-
A balloon is filled with hydrogen at room temperature. It
will burst if pressure exceeds 0.2 bar. If at 1 bar pressure the gas occupies
2.27 L volume, upto what volume the balloon can be expanded?
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On a ship sailing in Pacific ocean when temperature is\[23.4{{\,}^{{}^\circ
}}C\], a balloon is filled with 2L air. What will be the volume of the balloon
when the ship reaches Indian ocean, where temperature is\[{{26.1}^{{}^\circ
}}C\]?
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At \[25{}^\circ C\]and 760 mm Hg pressure a gas occupies 600
mL volume. What will be its pressure at a height, where temperature is \[10{}^\circ
C\]and the volume of the gas is 640 mL?
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A neon gas-dioxygen gas mixture contains 70.6 g dioxygen and
167.5 g neon. If the pressure of the mixture of gases in the cylinder is 25 bar,
what is the partial pressure of dioxygen and neon in the mixture?
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Gases possess characteristic critical temperature which
depends upon the magnitude of intermolecular forces between the gas particles.
Critical temperature of ammonia and carbon dioxide are 405.5 K and 304.10 K
respectively. Which of these gases will liquefy first when you start cooling
from 500 K to their critical temperature?
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What will be the minimum pressure required to compress \[500\text{
}d{{m}^{3}}\]of air at 1 bar to \[200\text{ }d{{m}^{3}}\]at \[30{}^\circ C\]?
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A vessel of 120 mL capacity contains a certain amount of gas
at \[35{}^\circ C\]and 1.2 bar pressure. The gas is transferred to another
vessel of volume 180 mL at\[35{}^\circ C\]. What would be its pressure?
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Using the equation of state\[PV=nRT\], show that given temperature
density of a gas is proportional to gas pressure.
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At\[0{}^\circ C\], the density of a gaseous oxide at 2 bar
is the same as that of nitrogen at 5 bar. What is the molecular mass of the oxide?
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Pressure of 1 g of an ideal gas A at \[27{}^\circ C\]is
found to be 2 bar. When 2 g of another ideal gas B is introduced in the same
flask at same temperature, the pressure becomes 3 bar. Find the relationship
between their molecular masses.
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The drain cleaner, 'Drainex contains small bits of aluminium
which reacts with caustic soda to produce dihydrogen. What volume of hydrogen
at \[20{}^\circ C\]and one bar will be released when 0.15 g of aluminium
reacts?
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What mil be the pressure exerted (in pascal) by a mixture of
3.2 g of methane and 4.4 g of carbon dioxide contained in a\[9d{{m}^{3}}\]flask
at\[27{{\,}^{{}^\circ }}C\]?
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What will be the pressure of a gaseous mixture when 0.5 L of\[{{H}_{2}}\]
at 0.8 bar and 2.0 L of\[{{O}_{2}}\] at 0.7 bar are introduced in a 1 L vessel
at\[27{}^\circ C\]?
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The density of a gas is found to be \[5.46\text{
}g/d{{m}^{3}}\]at \[27{}^\circ C\] and
under 2 bar pressure. What will be its density at STP?
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34.05 mL of phosphorous vapour weighs 0.625 g at\[546{}^\circ
C\]and 1 bar pressure. What is the molar mass of phosphorous?
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A student forgot to add
the reaction mixture to the round bottom flask at \[27{}^\circ C\]but put it on
the flame. After a lapse of time, he realised his mistake. By using a
pyrometer, he found that the temperature of the flask was\[477{}^\circ C\].
What fraction of air would have been expelled out?
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Calculate the temperature of 4.0 moles of a gas occupying \[5d{{m}^{3}}\]
at 3.32 bar (R = 0.083 bar \[d{{m}^{3}}\,{{K}^{-1}}\,mo{{l}^{-1}}).\]
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Calculate the total number of electrons present in 1.4 g of dinitrogen
gas.
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How much time would it take to distribute one Avogadro's number
of wheat grains if \[{{10}^{10}}\] grains are distributed each second?
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Calculate the total pressure in
a mixture of 8 g of oxygen and 4 g of dihydrogen confined in a vessel of \[1\,d{{m}^{3}}\]at\[~27{}^\circ
C\].
\[(R=0.083\text{ }bar\text{
}d{{m}^{3}}{{K}^{-1}}mo{{l}^{-1}})\]
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Payload is defined as the
difference between the mass of displaced air and the mass of the balloon.
