CBSE Questions for Class 11 Medical Chemistry States Of Matter Gases And Liquids Quiz 8 - MCQExams.com

$${ \Delta  }_{ f }{ G }^{ o }$$ at $$500\ K$$ for substance $$S$$ in liquid state and gaseous state are $$ +100.7\ kcal\ { mol }^{ -1 }$$ and $$ +103\ kcal\ { mol }^{ -1 }$$ respectively. Vapour pressure of liquid $$S$$ at $$500\ K$$ is approximately equal to: $$(R= 2\ { cal }\ K^{ -1 }\ { mol }^{ -1 })$$
  • $$0.1\ atm$$
  • $$1\ atm$$
  • $$10\ atm$$
  • $$100\ atm$$
The density of a gas is $$2.5$$g/L at $$127^0$$ C and $$1$$ atm. The molecular weight of the gas is:
  • $$82.1$$
  • $$41.05$$
  • $$56$$
  • $$28$$
A solution has a $$1:4$$ mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at $$20^{\circ}C$$ are $$440$$ mm of $$Hg$$ for pentane and $$120$$ mm of $$Hg$$ for hexane. The mole fraction of pentane in the vapour phase would be?
  • $$0.549$$
  • $$0.200$$
  • $$0.786$$
  • $$0.478$$
An ideal gas obeying kinetic gas equation :
  • can be liquefied if its temperature is more than critical temperature
  • can be liquefied at any value of any value T and P
  • can not be liquefied under any value of T and P
  • can be liquefied if its pressure is more than critical pressure
The vapour pressure of pure $$A$$ is $$10$$ torr and at the same temperature when $$1\ g$$ of $$B$$ is dissolved in $$20\ gm$$ of $$A$$, its vapour pressure is reduced to $$9.0$$ torr. If the molecular mass of $$A$$ is $$200$$ amu, then the molecular mass of $$B$$ is:
  • $$100\ amu$$
  • $$90\ amu$$
  • $$75\ amu$$
  • $$120\ amu$$
The vapour pressure of a solvent decreased by 10 mm of mercury when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.What should be the mole fraction of the solvent if the decrease in the vapour pressure is to be 20 mm of mercury?
  • 0.4
  • 0.6
  • 0.8
  • 0.2
A balloon filled with methane $$CH_4$$ is pricked with a sharp point and quickly plunged into a tank of hydrogen at the same pressure. After sometime the balloon will have?
  • Enlarged
  • Collapsed
  • Remained unchanged in size
  • Ethylene $$(C_2H_4)$$ inside it
A gas occupies $$600ml$$ at $${27}^{o}C$$ and $$730mm$$ pressure. What would be its volume at STP?
  • $$0.5244$$ lit.
  • $$1.5244$$ lit.
  • $$2.5244$$ lit
  • $$3.5244$$ lit
With increase in temperature, the fluidity of liquids 
  • increases
  • decreases
  • remains constant
  • may increase or decrease
The volume of helium gas is 44.8 L at:
  • 100$$^oC$$ and 1 atm
  • 0 $$^o C$$ and 1 atm
  • 0 $$^o \ C$$ and 0.5 atm
  • 100 $$^o \ C$$ and 0.5 atm
Equal weights of $$HF$$, $$HCl$$ ,$$HBr$$ , and $$HI$$ $${at\ 87}^{0}C$$ and $$750\ mm$$ $$Hg$$ pressure are taken. The correct sequence of these gases in the increasing order of their volume is ?
  •  HI<HBr<HCl<HF
  •  HBr<HI<HCl<HF
  •  HF<HBr<HCl<HI
  •  HI<HBr<HF<HCl
If the pressure and absolute temperature of $$2\ liters$$ of carbon dioxide are doubled the volume of the gas would  be: 
  • $$2\ litres$$
  • $$4\ litres$$
  • $$5\ litres$$
  • $$7\ litres$$
According to Avogadro's law the volume of a gas will ____ as _____ if ____ are held constant.
