CBSE Questions for Class 11 Medical Chemistry States Of Matter Gases And Liquids Quiz 12 - MCQExams.com

What is the composition of last deoplet of liquid remaining in equilibrium with vapour?
  • $$x_A = 0.6; x_B = 0.4$$
  • $$x_A = 0.5; x_B = 0.5$$
  • $$x_A = 0.7; x_B = 0.3$$
  • $$x_A = 0.3; x_B = 0.7$$
Vapour pressure of a pure liquid $$X$$ is $$2$$ atm at $$300$$K. It is lowered to $$1$$ atm on dissolving $$1$$g of $$Y$$ in $$20$$g of liquid $$X$$. If molar mass of $$X$$ is $$200$$, what is the molar mass of $$Y$$?
  • $$20$$
  • $$10$$
  • $$100$$
  • $$30$$
Two liquids X and Y form an ideal solution.
The mixture has a vapour pressure of 400mm at 300K, when mixed in the molar ratio of 1:1 and a vapour pressure of 350mm when mixed in the molar ratio of 1:2 at the same temperature. The vapour pressures of the two pure liquids X and Y respectively are?
  • 250mm, 550mm
  • 350mm, 450mm
  • 350mm, 700mm
  • 550mm, 250mm
What is the total pressure exerted by the mixture of 7.0 g of $$N_2$$, 2g of hydrogen and 8.0 g of sulphur dioxide gases in a vessel of 6.1L capacity that has been kept in a reservoir at $$27^oC$$?
  • 2,5 bar
  • 4.5 bar
  • 10 atm
  • 5.7 bar
Equal weights of methane and hydrogen are mixed in an empty container at $${25}^{o}C$$. The fraction of the total pressure exerted by hydrogen is:
  • $$\cfrac{1}{2}$$
  • $$\cfrac{8}{9}$$
  • $$\cfrac{1}{9}$$
  • $$\cfrac{16}{17}$$
If $$Fc$$ and $$Fa$$ denote cohesive and adhesive force on a liquid molecule near the surface of a solid. then the surface of request is concave , when;
  • $$ F_{A}<\frac{F_{0}}{\sqrt{2}} $$
  • $$ F_{A}=\frac{F_{c}}{\sqrt{2}} $$
  • $$ F_{n}>\frac{F_{c}}{\sqrt{2}} $$
  • $$ F_{A}>F_{C} $$
For the two compounds, the vapour pressure of (2) at a particular temperature is expected to be:-
1070517_78a30913154143e5bb45bbc66e4cf859.PNG
  • Higher than (i)
  • Lower than that of (i)
  • Same as that of (i)
  • Can be 'higher or lower depending upon the size of the vessel
A $$4.40\ g$$ piece of solid $$CO_{2}$$ is allowed to sublime in a balloon. The final volume of the balloon is $$1.00L$$ at $$300K$$. What is the pressure of the gas?
  • $$0.122$$
  • $$122$$
  • $$2.46$$
  • $$24.6$$
$${N}_{2}+3{H}_{2}\rightleftharpoons 2{NH}_{3}$$. Starting with one mole of nitrogen and $$3$$ moles of hydrogen, at equilibrium $$50$$% of each had reacted. If the equilibrium pressure is $$P$$, the partial pressure of hydrogen at equilibrium would be:
  • $$P/2$$
  • $$P/3$$
  • $$P/4$$
  • $$P/6$$
Select correct option(s).
1067195_8165ee896a8e4042b099a06be26e921c.png
  • Pressure in container $$-I$$ is $$3\ atm$$ before opening the valve
  • Pressure after opening the valves is $$3.57\ atm$$
  • Moles in each compartment are same after opening the valve
  • Pressure in each compartment are same after opening the valve
The total pressure for volatile components $$A$$ and $$B$$ is 0.02 bar at equilbibrium. If the mole fractions of component $$A$$ is $$0.2$$, then what will be partial pressure of compount $$B$$?
  • $$0.02\ bar$$
  • $$0.04\ bar$$
  • $$0.016\ bar$$
  • $$0.2\ bar$$
A $$2.24 L$$ cylinder of oxygen at $$1atm$$ and $$273 K$$ is found to develop a leakage. When the leakage was plugged the pressure dropped to $$570 mm$$ of Hg. The number of moles of gas that escaped will be:
  • $$0.025$$
  • $$0.050$$
  • $$0.075$$
  • $$0.09$$
The density of a gas $$A$$ is twice that of $$B$$. Molar mass of $$A$$ is half that of $$B$$. The ratio of partial pressure of $$A$$ to $$B$$ is:
  • $$1/4$$
  • $$1/2$$
  • $$4/1$$
  • $$2/1$$
At $${100}^{o}C$$ and $$1$$ atm, if the density of liquid water is $$1.0g$$ $${cm}^{-3}$$ and that of water vapour is $$0.0006g$$ $${cm}^{-3}$$, then the volume occupied by water molecules in $$1$$ litre of steam at that temperature is:
  • $$6{cm}^{3}$$
  • $$60{cm}^{3}$$
  • $$0.6{cm}^{3}$$
  • $$0.06{cm}^{3}$$
$$100\space g$$ of liquid $$A$$(molar mass $$140\space g { mol }^{ -1 })$$ was dissolved in $$1000\space g$$ of liquid $$B$$ (molar mass $$180 \space g { mol }^{ -1 })$$. The vapour pressure of pure liquid $$B$$ was found to be $$500 \space torr.$$ Calculate the vapour of pure liquid $$A$$ and its vapour pressure in the solution if the total vapour pressure of the solution is $$475 \space torr$$.