Calculate the payload when a balloon of radius 10 m and mass 100 kg is filled
with helium at 1.66 bar at\[27{{\,}^{{}^\circ }}C\]. (Density of air
\[=1.2kg\,{{m}^{-3}}\]and \[R=0.083\,bar\,d{{m}^{3}}{{K}^{-1}}mo{{l}^{-1}})\]
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Calculate the volume occupied by 8.8 g of\[C{{O}_{2}}\] at
31.1C and 1 bar pressure \[(R=0.083\text{ }bar\text{
L}{{\text{K}}^{-1}}mo{{l}^{-1}})\]
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2.9 g of a gas at \[95{}^\circ C\]occupied the same volume
as 0.184 g of dihydrogen at \[17{}^\circ C\]and at the same pressure. What is the
molar mass of the gas?
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A mixture of hydrogen and oxygen at one bar pressure contains
20% by weight of hydrogen. Calculate the partial pressure of hydrogen.
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What will be the SI unit for the quantity\[\frac{P{{V}^{2}}{{T}^{2}}}{n}?\]
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In terms of Charles law explain why\[-\text{
}273\text{ }{}^\circ C\]is the lowest possible temperature?
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Critical temperature for carbon dioxide and methane are\[31.1{}^\circ
C\]and\[-81.9{}^\circ C\]respectively. Which of these hasstronger
intermolecular forces and why?
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Explain the physical significance of van der Waals'parameters.
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question_answer29)
In the following questions only one
option is correct
A person living in Shimla
observed that cooking food without using pressure cooker takes more time. The
reason for this observation is that at high altitude :
(a) pressure increases (b)
temperature decreases
(c) pressure decreases (d)
temperature increases
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question_answer30)
Which of the following property
of water can be used to explain the spherical shape of rain droplets?
(a) Viscosity (b)
Surface tension
(c) Critical phenomena (d)
Pressure
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question_answer31)
A plot of volume (V) versus
temperature (T) for a gas at constant pressure is a straight line passing
through the origin. The plots at different values of pressure are shown in fig.
5.1. Which of the following order of pressure is correct for this gas?
(a)\[{{p}_{1}}>{{p}_{2}}>{{p}_{3}}>{{p}_{4}}\]
(b) \[{{p}_{1}}={{p}_{2}}={{p}_{3}}={{p}_{4}}\] (c)\[{{p}_{1}}<{{p}_{2}}<{{p}_{3}}<{{p}_{4}}\]
(d) \[{{p}_{1}}<{{p}_{2}}={{p}_{3}}<{{p}_{4}}\]
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question_answer32)
The interaction energy of London
force is inversely proportional to sixth power of the distance between two interacting
panicles but their magnitude depends upon :
(a) charge of interacting
particles (b) mass of interacting particles
(c) polarisability of
interacting particles (d) strength of permanent dipoles in the
particles
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question_answer33)
Dipole-dipole forces act between
the molecules possessing permanent dipole. Ends of dipoles possess 'partial
charges'. The partial charge is :
(a) more than unit electronic
charge (b) equal to unit electronic charge
(c) less than unit electronic
charge (d) double the unit electronic charge
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question_answer34)
The pressure of a 1:4 mixture of
dihydrogen and dioxygen enclosed in a vessel is one atmosphere. What would be
the partial pressure of dioxygen?
(a)\[0.8\text{ }\times
\text{1}{{0}^{5}}\text{ }atm\] (b) \[0.008N{{m}^{-2}}\] (c)
\[8\times {{10}^{4}}N{{m}^{-2}}\] (d) 0.25 atm
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question_answer35)
As the temperature increases,
average kinetic energy of molecules increases. What would be the effect of
increase of temperature on pressure provided the volume is constant?
(a) Increases (b)
Decreases (c) Remains same (d) Becomes half
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question_answer36)
Gases possess characteristic
critical temperature which depends upon the magnitude of intermolecular forces between
the particles. Following are the critical temperatures of some gases :
|
Gases
|
\[{{H}_{2}}\]
|
\[He\]
|
\[{{O}_{2}}\]
|
\[{{N}_{2}}\]
|
|
Critical temperature in kelvin
|
33.2
|
5.3
|
154.3
|
126
|
From the above data what would be the
order of liquefaction of these gases? Start writing the order from the gas
liquefying first :
(a) \[{{H}_{2}}.He,{{O}_{2}},{{N}_{2}}\]
(b) \[He,{{O}_{2}},{{H}_{2}},{{N}_{2}}\] (c) \[{{N}_{2}},{{O}_{2}},He,{{H}_{2}}\]
(d) \[{{O}_{2}},{{N}_{2}},{{H}_{2}},He\]
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question_answer37)
What is SI unit of viscosity
coefficient \[(\eta )\]?
