529 + Interview Questions in GASEOUS-STATE IN GENERAL AWARENESS Page 10 InterviewSolution

451.	A ballon filled with ethyne is pricked with a sharp point and quickly dropped in a tank of `H_(2)` gas under indentical conditions. After a while the balloon willA. ahrinkB. enlargeC. completely collapaeD. remained unchanged in size
Answer» Correct Answer - b

Discussion

452.	A balloon containing 1 mole air at 1 atm initially is filled further with air till pressure increases to 4 atm. The intial diameter of the ballon is 1 m and the pressure at each stage is proportional to diameter of the balloon. How many moles of air added to change the pressure from 1 atm to 4 atm.A. 80B. 257C. 255D. 256
Answer» Correct Answer - c (c) `P prop d, p=kd and k=(1 "atm")/(1 "metre")` `PV=nRT, kd((1)/(6)pid^(3))=nRT,` `(d_(1)^(4))/(d_(2)^(4))=(n_(1))/(n_(2)),(1)/(4^(4))=n_(1)//n_(2),n_(2)=256` no. of moles added=256 - 1 =255

Discussion

453.	Pay load is defined as the difference between the mass of displaced air and the mass of the ballon Calculate the pay-load when a balloon of radius `10m` mass `100 kg` is filled with helium at 1.66 bar at `27^(@)C` (Density of air ` = 1.2 kg m^(-3)` and `R = 0.083` nar `dm^(-3) K^(-1) mo1^(-1)`) .
Answer» Weight of balloon `=100 kg = 100 xx 10^(3) g = 10^(5) g` Volume of balloon ` = (4)/(3) pir^(3) = (4)/(3) xx (22)/(7) xx (10 xx 100)^(3) cm^(3)` `=4190 xx 10^(6) cm^(3) = 4190 xx 10^(3) litre` Weight of the gas filled in ballon ` = (PVm)/(RT) = (1.66 xx 4190 xx 10^(3) xx 4)/(0.083 xx 300) = 1.117 xx 10^(6) g` Total weight of (gas+ballon) `11.17 xx 10^(5) + 10^(5) = 12. 17 xx 10^(5) g` Weight of air displaced (Volume x density) by balloon `= 1.2 xx 10^(-3) xx 4190 xx 10^(6)` `5.028 xx 10^(6)g` `:.` Pay load `=50.28 xx 10^(5) -12.17 xx 10^(5)` `=38.11 xx 10^(5) g =3811 kg` .

Discussion

454.	At `27^(@)C`, a ges is compressed to half of its volume . To what temperature it must now be heated so that gas occupies just its original volume ?A. `54^(@)C`B. `600^(@)C`C. `327^(@)C`D. `327K`
Answer» Correct Answer - 3 `V_(i)//T_(f)=V_(f)//T_(f)(` at constant pressure ) `V_(i)=V//2,T_(i)=300K` `V_(f)=V_(i)T_(f)=600K`

Discussion

455.	A gas bulb of `1 L` capacity contains `2.0xx10^(11)` molecules of nitrogen exerting a pressure of `7.57xx10^(3)Nm^(-2)`. Calculate the root mean square (rms) speed and the temperature of the gas molecules. If the ratio of the most probable speed to the root mean square is `0.82`, calculate the most probable speed for these molecules at this temperature.
Answer» Given `P =7.57 xx 10^(3) Nm^(-2), V = 1 litre = 10^(-3) m^(3)` `R = 8.314 J, n = (2 xx 10^(21))/(6.023 xx 10^(23)` mole Using `PV =nRT` `7.57 xx 10^(3) xx 10^(-3) = (2 xx 10^(21))/(6.023 xx 10^(23)) xx 8.314 xx T` `T =274.2 K` `:. u_(rms) = sqrt(((3RT)/(M))) =sqrt(((3 xx 8.314 xx 274.2)/(28 xx 10^(-3)))` (M in kg) `= 494.22 m sec^(-1)` Now `u_(MP)/(u_(rms))=0.82` `u_(MP) = 405.26 m sec^(-1)` .

