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CBSE Questions for Class 11 Engineering Chemistry States Of Matter Quiz 12 - MCQExams.com

When a non volatile solute is added to a pure solvent, the :
  • vapour pressure of the solution becomes lower then that of the pure solvent
  • rate of evaporation of the pure solvent is reduced
  • solute does not effect the rate of condensation
  • rate of the evaporation of the solution is equal to the rate of condensation of the solution at a lower vapour pressure than that in the case of the pure solvent
When intermolecular attractive forces are neglected, isobar formed between V and T at constant p is of the type given in the figure.
Pressure at which isobar made is:
1035444_b9ef186e61fa440b89d6055a92aa566d.png
  • 2 atm
  • 0.5 atm
  • 1 atm
  • 4 atm
A glass bulb of volume 400cm3 is connected to another bulb of volume 200cm3 by means of a tube of negligible volume. The bulbs contain dry air and are both at a common temperature and pressure of 200C and 1.00 atm. The larger bulb is immersed in steam at 1000C; the smaller, in melting ice at 00. Find the final common pressure.
  • 1.563 atm
  • 2.05 atm
  • 2.36 atm
  • 1.134 atm
Vapour pressure of a pure liquid X is 2 atm at 300K. It is lowered to 1 atm on dissolving 1g of Y in 20g of liquid X. If molar mass of X is 200, what is the molar mass of Y?
  • 20
  • 10
  • 100
  • 30
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
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
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
An aqueous solution containing liquid A(M.\ wt.\ =128)\ 64\% by weight has a vapour pressure of 145\ mm\ HgIf 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
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}
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
{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
The K.E of N molecule of O_{2} is xjoules at__ {123}^{o}C. Another sample of O_{2} at {327}^{o}C has a K.E of 2x joules. The latter sample contains:
  • N molecules of O_{2}
  • 2N molecules of O_{2}
  • N/2 molecules of O_{2}
  • N/4 molecules of O_{2}
A volume V of a gas at a temperature T_{1} and a pressure p is enclosed in a sphere. It is connected to another sphere of volume V/2 by a tube and stopcock is opened the temperature of the gas in the second sphere becomes T_{2}. The first sphere is maintained at a temperature Y_{1}. What is the final pressure p_{1} within the apparatus?
  • \dfrac {2pT_{2}}{2T_{2}+T_{1}}
  • \dfrac {2pT_{2}}{T_{2}+2T_{1}}
  • \dfrac {pT_{2}}{2T_{2}+T_{1}}
  • \dfrac {2pT_{2}}{T_{1}+T_{2}}
The average velocity of an ideal gas molecule at {27}^{o}C is 0.3m/sec. The average velocity at {927}^{o}C will be:
  • 0.6m/sec
  • 0.3m/sec
  • 0.9m/sec
  • 3.0m/sec
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}
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
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
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
An inflated balloon has a volume of 6.0L at sea level (P=1atm) and is allowed to ascend in altitude until the pressure is 0.4atm. During the rise, the temperature of the gas falls from {27}^{o}C to -{23}^{o}C. The volume of balloon at its final altitude is
  • 12.5L
  • 15L
  • 10L
  • 3L
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 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
A container is divided into two compartment. One compartment contains 2 mole of N_{2} gas at 1 atm and 300\ K & other compartment contains H_{2} gas at the same temperature and pressure. Volume of H_{2} compartment is four times the volume of N_{2} compartment. [assume no reaction under these condition]
If the container containing N_{2} and H_{2} are further heated to 1000\ K forming NH_{3} with 100\% yield. Calculate the final total pressure.
  • 2.22\ atm
  • 3\ atm
  • 2\ atm
  • 3.33\ atm
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^{o}C. The number of molecules of the gas remaining in the tube is?
  • 3\times 10^{17}
  • 1.5\times 10^{14}
  • 4.5\times 10^{18}
  • 6\times10^{18}
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

An LPG cylinder can withstand pressure difference of 15 atm across its boundaries. If at room temp ({ 27 }^{ o }) it is filled with 2 atm pressure. Determine the temperature at which it will explode?

  • { 216 }^{ o }C
  • { 2127 }^{ o }C
  • { 2400 }^{ o }C
  • { 27 }^{ o }C

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
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
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
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
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
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^oC is:
  • 14
  • 56
  • 140
  • 70
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
Ammonium carbamate dissociates as:
N{ H }_{ 2 }COON{ H }_{ 4 }(s)\quad \rightleftharpoons \quad 2N{ H }_{ 3 }(g)\quad +\quad C{ O }_{ 2 }(g)
In a closed vessel containing ammonium carbamate in equilibrium, ammonia is added such that partial pressure of N{ H }_{ 3 } now equals to the original total pressure. Calculate the ratio of partial pressure of C{ O }_{ 2 } now to the original partial pressure of C{ O }_{ 2 }
  • 4
  • 9
  • \dfrac { 4 }{ 9 }
  • \dfrac { 2 }{ 9 }
A 3L container at 3 atm pressure consist a mixture of N_2 gas and H_2O vapours. Solid sphere of volume 0.5L is also present in same container. What will be the pressure of gas, if volume of container is reduced to 2L, at same temperature (AQ. tension = 0.2 atm)?
  • 5.4 atm
  • 4.2 atm
  • 4.87 atm
  • 5 atm
At same temperature N_2O_4 is dissolved to 40% and 50% at total presure p_1 and p_2 atm respevtively in NO_2.Then the ratio of P_1 &P_2 is?
  • \frac { 4 }{ 5 }
  • \frac { 7 }{ 4 }
  • \frac { 4 }{ 7 }
  • None of these
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\%
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}]
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
Plots of \cfrac { PV }{ RT } vsP for 1 mole of { H }_{ 2 }, { NH }_{ 3 } and { CH }_{ 4 } gases are given. Match the curve with corresponding gases
  Curve                                          Gas
(i) Curve 'a'                                    p- { H }_{ 2 } 
(ii) Curve 'b'                                   q- { NH }_{ 3 } 
(iii) Curve 'c'                                   r- { CH }_{ 4 } 
1134610_48a712196bf843c2b2e4256129786adc.JPG
  • (i)-p, (ii)-q, (iii)-r
  • (i)-q, (ii)-r, (iii)-p
  • (i)-p, (ii)-r, (iii)-q
  • (i)-r, (ii)-q, (iii)-p
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
0:0:1


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