains kinetic energy and gets directly converted into gas. The process of geting converted directly into gas without getting converted into liquid is called sublimation. So, we can say that canphor due to sublimation gets converted into gas and gets dissaper after sometime.
(iii) the heat supplied is continuously used up in changing the state of the substance by overcoming the forces of attraction between the particles
(iv) Earthen pot has pores present on it which allow water, kept inside it to evaporate. This process takes energy from the water kept inside, as a result the water becomes cool.
(v) Iron has high melting and boiling point.So it is solid at room temperature
Question 5.
Which phenomenon occurs during the following changes?
ii. Wax melts in the sun.
iii. Drying of wet clothes
iv. Formation of clouds
v. Density of liquids is more than gases. Solution
(i)Sublimation
(ii) Wax is in solid state and it absorbs heat energy from sun and starts melting
(iii) Water molecules in the we clothes absorb heat energy from Sun and evaporate to atmosphere
(iv) Water vapours formed from ocean and other bodies. When it reaches atmosphere, they get cooled because of low temperature and condense into water
(v) Molecules are much closer in liquid as comparison to gas. hence Density of liquids is more than gases.
Question 6.
Arrange the state in increasing order of the forces of attraction between the particles
a)Liquid
b) Gas
c) Solid Solution
Gas ->Liquid ->Solid
Question 7.
On converting 25 0C, 38 0C and 66 0C 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 Solution
Question 10.
What is Plasma and Bose-Einstein Condensate? Solution
Plasma: The state consists of super energetic and super excited particles. These particles are in the form of ionised gases. The fluorescent tube and neon sign bulbs consist of plasma. Inside a neon sign bulb there is neon gas and inside a fluorescent tube there is helium gas or some other gas. The gas gets ionised, that is, gets charged whenelectrical energy flows through it.
The Bose-Einstein Condensate is formed by cooling a gas of extremely low density, about one-hundred-thousandth the density of normal air, to super low temperatures
Question 11. 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. Solution
The water will cool initially till it reaches 0°C, the freezing point. At this stage the temperature will remain constant till all the water will freeze. After this temperature would fall again..Hence (c)
Question 12.
Why does the temperature of a substance remain constant during its melting point or boiling point? Solution
The temperature of a substance remains constant at its melting and boiling points untill all the substance melts or boils because, the heat supplied is
continuously used up in changing the state of the substance by overcoming the forces of attraction between the particles. This heat energy absorbed without showing any rise in temperature is given the name latent heat of fusion/latent heat of vapourisation.
Question 13.
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 (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv) Solution
Both when Some hydrogen gas leaking out of the container and Increasing the volume of the container of hydrogen gas. hence Option (c)
Question 14.
Define:
i.Melting point
ii.Boiling point
iii.Vapourisation
iv.Freezing
v.Brownian motion Question 15.
Differentiate between amorphous and crystalline solids.
Foundation Level Questions for Olympiads/JEE Level/PMT/KVYP
Question 16.
Calculate each of the following quantities for an ideal gas
(a) The volume of the gas in liters, if 2.46 mol has a pressure of 1.28 atm at a temperature of -60C;
(b) The absolute temperature of the gas at which 4.79 x 10-2 mol occupies 135 mL at 720 torr;
(c) The pressure, in atmospheres, if 5.52 x 10-2 mol occupies 413 mL at 880C;
(d) The quantity of gas, in moles, if 88.4 L at 540C has a pressure of 9.84 kPa. Solution
All these questions can be derived using Ideal gas equation formula
PV=nRT
Where P = Pressure in Atm
V=Volume in Litres
n=No of Moles
T=temperature in Kelvin
Also unit conversion we need to remmeber
1 torr=1/760 atm
1 pa=1/101.3 atm
R = 0.0821 L-atm/mol- K
(a) 42.1 L
(b) 32.2 K
(c) 3.96 atm
(d) .319 mol
Question 17.
Vessel A contains CO(g) at 00C and 1 atm. Vessel B contains SO2 (g) at 200C and 0.5 atm. The two vessels have the same volume.
(a) Which contains more molecules?
(b) Which contains more mass?
(c) In which vessel is the average kinetic energy of molecules higher? Solution
(a) Vessel A
(b) Vessel B
(c) Vessel B
Summary
This Class 9 Science CBSE worksheet for matter in our Surroundings is prepared keeping in mind the latest syllabus of CBSE . This has been designed in a way to improve the academic performance of the students. If you find mistakes , please do provide the feedback on the mail.