Discussion

456.	`{:(,"Coloumn-I",,"Column-II"),("(a)","At low pressure",,(p)Z=1+(pb)/(RT)),("(b)","At high pressure",,(q)Z=1-a/(V_(m)RT)),("(c)","At low density of gas",,"(r)Gas is more compressible then ideal gas"),("(d)",for H_(2) and He at 0^(@) C,,"(s)Gas is less compressible than ideal gas"):}`
Answer» Correct Answer - (a-q,r);(b-p,s);(c-q,r);(d-p,s)

Discussion

457.	According to virial equation of state for 1 mole of a real gas `PV_(M)=RT[A+(B)/(V_(M))+(C)/(V^(2_(M)))+...]` which one is not correct ? .A. A is independent of temperatureB. `B` has the dimensions of molar volumeC. `A,B` and `C` are negligible at Boyle temperatureD. `A` is unity at Boyle temperature whereas `B` and `C` are negligible at Boyle temperature .
Answer» At Boyle temperature `A =1` and `B,C` are negligible, thus `PV =RT` .

Discussion

458.	For a real gas, following equation `(P+(a)/(TV_(m)^(2)))(V_(m)-beta)=RT`, where `alpha `and `beta` are positive constants. Select the correct option(s):A. `T_(C)=(8alpha)/(27Rbeta)`B. `V_(cm)=3beta`C. Second virial coefficient `=beta-(alpha)/(RT)`D. Third virial coefficient `=beta^(2)`
Answer» Correct Answer - bd

Discussion

459.	The radius of an Xe atom is `1.3 xx 10^(-8)` cm A `100 cm^(3)` container is filled with Xe at a pressure of 1.0 atm and a temperature of `273K` Calculate the fraction of the volume that is occupied by Xe atoms .
Answer» Correct Answer - `2.474 xx10^(-2)`

Discussion

460.	At `20^(@)C` two balloons of equal volume and porosity are filled to a pressure of 2 atm one with `14kgN_(2)` and other with `1kg` of `h_(2)` The `N_(2)` balloon leaks to a pressure of `1//2` atm in 1hr How long will it take for `H_(2)` balloon to reach a pressure of `1//2atm` ? .
Answer» Correct Answer - 16 minute

Discussion

461.	Which pair of gases has the same average rate of diffusion at `25^(@)C`?A. He and NeB. `N_(2)` and `O_(2)`C. `N_(2)O` and `CO_(2)`D. `NH_(3)` and `HCl`
Answer» Correct Answer - c

Discussion

462.	The ratio rate of diffusion of gases `A` and `B` is 1:4 If the ratio of their masses oresent in the initial mixture is `2:3` calculate the ratio of their mole fraction .
Answer» Correct Answer - 0.347

Discussion

463.	Find he number of diffusion steps required to separated the isotopic mixture initially containing some amound of `H_(2)` gas 1 mol of `D_(2)` gas in a container of 3 litre capacity maintained at 24.6 atm and `27^(@)C` to the final mass ratio `((W_(D_(2)))/(W_(H_(2))))` equal to `(1)/(4)`
Answer» Correct Answer - `0004`

Discussion

464.	The density of `O_(2)"(g)" ` is maximum at :A. STPB. 273 K and 2 atmC. 546 K and 1 atmD. 546 K and 2 atm
Answer» Correct Answer - b (b) `d=(PMw)/(dRT)`

Discussion

465.	Pure `O_(2)` diffuses through an aperture in 224 second, whereas mixture of `O_(2)` and another gas containing 80% `O_(2)` diffuses from the same in 234 second. The molecular mass of gas will be:A. 45.6B. 48.6C. 50D. 46.6
Answer» Correct Answer - d

