CBSE Questions for Class 11 Medical Chemistry States Of Matter Gases And Liquids Quiz 6 - MCQExams.com

$$I$$ is surface molecule whereas $$II$$ is interior molecule. Choose the correct one.
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  • $$I$$ results net attraction into the liquid
  • $$II$$ are attracted in all directions
  • Both $$A$$ and $$B$$
  • None of the above
At high altitudes, water boils at a lower temperature because
  • the atmospheric pressure is high at high altitudes
  • the viscosity of water is reduced at high altitudes
  • the atmospheric pressure is low at high altitudes
  • the surface tension of water is reduced at high altitudes
The correct expression of partial pressure in terms of mole fraction is :
  • $$p_{1} = x_{1}P_{total}, p_{2} = x_{2}P_{total}$$
  • $$p = x_{1}x_{2}P_{total}$$
  • $$P_{total} = p_{1}x_{1}, P_{total} = p_{2}x_{2}$$
  • $$p_{1} + p_{2} = x_{1} + x_{2}$$
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?
  • $$0.8\times 10^{4} atm$$
  • $$0.008\ N\ m^{-2}$$
  • $$8\times 10^{4} N\ m^{-2}$$
  • $$0.25\ atm$$
Dipole-dipole forces act between the molecules possessing permanent dipole. Ends of dipoles possess 'partial charges'. The partial charge is:
  • more than unit electronic charge
  • equal to unit electronic charge
  • less than unit electronic charge
  • double the unit electronic charge
According to kinetic theory of gases, the collisions between molecules of a gas:
  • occur in a zig-zag path
  • occur in a straight line
  • change velocity and energy
  • result in settling down of molecules
Liquids are similar to gases because:
  • both possess the property of flowing and take the volume of the containers
  • both diffuse and take the shape of the containers
  • both are readily compressible and diffuse
  • both are capable of infinite expansion
Which of the following assumptions is incorrect according to kinetic theory of gases?
  • Particles of a gas move in all possible directions in straight lines
  • All the particles, at any particular time, have same speed and same kinetic energy
  • There is no force of attraction between the particles of a gas at ordinary temperature and pressure
  • The actual volume of the gas is negligible in comparison to the empty space between them
Kinetic energy of a gas depends upon its:
  • Molecular mass
  • Atomic mass
  • Equivalent mass
  • None of these
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?
  • Increases
  • Decreases
  • Remains same
  • Becomes half
'Equal volumes of all gases at the same temperature and pressure contain equal number of molecules'. This law is called as
  • Boyle's law
  • Charle's law
  • Avogadro's law
  • Gay Lussac's law
The kinetic theory of matter helped a great deal in understanding the behaviour of gases. Which of the following statements did not belong to it?
  • When the gas is heated by raising its temperature the molecules move faster
  • The molecules in a gas are always moving
  • Gases are made up of small particles called molecules
  • When molecules collide, they lose energy
Which of the following is correct?
  • Van der waals radius of chlorine is bigger than nitrogen.
  • Covalent radius of nitrogen is bigger than chlorine.
  • Van der waals radius of chlorine is smaller than nitrogen.
  • All are correct.
Which scientist discovered that the same amount of space was occupied by equal numbers of molecules of gases, irrespective of whether it was hydrogen or chlorine or fluorine?
  • Gay-Lussac
  • Avogadro
  • Marconi
  • Wohler
Among the following substances, the lowest vapour pressure is exerted by:
  • water
  • alcohol
  • ether
  • mercury
Atmospheric pressures recorded in different cities are as follows:

CitiesShimlaBangaloreDelhiMumbai
$$p$$ 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.
  • Shimla
  • Bangalore
  • Delhi
  • Mumbai
$$3$$ moles of $$P$$ and $$2$$ moles of $$Q$$ are mixed, what will be their total vapour pressure in the solution if their partial vapour pressures are $$80$$ and $$60$$ torr respectively?
