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 400$${ cm }^{ 3 }$$ is connected to another bulb of volume 200$${ cm }^{ 3 }$$ by means of a tube of negligible volume. The bulbs contain dry air and are both at a common temperature and pressure of $${ 20 }^{ 0 }$$C and 1.00 atm. The larger bulb is immersed in steam at $${ 100 }^{ 0 }$$C; the smaller, in melting ice at $${ 0 }^{ 0 }$$. 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 $$300$$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 $$Y$$?
  • $$20$$
  • $$10$$
  • $$100$$
  • $$30$$
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 $$145\ mm\ Hg$$. If the vapour pressure of water is $$155\ mm\ Hg$$ then vapour of $$A$$ at the same temperature will be
  • $$205\ mm\ Hg$$
  • $$105\ mm\ Hg$$
  • $$185\ mm\ Hg$$
  • $$52.5\ mm\ Hg$$
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 $$27^o$$C 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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