Discussion

466.	Calculate the volue of `O_(2)` at 1 atm and 273 K required for the complete combustion of 2.64 L of acetylene `(C_(2)H_(2))` at 1 atm and 273 K. `2C_(2)H_(2)"(g)"+5O_(2)"(g)"rarr4CO_(2)"(g)"+2H_(2)O(l)`A. 3.6 LB. 1.056 LC. 6.6 LD. 10 L
Answer» Correct Answer - c (c) `n_(c_(2))H_(2)=(PV)/(RT)=(1xx2.64)/(0.0821xx273)=0.118"mole"` `n_(O_(2))=(5)/(2)xx0.118=0.294` `V=(nRT)/(P)=6.6L`

Discussion

467.	An open vessel containing air is heated form `300 K` to `400 K`. The fraction of air originally present which goes out of it is at `400 K`A. `3//4`B. `1//4`C. `2//3`D. `1//8`
Answer» One heating the gas in open vessel AT `300 K , P_(1) V_(1) = n_(1) R 300` At `400 K, P_(1) V_(1) =n_(2) R 400` `(n_(1))/(n_(2)) = (400)/(300)` `n_(2) = (3)/(4) n_(1)` Thus `(1)/(4) n_(1)` gas is given out .

Discussion

468.	Calculate the change in pressure when `1.04` mole of `NO` and `20.0gO_(2)` in a `20.0L` vessel originally at `27^(@)C` react to produce maximum quantity of `NO_(2(g))` according to reaction `2NO_((g)) +O_(2(g))rarr2NO_(2(g))` .
Answer» Correct Answer - 0.64 atm

Discussion

469.	A 3.0L sample of helium gas is stored in a rigid, sealed container at `25^(@)C` and 1.0 atm pressure. The temperature is increased to `125%(@)C`. What is the new pressure of the gas?A. 0.20atmB. 0.75atmC. 1.33atmD. 5.0atm
Answer» Correct Answer - c

Discussion

470.	A vessel contains equal masses of three gases A,B, C and recorded a pressure of 3.5 bar at `25^(@)C`. The molecular mass of C is twce that of B and pressure of B (in bar) in the vesselA. 3B. 2C. 4D. 1
Answer» Correct Answer - d

Discussion

471.	Equal weights of ethane and hydrogen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by hydrogen isA. `1:2`B. `1:1`C. `1:16`D. `15:16`
Answer» Correct Answer - d

Discussion

472.	Which property is the same for 1.0g samples of `H_(2)` and `CH_(4)` in separate 1.0L containers at `25^(@)C`?A. Pressure in I is the maximum.B. Number of moleculesC. Average molecular velocityD. Average molecular kinetic energy
Answer» Correct Answer - d

Discussion

473.	A mixture of 0.50 mol of `H_(2)` gas and 1.3 mol of Ar gas is in a sealed container with a volume of 4.82L. If the temperature of the mixture is `50.0^(@)C`, what is the partial pressure of `H_(2)` in the sample?A. 1.5atmB. 2.8atmC. 7.2atmD. 9.9atm
Answer» Correct Answer - b

Discussion

474.	Calculate the compressibility factor for `SO_(2)` if 1 mole of it occupies 0.35 litre at `300K` and 50 atm pressure Comment on the result .
Answer» Compressibility factor `(Z) =(PV)/(nRT)` `Z = (40 xx 0.4)/(1 xx 0.0821 xx 300) = 0.65` Since `Z` value is lesser than 1 and thus , `nRT gtPV` In order to have `Z =1` volume of `CO_(2)` must have been more at same `P` and `T` or `Co_(2)` is more compressible than ideal gas .