  • $$80$$ torr
  • $$140$$ torr
  • $$72$$ torr
  • $$70$$ torr
The vapour pressure of a solvent at $$293$$K is $$100$$ mm Hg. Then the vapour pressure of a solution containing $$1$$ mole of a strong electrolyte $$(AB_2)$$ in $$99$$ moles of the solvent at $$293$$ K is:
(Assume complete dissociation of solute)
  • $$103$$ mm Hg
  • $$99$$ mm Hg
  • $$97$$ mm Hg
  • $$101$$ mm Hg
According to Avogadro's hypothesis, equal volumes of gases under the same conditions of temperature and pressure will contain:
  • the same number of molecules
  • different number of molecules
  • the same number of molecules only if their molecular masses are equal
  • the same number of molecules if their densities are equal.
What percent of a sample of nitrogen must be allowed to escape if its temperature, pressure and volume are to be changed from $$22{ 0 }^{ 0 }$$C,3atm and 1.65 liter to $$11{ 0 }^{ 0 }$$C,0.7atm and 1.0 liter respectively?
  • 81.8%
  • 71.8%
  • 76.8%
  • 86.8%
Find the lifting power of a $$100$$ litre balloon filled with $$He$$ at $$730\ mm$$ and $$25^oC$$. 
(Density of air $$=1.25\ g/L$$).
  • $$125.23g$$
  • $$95.28g$$
  • $$109.28g$$
  • $$104g$$
If the absolute temperature of a gas is doubled and the pressure is reduced to one-half, the volume of the gas will
  • remain unchanged
  • be doubled
  • increase four-fold
  • be reduced to $$1/4th$$
An ideal solution has equal mol-fractions of two volatile components A and B in the vapour above the solution, the mol-fractions of A and B.
  • are both $$0.50$$
  • are equal but necessarily $$0.50$$
  • are not very likely to be equal
  • are $$1.00$$ and $$0.00$$ respectively
Which of the following has maximum vapour pressure at a given temperature?
Two liquids X and Y form an ideal solution. At $$300$$K, vapour pressure of the solution containing $$1$$ mol of X and $$3$$ mol of Y is $$550$$ mm Hg. At the same temperature, if $$1$$ mol of Y is further added to this solution, vapour pressure of the solution increases by $$10$$ mmHg. Vapour pressure (in mm Hg) of X and Y in their pure states will be ________ respectively.
  • $$200$$ and $$300$$
  • $$300$$ and $$400$$
  • $$400$$ and $$600$$
  • $$500$$ and $$600$$
If you are given Avogadro's number of atoms of a gas $$X$$. If half of the atoms are converted into $$X_{(g)}^+$$ by energy $$\Delta H$$. The IE of $$X$$ is :
  • $$\dfrac{2\Delta H}{N_A}$$
  • $$\dfrac{2N_A}{\Delta H}$$
  • $$\dfrac{\Delta H}{2N_A}$$
  • $$\dfrac{N_A}{\Delta H}$$
A solution at $$20^o$$C is composed of $$1.5$$ mol of benzene and $$3.5$$ mol of toluene. If the vapour pressure of pure benzene of pure benzene and pure toluene at this temperature are $$74.7$$ torr and $$22.3$$ torr. respectively, then the total vapour pressure of the solution and the benzene mole fraction in equilibrium with it will be, respectively.
  • $$38.0$$ torr and $$0.589$$
  • $$30.5$$ torr and $$0.389$$
  • $$35.8$$ torr and $$0.280$$
  • $$35.0$$ torr and $$0.480$$
Under the same conditions how many $$ml$$ of $$1\ M$$ $$KOH$$ and $$0.5\ M\ H_2SO_4$$ solutions, respectively, when mixed to form a total volume of $$100\ mL$$ produce the highest rise in temperature?
  • $$67, 33$$
  • $$33, 67$$
  • $$40, 60$$
  • $$50, 50$$
What is the density of wet air with $$75\%$$ relative humidity at $$1$$ atm and $$300$$ K? 