(a) Pascal (b)
\[Ns{{m}^{-2}}\] (c) \[k{{m}^{-2}}s\] (d)
\[N{{m}^{-2}}\]
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question_answer38)
Atmospheric pressures recorded
in different cities are as follows :
|
Cities
|
Shimla
|
Bangalore
|
Delhi
|
Mumbai
|
|
\[p\]in \[N/{{m}^{2}}\]
|
\[1.01\times {{10}^{5}}\]
|
\[1.2\times {{10}^{5}}\]
|
\[1.02\times {{10}^{5}}\]
|
\[1.21\times {{10}^{5}}\]
|
Consider
the above data and mark the place at which liquid will boil first?
(a) Shimla (b)
Bangalore (c) Delhi (d)
Mumbai
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question_answer39)
Which curve in figure represents
the curve of ideal gas?
(a) B only (b)
C and D (c) E and F (d) A
and B
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question_answer40)
Increase in kinetic energy can
overcome inter molecular forces of attraction. How will the viscosity of liquid
be affected by the increase in temperature?
(a) Increase (b)
No effect
(c)Decrease (d)
No regular pattern will be followed
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question_answer41)
How does the surface tension of
a liquid vary with increase in temperature?
(a) Remains same (b) Decreases (c)
Increases (d) No regular pattern is followed
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question_answer42)
In the following questions
two or more options may be correct.
With regard to the gaseous state
of matter which of the following statements are correct?
(a) Complete order of molecules (b)
Complete disorder of molecules
(c) Random motion of molecules (d)
Fixed position of molecules
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question_answer43)
Which of the following figures
does not represent 1 mole of dioxygen gas at STP?
(a) 16 grams of gas (b)
22.7 litres of gas
(c) \[6.022\times {{10}^{23}}\]dioxygen
molecules (d) 11.2 litres of gas
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question_answer44)
Under which of the following two
conditions applied together, a gas deviates most from the ideal behaviour?
(a) Low pressure (b)
High pressure (c) Low temperature (d) High temperature
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question_answer45)
Which of the following changes
decrease the vapour pressure of water kept in a sealed vessel?
(a) Decreasing the quantity of
water
(b) Adding salt to water
(c) Decreasing the volume of the
vessel to one-half
(d) Decreasing the temperature
of water
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question_answer46)
If 1 g of each of the following
gases are taken at STP, which of the gases will occupy (a) greatest volume (b)
smallest volume?
\[CO,C{{H}_{4}},{{H}_{2}}O,NO\]
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question_answer47)
Physical properties of ice, water and
steam are very different. What is the chemical composition of water in all the
three states?
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question_answer48)
The behaviour of matter in
different states is governed by various physical laws. According to you, what
are the factors that determine the state of matter?
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question_answer49)
Use the information and data
given below to answer the questions (a) to (c) :
(i) Stronger intermolecular
forces result in higher boiling point.
(ii) Strength of
London-dispersion forces increases with the number of electrons in the
molecule.
(iii) Boiling point of \[HF,\text{
}HCl,\text{ }HBr\]and \[HI\]are 293 K, 189 K, 206 K and 238 K respectively.
(a) Which type of intermolecular
forces are present in the molecules \[HF,\text{ }HCl,\text{ }HBr\]and\[HI\]?
(b) Looking at the trend of
boiling points of \[HCl,\text{ }HBr\]
and HI, explain out of dipole-dipole interaction and London interaction,
which one is predominant here?
(c) Why is boiling point of
hydrogen fluoride highest while that of hydrogen chloride lowest?
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question_answer50)
What will be the molar volume of
nitrogen and argon at 273.15 K and 1 atm?
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question_answer51)
A gas that follows Boyle's law,
Charles' law and Avogadro's law is called an ideal gas. Under what conditions a
real gas would behave ideally?
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question_answer52)
Two different gases 'A' and 'B'
are filled in separate containers of equal capacity under the same conditions
of temperature and pressure. On increasing the pressureslightly the gas 'A'
liquefies but gas 'B' does not liquefy even on applying high pressure until it
is cooled. Explain this phenomenon.
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question_answer53)
Value of universal gas constant
(R) is same for all gases.
What is the physical
significance?
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question_answer54)
One of assumptions of kinetic
theory of gas states that "there is no force of attraction between the
molecules of a gas", how far is this statement correct? Is it possible to liquefy
an ideal gas? Explain.