Discussion

475.	Two flask A and B of equal volumes maintained at temperature `300K` and `700K` contain equal mass of `He(g)` and `N_(2)(g)` respectively. What is the ratio of total translational kinetic energy of gas in flask A to that of flask B ?A. `1:3`B. `3:1`C. `3:49`D. None of these
Answer» Correct Answer - 2 Moles ratio `= (n_(He))/(n_(H_(2)))=(w//4)/(w//28)=(7)/(1)` Ratio of translational `K.E.=(n_(He).T_(He))/(n_(N_(2)).T_(N_(2)))=(7)/(1)xx(300)/(700)=3:1`

Discussion

476.	Calculate the compressibiity factor for `CO_(2)`, if one mole of it occupies 0.4 litre at 300K and 40 atm. Comment on the result.A. 0.40, `CO_(2)` is more compressible than ideal gasB. 0.65,`CO_(2)` is more compressible than ideal gasC. 0.55,`CO_(2)` is more compressible than ideal gasD. 0.62,`CO_(2)` is more compressible than ideal gas
Answer» Correct Answer - b

Discussion

477.	A 20 litre container at 400 K contains `CO_(2)(g)` at pressure `0.4 atm` and an excess of SrO (neglect the volume of slid `SrO)`. The volume of the container is now decreased by moving the movable piston fitted in the container . The maximum volume of the container, when pressure of `CO_(2)` attains its maximum value, will be [Given that `: SrCO_(3)(s) hArr SrO(s) +CO_(2)(g), Kp=1.6 atm]`A. 10 litreB. 4 litresC. 2 litreD. 5 litre
Answer» Correct Answer - D `SrCO_(3)hArrSrO(s)+CO_(2)(g)(s) ` `K_(p)= P_(CO_(2))` maximum pressure of `CO_(2)= 1.6 atm` `P_(1)V_(1)=P_(2)V_(2)` `0.4 xx 20 = 1.6 V_(2) implies V_(2)= 5L`.

Discussion

478.	Equal weights of methane and oxygen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by oxygen isA. `(1)/(3)`B. `(1)/(2)`C. `(2)/(3)`D. `(1)/(3) xx (273)/(298)`
Answer» Correct Answer - A Pressure exerted by oxygen will be proportinoal to mole fraction of `O_(2)`. Mole fraction of `O_(2)=((W)/(32))/((W)/(16)+(W)/(32))=(1)/(3)`

Discussion

479.	Equal masses of methane and oxygen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by oxygen is:A. `(2)/(3)`B. `(1)/(3) xx (273)/(298)`C. `(1)/(3)`D. `(1)/(2)`
Answer» Correct Answer - C Let the mass of methane and oxygen is w mole fraction of oxygen `=((w)/(32))/((w)/(32)+(w)/(16))` `=((1)/(32))/((1)/(32)+(1)/(16))=((1)/(32))/((3)/(32))=(1)/(3)` Let the toal pressure be P The pressure exerted by oxygen ( partial pressure ) `= X_(O_(2))xxP_("total") implies Pxx(1)/(3)` , Hence, (c ) is correct .

Discussion

480.	What is the total pressure exerted by the mixture of `7.0g ` of `N_(2),2g` of hydrogen and `8.0g` of sulphur dioxide gases in a vessel of `6L` capacity that has been kept at `27^(@)C`.A. `2.5` barB. 4.5 barC. 10 `atm`D. 5.7 bar
Answer» Correct Answer - 4 No. of moles of `N_(2)=(7)/(28)=(1)/(4)` moles No. of moles of `H_(2)=1` moles No. of moles of `SO_(2)=(1)/(8)` moles Total moles `=(1)/(4)+1+(1)/(8)=(11)/(8)` `P=(nRT)/(V)=(11)/(8)xx(0.0821xx300)/(6)=5.64~~5.7atm`

Discussion

481.	A polythene bag of 3 litre capacity is filled by helium gas (Occupying 1L at 0.3 atm and 300K) at 300K . Subsequently enough Ne gas is filled to make total pressure 0.4 atm at 300K. Calculate ratio of moles of Ne to He in container.A. 4B. 2C. 1D. 3
Answer» Correct Answer - d