[Given: vapour pressure of $$H_2O$$ is $$30$$ torr and average molar mass of air is $$29$$g $$mol^{-1}$$]
  • $$1.614$$ g/L
  • $$0.96$$ g/L
  • $$1.06$$ g/L
  • $$1.164$$ g/L
Which of the following statements is/are wrong?
  • At a given temperature the transitional K.E. of one mole of every gas is same which is equal to $$3/2$$ RT
  • K.E. of a gas depends on its mass
  • K.E. depends on the volume
  • K.E. depends on the pressure
Under $$3$$ atm, $$12.5$$ litre of a gas weighs $$15$$ gm. What will be the average speed of gaseous molecules?
  • $$8.028\times 10^4$$ cm/sec
  • $$6.028\times 10^2$$ cm/sec
  • $$8.028\times 10^5$$ cm/sec
  • $$6.028\times 10^4$$ cm/sec

Read the Paragraph carefully and answer the following questions:

 100 g of an ideal $$\left( {mol.wt. = 40} \right)$$ gas  is present in a cylinder at $${27^0}c\;and\,2atm$$  pressure. During transportation, cylinder fell and a dent was developed in the cylinder. The valve attached to cylinder cannot keep the pressure greater than $$2atm$$ and therefore  $$'10g'$$ of gas leaked-out through cylinder.

The volume of the cylinder before a dent was:
  • $$10.79litre$$
  • $$20.79litre$$
  • $$30.79litre$$
  • $$40.79litre$$
A $$3.00\ L$$ oxygen gas is collected over water at $${27}^{o}C$$ when the barometric pressure is $$787\ Torr$$. If vapour pressure of water is $$27\ Torr$$ at $${27}^{o}C$$, moles of $$O_{2}$$ gas will be?
  • $$0.122$$
  • $$0.126$$
  • $$0.004$$
  • $$0.152$$
A glass container is sealed with a gas at $$0.800$$ atm pressure and at $$25^o$$C. The glass container sustain pressure of $$2$$ atm. Calculate the temperature to which gas can be heated before bursting the container.
  • $$432^o$$C.
  • $$472^o$$C.
  • $$372^o$$C.
  • $$572^o$$C.
A sample of water gas contains $$42\%$$ by volume of carbon monoxide. If the total pressure is $$760$$ mm of Hg, the partial pressure of carbon monoxide is :
  • $$380$$ mm of Hg
  • $$319.2$$ mm of Hg
  • $$38$$ mm of Hg
  • $$360$$ mm of Hg
The vapour pressure of two liquids $$P$$ and $$Q$$ are $$80$$ torr and $$60$$ torr respectively. The total vapour pressure obtained by mixing $$3$$ mole of P and $$2$$ mole of $$Q$$ would be:
  • $$68$$ torr
  • $$20$$ torr
  • $$140$$ torr
  • $$72$$ torr
At what relative humidity will $$Na_2SO_4$$ be deliquescent (absorb moisture) when exposed to the air at $$0^o$$C? 
Given: $$Na_2SO_4\cdot 10H_2O(s)\rightleftharpoons Na_2SO_4(s)+10H_2O(g); K_p=4.08\times 10^{-25}$$ and vapour pressure of water $$0^o$$C $$=4.58$$ Torr.