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question_answer55)
The magnitude of surface tension
of liquid depends on the attractive forces between the molecules. Arrange the following
in increasing order of surface tension : water, alcohol (\[{{C}_{2}}{{H}_{5}}OH\])
and hexane \[[C{{H}_{3}}{{(C{{H}_{2}})}_{4}}(C{{H}_{3}})]\].
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question_answer56)
Pressure exerted by saturated
water vapour is called aqueous tension. What correction term will you apply to
the total pressure to obtain-pressure of dry gas?
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question_answer57)
Name the energy which arises due
to motion of atoms or molecules in a body. How is this energy affected when the
temperature is increased?
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question_answer58)
Name two intermolecular forces
that exist between HF molecules in liquid state.
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question_answer59)
One of the assumptions of
kinetic theory of gases is that there is no force of attraction between the
molecules of a gas.
State and explain the evidence
that the assumption is not applicable for real gases.
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question_answer60)
Compressibility factor, Z, of a
gas is given as
\[Z=\frac{PV}{nRT}:\]
(i)What is the value of Z for an
ideal gas?
(ii) For real gas what will be the effect
on value of Z above Boyle's temperature?
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question_answer61)
The critical temperature (\[{{T}_{c}}\])
and critical pressure (\[{{p}_{c}}\]) of\[C{{O}_{2}}\] are \[30.98{}^\circ C\]and
73 atm respectively. Can \[C{{O}_{2}}\] (g) be liquefied at \[32{}^\circ C\]and
80 atm pressure?
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question_answer62)
For real gases the relation
between P, V and T is given by van der Waals' equation :
\[\left(
p+\frac{a{{n}^{2}}}{{{V}^{2}}} \right)(V-nb)=nRT\]
where 'a' and 'b? are van der
Waals' constants, 'nb? is approximately equal to the total volume of the
molecules of a gas.
'a' is the measure of magnitude of
intermolecular attraction.
(i)
Arrange the following gases in the increasing order of ?b?. Give reason.
\[{{O}_{2}},C{{O}_{2}},{{H}_{2}},He\]
(ii) Arrange the following gases
in the decreasing order of magnitude of ?a?. Give reason.
\[C{{H}_{4}},{{O}_{2}},{{H}_{2}}\]
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question_answer63)
The relation between pressure exerted by
an ideal gas\[({{p}_{deal}})\] and observed pressure \[({{p}_{real}})\] is given
by the equation :
\[{{p}_{ideal}}={{p}_{real}}+\frac{a{{n}^{2}}}{{{V}^{2}}}\]
If pressure is taken in\[N{{m}^{-2}}\],
number of moles in mol and volume in\[{{m}^{3}}\]. Calculate the unit of ?a'.
What will be the unit of ?a'
when pressure is in atmosphere and volume in \[d{{m}^{3}}\]?
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question_answer64)
Name two phenomena that can be
explained on the basis of surface tension.
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question_answer65)
Viscosity of a liquid arises due
to strong intermolecular forces existing between the molecules. Stronger the intermolecular
forces, greater is the viscosity. Name the intermolecular forces existing in
the following liquids and arrange them in the increasing order of their
viscosities.
Also give reason for the
assigned order in one line.
Water, hexane\[\left( C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}C{{H}_{2}}C{{H}_{2}}C{{H}_{3}}
\right)\], glycerine\[(C{{H}_{2}}OHCH(OH)\,C{{H}_{2}}OH)\]
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question_answer66)
Explain the effect of increasing
the temperature of a liquid, on intermolecular forces operating between its particles,
what will happen to the viscosity of a liquid if its temperature is increased?
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question_answer67)
The variation of pressure with
volume of the gas at different temperatures can be graphically represented as shown
in figure
On the basis of this graph
answer the following questions :
(i) How will the volume of a gas
change if its pressure is increased at constant temperature?
(ii) At a constant pressure, how
will the volume of a gas change if the temperature is increased from 200 K to 400
K?
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question_answer68)
Pressure versus volume graph for
a real gas and an ideal gas are shown in fig. 5.4. Answer the following
questions on the basis of this graph.
(i) Interpret the behaviour of
real gas with respect to ideal gas at low pressure.
(ii) Interpret the behaviour of
real gas with respect to ideal gas at high pressure. States of Matter : Gases
and Liquids
(iii) Mark the pressure and
volume by drawing a line at the point where real gas behaves as an ideal gas.
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question_answer69)
In some of the following
questions, one option of left column may be correlated to more than one option
in the right column.