  • increases, number of moles; P & T
  • decreases, number of moles; P & T
  • increases; T & P; number of moles
  • decreases; P & T; number of moles
Vapour pressure of pure benzene is 119 torr and of toluene is 37.0 torr at the same temperature mole fraction of toluene in vapour phase which is in equilibrium with a solution of benzene and toluene having a mole fraction of toluene 0.50, will be:
  • $$0.137$$
  • $$0.205$$
  • $$0.237$$
  • $$0.435$$

In atmosphere which gas have high partial pressure?
  • $${ N }_{ 2 }$$
  • $${ O }_{ 2 }$$
  • $${ H }_{ 2 }O$$
  • $${ CO }_{ 2 }$$
0.5 mole of each of $$H, \  SO_2$$ and $$CH_4$$, are kept in a container. A hole was made in the container. After 3 hours, the order of partial pressures in the container will be:
  • $$P(CH_{4}) > P(SO_{2}) > P(H_{2})$$
  • $$P(H_{2}) > P(CH_{4}) > P(SO_{2})$$
  • $$P(SO_{2}) > P(CH_{4}) > P(H_{2})$$
  • $$P(H_{2}) > P(SO_{2}) > P(CH_{4})$$
A mixture of ethanol and propanol has vapor pressure 279 mm of Hg at 300 K. The mol fraction of ethanol in the solution is 0.6 and vapour pressure of pure propanol is 210 mm of Hg. Vapour pressure of pure ethanol will be:
  • $$336.6$$ mm
  • $$325$$ mm
  • $$375$$ mm
  • $$415$$ mm
Vapours of a liquid can exist only at ?
  • below boiling point
  • below critical temperature
  • below inversion temperature
  • above critical temperature
The molecular weight of a gas isAt 400K, if 120g of this gas has a volume of 20 litres, the pressure of the gas is?
  • 5.02 atm
  • 0.546 atm
  • 4.92 atm
  • 49.6 atm
A mixture of ethyl alcohol and propyl alcohol has vapour pressure of $$290mm$$ at $$300K$$. The vapour pressure of propyl alcohol is $$200mm$$. If mole fraction of ethyl alcohol is $$0.6$$ its vapour presssure at same temperature will be:-
  • $$360$$
  • $$350$$
  • $$300$$
  • $$700$$
The value of the molar gas constant is:
  • $$8.3145\times 10^3 \ J\ mol^{-1}K^{-1}$$
  • $$1.987 \ cal\ mol^{-1} K^{-1}$$
  • $$0.083145\times 10^3dm^3 bar\ mol^{-1}K^{-1}$$
  • $$0.983145\ dm^3\ bar\ mol^{-1}K^{-1}$$
The amount of solute (mol mass=$$60$$) that must be added to $$180g$$ of water so that the vapour pressure of water is lowered by $$10 \%$$ is?
  • $$30$$g
  • $$60$$g
  • $$120$$g
  • $$12$$g
Equal mass which of the following substance of occupy maximum volume at room temperature? 
  • Sugar
  • Water
  • Oxygen
  • Graphite
The type of molecular force of attraction present in the following compound is :
1818022_88b5187a8a9b42eba73d138b05d6eea1.PNG
  • Intermolecular H-bonding
  • Intramolecular H-bonding
  • van der WaaLs' force
  • All of these
The vapour pressure of a pure liquid A is 70 torr at 300 K. It forms an ideal solution with another liquid B. The mole fraction of B in the solution is 0.2 and total pressure of solution is 84 torr at 300 K. The vapour pressure of pure liquid B at 27C is ?
  • 0.14 torr
  • 560 torr
  • 140 torr
  • 70 torr
The boiling point of $$ C_{6}H_{6},CH_{3}OH, C_{6}H_{5}NH_{2} $$ and $$C_{6}H_{5}NO_{2}   $$ are $$ 80^{\circ},\ 65 ^{\circ},\ 184^{\circ}$$ and $$212^{\circ} $$ respectively. Which will show highest vapourr pressure at room temperature?