  • Below $$50.5\%$$ but Above $$30.5\%$$
  • Above $$50.5\%$$ 
  • Above $$30.5\%$$
  • Below $$30.5\%$$
Assume centre of sun to consist of gases whose average molecular weight isThe density and pressure of the gas are $$1.3g{ cc }^{ -1 }$$ and $$1.12\times { 10 }^{ 9 }$$ atm respectively. The temperature of sun is:
  • $$2\times { 10 }^{ 3 }K$$
  • $$2\times { 10 }^{ 5 }K$$
  • $$2\times { 10 }^{ 7 }K$$
  • $$2\times { 10 }^{ 9 }K$$
Select correct statement(s) :
  • Kinetic energy is zero at $${ O }^{ 0 }$$C
  • RMS velocity of $${ O }_{ 2 }$$ at $${ 27 }^{ 0 }$$C is =$$\sqrt { \frac { 3\times 8.314\times 300 }{ 32 } } { ms }^{ -1 }$$
  • Distribution of molecules is very small when $$u\rightarrow O\quad or\quad u\rightarrow \infty $$
  • All the statement are correct
The vapour pressure of two pure liquids $$(A)$$ and $$(B)$$ are $$100$$ and $$80\ torr$$ respectively. The total vapour pressure of solution obtained by mixing $$2$$ moles of $$(A)$$ and $$3$$ moles of $$(B)$$ would be :-
  • $$120\ torr$$
  • $$36\ torr$$
  • $$88\ torr$$
  • $$180\ torr$$
A closed bulb capacity 200ml containing $${ CH }_{ 4 }$$, $${ H }_{ 2 }$$ and He at 300K. The ratio of partial pressure of $${ CH }_{ 4 }$$, $${ H }_{ 2 }$$ and He, respectively is 2:3:Calculate the ratio of their weights present in the container.
  • 2:4:6
  • 16:8:100
  • 16:3:10
  • 4:9:25
Ideal gas equation is also called equation of states because:
  • it depends on states of matter
  • it is relation between four variables and describes the state of any gas
  • it is combination of various gas laws and any variable can be calculated
  • none of these
To expel half the mass of air from a large flask at $${ 27 }^{ 0 }C$$, it must be heated to:
  • $$54^{ 0 }C$$
  • $$177^{ 0 }C$$
  • $$277^{ 0 }C$$
  • $$327^{ 0 }C$$
The elements which normally exist in the liquid state are :
  • Bromine and iodine
  • Mercury and chlorine
  • iodine and mercury
  • Bromine and mercury
Volume of an object is $$20$$ $$cm^3$$ and the mass in $$50$$g. Density of water is $$1$$ g$$cm^{-3}$$. Does the object float on water?
  • True
  • False
If 2 moles of A and 3 moles of B are mixed to form an ideal solution vapour pressure of A and B are 120 and 180 mm of Hg respectively. then the composition of A and B in the Vapour phase when the first traces of vapour are formed in the above case is:
  • $$X^l A = 0.407$$
  • $$X^l A = 0.8$$
  • $$X^l A = 0.109$$
  • $$X^l A = 0.307$$
The density of a gas is equal to: 
($$P =$$ pressure, $$V=$$ volume, $$T=$$ temperature, $$R=$$ gas constant, $$n=$$ number of moles and $$M=$$ molecular weight).
  • $$nP$$
  • $$\dfrac{PM_w}{RT}$$
  • $$\dfrac{P}{RT}$$
  • $$\dfrac{M_w}{V}$$
The vapour pressure of a pure liquid A is $$70$$ torr at $$27^o$$C. It forms an ideal solution with another liquid B. The mole fraction of B is $$0.2$$ and total vapour pressure of the solution is $$84$$ torr at $$27^o$$C. The vapour pressure of pure liquid B at $$27^o$$C.
  • $$14$$
  • $$56$$
  • $$140$$
  • $$70$$
Equal masses of $$SO_2, CH_4$$ and $$O_2$$ are mixed in empty container at $$298$$K, where total pressure is $$2.1$$ atm. The partial pressures of $$CH_4$$ in the mixture is:
  • $$0.5$$ atm
  • $$0.75$$ atm
  • $$1.2$$ atm
  • $$0.6$$ atm
Which system contains molecules with the same average kinetic energy as the molecules in $$10.0$$g of carbon dioxide at $$10^o$$C?
  • $$10$$g of $$CO_2$$ at $$40^o$$C
  • $$20$$g of $$CO_2$$ at $$20^o$$C
  • $$20$$g of $$CO_2$$ at $$5^o$$C
  • $$40$$g of $$CO_2$$ at $$10^o$$C
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