Match the graphs between the
following variables with their names :
|
Graphs
|
Names
|
|
(i) Pressure vs temperature graph at
constant molar volume
|
(a) Isotherms
|
|
(ii) Pressure vs temperature graph at
constant molar volume
|
(b) Constant
temperature
|
|
(iii) Volume vs temperature graph at
constant pressure
|
(c) Isochores
|
|
|
(d) Isobars
|
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question_answer70)
Match the following gas laws
with the equation representing them :
|
|
Column I
|
|
Column II
|
|
(i)
|
Boyle's
law
|
(a)
|
\[V\propto
n\]constant T and p
|
|
(ii)
|
Charles'
law
|
(b)
|
\[{{p}_{Total}}={{p}_{1}}+{{p}_{2}}+{{p}_{3}}+...\]at
Constant T,V
|
|
(iii)
|
Dalton's
law
|
(c)
|
\[\frac{pV}{T}=\text{Constant}\]
|
|
(iv)
|
Avogadro's
law
|
(d)
|
\[V\propto
T\]at constant n and p
|
|
|
|
(e)
|
\[p\propto \frac{1}{V}\] at constant n and T
|
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question_answer71)
Match the following graphs of
ideal gas with their co-ordinates :
|
Graphical representation
|
x and y co-ordinate
|
(i)
|
(a) \[pV\,vsV\]
|
(ii)
|
(b) \[p\,vs\,V\]
|
(iii)
|
(c) \[p\,vs\,\frac{1}{V}\]
|
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question_answer72)
In the following questions a
statement of Assertion (A) followed by a statement of Reason (R) is given.
Choose the correct option out of the choices given below each question.
(a) Both A and R are true and R
is the correct explanation of A.
(b) Both A and R are true but R
is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Assertion (A): Three
states of matter are the result of balance between intermolecular forces and
thermal energy of the molecules.
Reason (R):
Intermolecular forces tend to keep the molecules together but thermal energy of
molecules tends to keep them apart.
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question_answer73)
Assertion (A): At
constant temperature, pV vs V plot for real gases is not a straight line.
Reason (R): At high
pressure all gases have Z > 1 but at intermediate pressure most gases have Z
< 1.
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question_answer74)
Assertion (A): The
temperature at which vapour pressure of a liquid is equal to the external
pressure is called boiling temperature.
Reason (R): At high
altitude atmospheric pressure is high.
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question_answer75)
Assertion (A): Gases do
not liquefy above their critical temperature, even on applying high pressure.
Reason (R): Above
critical temperature, the molecular speed is high and intermolecular
attractions cannot hold the molecules together because they escape because of high
speed.
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question_answer76)
Assertion (A): At
critical temperature liquid passes into gaseous state imperceptibly and
continuously.
Reason (R): The density
of liquid and gaseous phase is equal at the critical temperature.
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question_answer77)
Assertion (A): Liquids
tend to have maximum number of molecules at their surface.
Reason (R): Small liquid
drops have spherical shape.
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question_answer78)
Isotherms of carbon dioxide at
various temperatures are represented in figure given ahead.
Answer the following questions
based on this figure.
(i) In which state will \[C{{O}_{2}}\]
exist between the points a and bat temperature\[{{T}_{1}}\]?
(ii) At what point will \[C{{O}_{2}}\]start
liquefying when temperature is \[{{T}_{1}}\]?
(iii) At what point will \[C{{O}_{2}}\]
be completely liquefied when temperature is\[{{T}_{2}}\]?
(iv) Will condensation take
place when the temperature is\[{{T}_{3}}\]?
(v) What portion of the isotherm
at represent liquid and gaseous \[C{{O}_{2}}\] at equilibrium?
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question_answer79)
The variation of vapour pressure
of different liquids with temperature is shown in fig. 5.6.
(i) Calculate graphically
boiling points of liquids A and B.
(ii)If we take liquid C in a
closed vessel and heat it continuously. At what temperature will it boil?
(iii) At high altitude,
atmospheric pressure is low (say 60 mm Hg). At what temperature liquid D boils?
(iv) Pressure cooker is used for
cooking food at hill station. Explain in terms of vapour pressure why is it so?
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question_answer80)
Why does the boundary between
liquid phase and gaseous phase disappear on heating a liquid upto critical temperature
in a closed vessel? In this situation what will be the state of the substance?
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question_answer81)
Why does sharp glass edge become
smooth on heating it up to its melting point in a flame? Explain which property
of liquids is responsible for this phenomenon.
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question_answer82)
Explain the term 'laminar flow'. Is the
velocity of molecules same in all the layers in laminar flow? Explain your
answer.
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