  • $$ C_{6}H_{6}$$
  • $$ CH_{3}OH$$
  • $$ C_{6}H_{5}NH_{2} $$
  • $$C_{6}H_{5}NO_{2} $$
A glass tube of volume 112ml containing a gas is partially evacuated till the pressure in it drops to $$3.8\times { 10 }^{ -5 }$$ torr at 0 degree C.The number of molecules of the gas remaining in the tube?
  • $$3\times { 10 }^{ 17 }$$
  • $$1.5\times { 10 }^{ 14 }$$
  • $$112.5\times { 10 }^{ 20}$$
  • Name of the gas is required
One mole of non volatile solute is dissolved in two moles of water. The vapour pressure of the solution relative to that of water is:
  • $$\dfrac{2}{3}$$
  • $$\dfrac{1}{3}$$
  • $$\dfrac{1}{2}$$
  • $$\dfrac{3}{1}$$
Which of the following exists as a liquid at room temperature due to the formation of associated molecules only?
  • Benzene
  • Ammonia
  • Bromine
  • Carbon disulphide
If $$P^o$$ and $$P^s$$ are the vapour pressure of the solvent and solution respectively. $$n_ 1$$ and $$n_2$$ are the mole fraction of the solvent and solute respectively, then?
  • $$P^S=P^o n_1$$
  • $$P^S=P^o n_2$$
  • $$P^o=P^S n_2$$
  • $$P^S=P^o \dfrac { { n }_{ 1 } }{ { n }_{ 2 } } $$
Vapour pressure diagram of some liquids plotted against temperature are shown below most volatile liquid is 

1131766_5e693d4bb6bb47718b02f7adcd0b89d2.png
  • $$A$$
  • $$B$$
  • $$C$$
  • $$D$$
Two liquids, A and B, form an ideal solution. At the specified temperature, the vapour pressure of pure A is 200 mm Hg while that of pure B is 75 mm Hg. If the vapour over the mixture consists of 50 mol percent A, what is the mole percent A in the liquid?
  • 20
  • 76
  • 27
  • 65
The relative decrease in vapour pressure of an aqua solution containing 2 moles of $$4NaCl$$ in 3 moles of $${H}2_{O}$$ is 0.On reaction with $$AgNO_3$$ this solution will form:
  • 1 mol of $$AgCl$$
  • 0.25 mol of $$AgCl$$
  • 2 mol of $$AgCl$$
  • 0.4 mol of $$AgCl$$
The vapour pressure of water is $$12.3k \, Pa$$ at $$300K$$. Calculate the vapour pressure $$1$$ molal solution of a non-volatile solute in it.
  • $$12.08 \ kPa$$
  • $$1.208 \ Ppa$$
  • $$2.4 \ kPa$$
  • $$0.4 kPa$$
Two liquids A and B have $${P}_{A}^{o}$$ and $${P}_{B}^{o}$$ in the ratio $$1:3$$ and the ratio of number of moles of $$A$$ and $$B$$ in liquid phase are $$1:3$$. Then mole fraction of A in vapour phase in equilibrium with the solution is equal to:
  • $$0.1$$
  • $$0.2$$
  • $$0.5$$
  • $$1.0$$
$$4.4gm$$ of a gas at STP occupies a volume of $$2.24$$ lit the gas can be:
  • $${O}_{2}$$
  • $$CO$$
  • $${NO}_{2}$$
  • $${CO}_{2}$$
In an experiment during the analysis of a carbon compound, $$145\ cc$$ of $${H}_{2}$$ was collected at $$760\ mm$$ of Hg pressure and $${27}^{o}\ C$$ temperature. The mass of $${H}_{2}$$ is nearly:
  • $$10\ mg$$
  • $$12\ mg$$
  • $$24\ mg$$
  • $$6\ mg$$
Normal boiling point of a liquid is that temperature at which vapour of the liquid pressure of the liquid is equal to:
  • zero
  • 380mm of Hg
  • 760mm of Hg
  • 100mm of Hg
For gaseous state, if most probable speed is denoted by $${C}^{\ast}$$, average speed by $$\overline { C } $$ and mean square speed by $$C$$, then for a large number of molecules the ratios of these speeds are:
  • $${C}^{\ast}:\overline { C } :C=1.225:1.128:1$$
  • $${C}^{\ast}:\overline { C } :C=1.128:1.225:1$$
  • $${C}^{\ast}:\overline { C } :C=1:1.128:1.225$$
  • $${C}^{\ast}:\overline { C } :C=1:1.225:1.128$$
Correct gas equation is :
  • $$\dfrac{V_1T_2}{P_!}=\dfrac{V_2T_1}{P_2}$$
  • $$\dfrac{P_1V_1}{P_2V_2}=\dfrac{T_1}{T_2}$$
  • $$\dfrac{P_1T_2}{V_1}=\dfrac{P_2V_2}{T_2}$$
  • $$\dfrac{V_1V_2}{T_1T_2}=P_1P_2$$
Pure hydrogen sulphide is stored in a tank of $$100$$ litre capacity at $${20^0}C$$ and $$2$$ atm pressure . The mass of the gas will be:
  • $$34$$
  • $$340$$ g
  • $$282.68$$ g
  • $$28.24$$ g
A relation between vapour pressure and the temperature is known as
  • Ideal gas equation
  • Boltzman equation
  • Clausious equation
  • Clausius-Clapeyron equation
 Equal weight of $${CH}_{4}$$ and $${H}_{2}$$ are mixed in a container at $$25^o C$$, the fraction of total pressure exerted by hydrogen is :
  • $$\cfrac { 1 }{ 2 }$$
  • $$\cfrac { 1 }{ 3 }$$
  • $$\cfrac { 1 }{ 9 }$$
  • $$\cfrac { 8 }{ 9 }$$
Lowering in vapour pressure is highest for:
  • $$0.2m$$ urea
  • $$0.1m $$ glucose
  • $$0.1m \, MgSO_4$$
  • $$0.1m \, BaCl_2$$
The total kinetic energy (in joules) of the molecules in $$8 \ g$$ of methane at $$27^oC$$ is:
  • $$374100 \ J$$
  • $$935.3 \ J$$
  • $$1870.65 \ J$$
  • $$700 \ J$$
if the mass ratio of hydrogen gas is to oxygen gas in a mixture is 1:2 then the ratio of their number of molecules is:
  • 4:1
  • 1:2
  • 8:1
  • 1:4
Mass of a given gas occupies two litre at STP. By keeping the pressure constant, at what temperature the gas will occupy 4 litre?
  • $$ 546\ K $$
  • $$ 273\ K $$
  • $$ 100^oC $$
  • $$ 50^oC $$
In an ideal solution of non-volatile solute B in solvent A in 2: 5 molar ratio has vapour pressure 250 mm. If another solution in ratio 3: 4 prepared then vapour pressure above this solution is:
  • 200 mm
  • 250 mm
  • 350 mm
  • 400 mm
The relative lowering of vapour pressure of a solution containing $$6\ g$$ of urea dissloved in $$90\ g$$ of water is
  • $$0.0196$$
  • $$0.05$$
  • $$1.50$$
  • $$0.01$$
A sample of 16g charcoal was brought into contact with $$  C{  H}_{  4}$$ gas contained in a vessel of 1 litre at $$ 2{ 7 }^{0  }C  $$ . The pressure of gas was found to fall from 760 to 608 torr. The density of charcoal sample is 1.6g/ $$ c{  m}^{ 3 }  $$. What is the volume of the $$  C{  H}_{  4}$$ gas adsorbed per gram of the adsorbent at 608 torr and $$ 2{ 7 }^{0  }C  $$ ?
  • 125 mL/g
  • 16.25 mL/g
  • 26 mL/g
  • None of these
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