  • $$22\space torr$$
  • $$32\space torr$$
  • $$45 \space torr$$
  • $$36 \space torr$$
A $$1.00L$$ vessel containing $$1.00g$$ $${H}_{2}$$ gas at $${27}^{o}C$$ is connected to a $$2.00L$$ vessel containg $$88.0g$$ $${CO}_{2}$$ gas, at also $${27}^{o}C$$. When the gases are completely mixed, total pressure is?
  • $$20.525$$ atm
  • $$4.105$$ atm
  • $$16.420$$ atm
  • $$730.69$$ atm
In a gaseous mixture at $${20}^{o}C$$ the partial pressure of the components are
$${H}_{2}:150$$ Torr  $${CH}_{4}:300$$ Torr
$${CO}_{2}:200$$ Torr  $${C}_{2}{H}_{4}:100$$ Torr
Volume percent of $${H}_{2}$$ is:
  • $$26.67$$
  • $$73.33$$
  • $$80.00$$
  • $$20$$
A $$1.0\ g$$ sample of air consists of approximately $$0.76\ g$$ of nitrogen and $$0.24\ g$$ of oxygen. This sample occupies a $$1.0\ L$$ vessel at $$20^{o}C$$. Then:
  • The partial pressure of $$N_{2}$$ is $$0.65\ atm$$
  • The partial pressure of $$O_{2}$$ is $$0.36\ atm$$
  • The total pressure is $$0.83\ atm$$
  • The total pressure is $$1.05\ atm$$
$$0.5\ \text{mole}$$ of each $$H_{2},SO_{2}$$ and $$CH_{4}$$ are kept in a container. A hole was made in the container. After 3 hours, decreasing order of partial pressures of gases in the container will be:
  • $$P_{SO_{2}} > P_{CH_{4}} > P_{H_{2}}$$
  • $$P_{H_{2}} > P_{SO_{2}} > P_{CH_{4}}$$
  • $$P_{CH_{4}} > P_{SO_{4}} > P_{H_{2}}$$
  • $$P_{CH_{4}} > P_{H_{2}} > P_{SO_{2}}$$
The value of $${K}_{p}$$ for the reaction
$${CO}_{(2(g)}+{C}_{(g)}\rightleftharpoons 2{CO}_{(g)}$$ is $$3.0$$ at $$1000K$$. If initially $${P}_{{CO}_{2}}=0.48$$ bar and$${P}_{CO}=0$$ bar and pure graphite is present. The equilibrium partial pressure of $$CO$$ and $${CO}_{2}$$ are:
  • $${P}_{CO}=0.33,{P}_{{CO}_{2}}=0.15$$
  • $${P}_{CO}=0.66,{P}_{{CO}_{2}}=0.33$$
  • $${P}_{CO}=1.44,{P}_{{CO}_{2}}=0.66$$
  • $${P}_{CO}=0.66,{P}_{{CO}_{2}}=0.15$$
$$N_{2}$$ is found in a litre flask under $$100\ kPa$$ pressure and $$O_{2}$$ is found in another $$3$$ litre flask under $$320\ kPa$$ pressure. If the two flask are connected, the resultant pressure is:
  • $$265\ kPa$$
  • $$210\ kPa$$
  • $$420\ kPa$$
  • $$365\ kPa$$

$$18.0\ g$$ of glucose$$\left( {{C_6}{H_{12}}{O_6}} \right)$$ is added to $$178.2\ g$$ of water. The vapour pressure of water for this aqueous solution at $${100^o}\ C$$ is :
  • $$759..00$$ Torr
  • $$7.60$$ Torr
  • $$76.00$$ Torr
  • $$752.40$$ Torr
Factors affecting the rate of diffusion are:
I. Gradient of concentration 
II. Permeability of the membrane
III. Temperature
IV. Pressure
V. Size of diffusing material
  • I, III and V are correct
  • I and V are correct
  • I, II, III, IV, V are correct
  • Only V is correct
Vapour pressure of a saturated solution of a sparingly soluble salt $$A_2B_3$$ is 31.8 mm of Hg at $$40^{\circ}C$$. If vapour pressure of pure water is 31.8 mm of Hg at $$40^{\circ}C$$ the solubility product of $$A_2B_3$$ at $$40^{\circ}C$$ is:
  • $$5.67\times 10^{-6}$$
  • $$1.42\times 10^{-6}$$
  • $$6.30\times 10^{-5}$$
  • 1
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 torn If the molecular mass of $$A$$ is 200 amu, then the molecular mass of $$B$$ is:
  • 100 amu
  • 90 amu
  • 75 amu
  • 120 amu
$${ \Delta  }_{ f }{ G }^{ }$$ at 500 K for substance $$S$$ in liquid state and gaseous state are +100.7 kcal $${ }^{ -1 }$$ and +103 kcal $${ }^{ -1 }$$, respectively. Vapour pressure of liquid $$S$$ at 500 K is approximately equal to:
($$R=2\ cal $$ $${ K }^{ -1 }{ }^{ -1 }$$)
  • 0.1 atm
  • 10 atm
  • 100 atm
  • 1 atm
The vapour pressure of a pure liquid $$A$$ is $$70$$ torr at $$27^oC$$. 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 $$27^oC$$. The vapour pressure of pure liquid $$B$$ at $$27^o$$C is:
  • $$14$$
  • $$56$$
  • $$140$$
  • $$70$$
At what temperature, the sample of neon gas would be heated to double its pressure, if the initial volume of gas is reduced by $$15$$% at $${75}^{o}C$$?
  • $${319}^{o}C$$
  • $${592}^{o}C$$
  • $${128}^{o}C$$
  • $${60}^{o}C$$
At $$20^{o}C$$, the vapour pressure of $$0.1\ M$$ solution of urea is $$0.0311\ mm$$ less than that of water and the vapour pressure of $$0.1\ M$$ solution of $$KCl$$ is $$0.0574\ mm$$ less than that of water. The apparent degree of dissociation of $$KCl$$ at this dilution is :
  • $$92.1\%$$
  • $$84.6\%$$
  • $$68.4\%$$
  • $$54.1\%$$
100 g of liquid $$A$$ (molar mass 140 g $$mol^{-1}$$) was dissolved in 1000 g of liquid $$B$$ (molar mass 180 g $$mol^{-1}$$) The vapour pressure of pure liquid $$B$$ was found to be 500 torr. 

Calculate the vapour pressure of pure liquid $$A$$ and its vapour pressure in the solution if the total vapour pressure of the solution is 475 torr:
  • $$3.19, 500$$
  • $$283.18, 31.999$$
  • $$500, 300$$
  • $$190, 31.965$$
If $${ CuSO }_{ 4 }\cdot 5H_{ 2 }O\left( s \right) \rightleftharpoons { CuSO }_{ 4 }\cdot { 3H }_{ 2 }O\ (s)+{ 2H }_{ 2 }O\ (l){ K }_{ p }=1.086\times { 10 }^{ -4 }{ atm }^{ 2 }\ at\ { 25 }^{ o }C$$ The efflorescent nature of $${CuSO}_{4}\cdot \ {5H}_{2}O$$ can be noticed when vapour pressure of $$ {H}_{2}O$$ in atmosphere is:
  • $$>7.92\ mm$$
  • $$<7.92\ mm$$
  • $$\gtrless7.92\ mm$$
  • none of these
A solution of a non-volatile solute in water has a boiling point of 375.3K. Calculate the vapour pressure of water above this solution at 338K. Given, Po (water) = 0.2467 atm at 338K and Kb for water = 0.52.
  • $$0.18\ atm$$
  • $$0.23\ atm$$
  • $$0.34\ atm$$
  • $$0.925\ atm$$
Which of the following has least vapour presure ?
  • $$0.1\ M\ NaCl$$
  • $$0.1\ M\ MgCl_{2}$$
  • $$0.1\ M\ AlCl_{3}$$
  • $$0.1\ M\ K_4[Fe(CN)_{6}]$$
Which of the following change is observed occurs when a substance X is converted from liquid to vapour phase at the standard boiling point?
I.Potential energy of the system decreases
II. The distance between molecules increases
III. The average kinetic energy of the molecules in both phases are equal.
  • I only
  • II only
  • III only
  • II and III only
In the given equilibrium, $${ H }_{ 2 }O(l)\rightleftharpoons { H }_{ 2 }O(g)$$ at $$100^oC$$ the vapour pressure is $$1 \ atm$$. If the volume of the container is halved, after sometime the vapour pressure becomes:
(assuming constant temperature)
  • $$1.5 atm$$
  • $$2.5 atm$$
  • $$2 atm$$
  • $$1 atm$$
Which solution has the highest vapour pressure?
  • 0.02 M $$NaCl$$ at $$50^o C$$
  • 0.03 M sucrose at $$15^oC$$
  • 0.005 M $$CaCl_2$$ at $$50^oC$$
  • 0.005 M $$CaCl_2$$ at $$25^oC$$
3.6 gm of $$O_2$$ is adsorbed on 1.2 gr of metal powder. What volume of $$O_2$$ adsorbed per gram of the absorbant at 1 atm and 273K?
  • 2.1
  • 0.19
  • 1
  • None
The solubility of a specific non-volatile salt is 4g in 100 g of water at $${25}^{0}$$C. If 2.0g, 4.0g and 6.0g of the salt added of 100g of water at $${25}^{0}$$C, in system X, Y and Z. The vapour pressure would be in the order:
  • $$Z>Y>X$$
  • $$X>Y>Z$$
  • $$Z>X=Y$$
  • $$X>Y=Z$$
The pressure exerted by a mass of x mg resting on the area of 1.00 $${ cm }^{ 2 }$$ is 1.00 Pa, then x is
  • 10.6
  • 10.3
  • 103
  • 10.2
Reaction of $${NO}$$ takes place with hydrogen if equal molar mixture of snow and hydrogen is taken at initial total pressure of 350 mm of Mercury, total pressure reduces to half its value after 121 seconds while if initial total pressure would have been 275 mm it reduces to half of the 196 seconds calculate the order of reaction?
  • 0
  • 1
  • 2
  • 3
The brown gas Y in the mixture is?
  • Nitric oxide
  • Nitrous oxide
  • Dinitrogen tetroxide
  • Nitrogen dioxide
The empirical formula of a  monobasic acid is $${CH}_{2}O$$. The vapour density of its ethyl ester is $$44$$. What is the Molecular formula of the acid?
  • $${C}_{2}{H}_{4}{O}_{2}$$
  • $${CH}_{2}{O}_{2}$$
  • $${C}_{2}{H}_{2}{O}_{2}$$
  • $${C}_{3}{H}_{6}{O}_{3}$$
The colourless gas X in the mixture is:
  • Bromine
  • Pure nitrogen dioxide
  • Dinitrogen tetraoxide
  • Nitric oxide
Moles of $$Na_2SO_4$$ to be dissolved in 12 mole of water to lower its vapour pressure by 10 millimeter Mercury at a temperature at which vapour pressure of pure water is 50 millimeters?
  • 1.5 moles
  • 2 moles
  • 1 mole
  • 3 moles
According to kinetic theory of gases :
  • collisions are always elastic
  • between collisions, the molecules move in straight lines with constant velocities
  • only a small number of molecules have a very high velocity
  • at of the above
A spherical balloon of $$21\ cm$$ diameter is to be filled up with $$H_2$$ at $$NTP$$ from a cylinder containing the gas at $$20\ atm$$ at $$27^{\circ}C$$. The cylinder can hold $$2.82$$ litre of water. The number of balloons that can be filled up
  • 11
  • 10
  • 8
  • 1
In a gaseous mixture at $$20^o C$$ the partial pressure of the components are:
$${ H }_{ 2 }$$ : 150 Torr      $${ CH }_{ 4 }$$ : 300 Torr     $${ CO }_{ 2 }$$ : 200 Torr        $${ C }_{ 2 }{ H }_{ 4 }$$ : 100 Torr
The volume % of $${ H }_{ 2 }$$ in mixture:
  • 26.67
  • 73.33
  • 80.00
  • 20
A beaker is filled with a liquid of density $$\rho $$ upto a height h if the beaker is at rest, the mean pressure at the walls is :
  • 0
  • $$h \rho g $$
  • $$h \rho g/2 $$
  • $$2 h \rho g $$
An aqueous solution containing liquid $$A(M.\ wt.\ =128)\ 64\%$$ by weight has a vapour pressure of $$145\ mm\ Hg$$. If the vapour pressure of water is $$155\ mm\ Hg$$ then vapour of $$A$$ at the same temperature will be
  • $$205\ mm\ Hg$$
  • $$105\ mm\ Hg$$
  • $$185\ mm\ Hg$$
  • $$52.5\ mm\ Hg$$
The reduction potential of hydrogen electrode will be positive if 
  • $${P_{{H_2}}} = 2\;atm;\left[ {H^ + } \right] = 1\;M$$
  • $${P_{{H_2}}} = 2.5\;atm;\left[ {H^ + } \right] = 1.5\;M$$
  • $${P_{{H_2}}} = 2.5\;atm;\left[ {H^ + } \right] = 1\;M$$
  • $${P_{{H_2}}} = 1\;atm;\left[ {H^ + } \right] = 2\;M$$
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