Discussion

482.	The pressure exerted by `6.0 g` of methane gas in a `0.03 m^(3)` vessel at `129^(@)C` is: (Atomic masses of `C= 12.01, H= 1.01 and R= 8.314 JK^(-1)mol^(-1)`)A. 215216 PaB. 13409 PaC. 41648 PaD. 31684 PA
Answer» Correct Answer - C `PV =nRT` `P =(6)/(16.05) xx (8.314 xx 402)/(0.03)~~ 41648 Pa`

Discussion

483.	4 litre `C_(2)H_(4)` (g) burns in oxygen at `27^(@)C` and 1 atm to produce `CO_(2)` (g) and `H_(2)O` (g) Calculate the volume of `CO_(2)` formed at (a) `27^(@)C` and 1 atm (b) `127^(@) C` and 1atm ( c) `27^(@)C` and 4 atm .
Answer» Correct Answer - 2 `C_(2)H_(4_(g)) + 30_(2_(g))rarr2CO_(2(g)) + 2H_(2)O_(g)` `:. 1` mole or volume of `C_(2)H_(4)` gives `= 2` volume of `CO_(2)` `:. 4` volume of `C_(2)H_(4)` gives ` =2 xx 4= 8` litre of `CO_(2)` Now at `27^(@)C` and `4atm` `(P_(1)V_(1))/(T_(1)) = (P_(2)V_(2))/(T_(2)) = (1xx8)/(300) = (4xxV_(2))/(300)` `V_(2) = 2` litre .

Discussion

484.	A gaseous mixture of Ne and `O_(2)` is taken in a copper vessel of 200mL capacity at 6 bar and `27^(@)C`. The vapur density of the gaseous mixture is 11.5. Now, the vessel is heated to `127^(@)C`, at which half of the `O_(2)(g)` combined with the vessel forming a solid oxide of negligible volume. Neglecting thermal expansion in the vessel, the final partial pressure of `O_(2)(g)` is : (Ne=20)A. 1barB. 2 barC. 1.75barD. 7bar
Answer» Correct Answer - a

Discussion

485.	What pressure (in atm) will be exerted by a 1.00g sample of methane, `CH_(4)` in a 4.25L flask at `115^(@)C`?A. 0.139B. 0.33C. 0.467D. 7.5
Answer» Correct Answer - c

Discussion

486.	Oxygen, which is 16 times as dense as hydrogen, diffuses:A. `(1)/(16)` times as fastB. `(1)/(4)` times as fastC. 4 times as fastD. 16 times as fast
Answer» Correct Answer - b

Discussion

487.	A 0.50 L container is ocupied by nitrogen at a pressure of 800 torr and a temperature of `0^(@)C`. The container can only withstand a pressure of 3.0 atm. What is the highest temperature `("^(@)C)` to which the container may be heated?A. 505B. 450C. 625D. 560
Answer» Correct Answer - a (a) `(P_(1))/(T_(1))=(P_(2))/(T_(2))` `T_(2)=3xx(76)/(80)xx273`

Discussion

488.	A sample of air contains only `N_(2)O_(2)` and `H_(2)O`. It is saturated with water vapours and total pressure is 640 torr. The vapour pressure of water is 40 torr and the molar ratio of `N_(2):O_(2)` is 3:1. The partial pressure of `N_(2)` in the sample is :A. 540torrB. 900torrC. 1080torrD. 450torr
Answer» Correct Answer - d

Discussion

489.	Calculate the volume occupied by `7g CO` at `27^(@) C` and `750 mm` Hg .
Answer» Given `w_(CO) = 7g, P = (750 //760) atm` `m_(CO) = 28, T =300K` `PV = (w//m) RT` `:. (750)/(760) xx V = (7)/(28) xx 0.0821 xx 300` or `V =6.23 litre` .

Discussion

490.	Moist air is less dense than dry air at the same temperature and barometric pressure. Which is the best explanation for this observation?A. `H_(2)O` is a polar molecule but `N_(2)` and `O_(2)` are not.B. `H_(2)O` has a higher boiling point than `N_(2)` or `O_(2)`.C. `H_(2)O` has a lower molar mass than `N_(2)` or `O_(2)`.D. `H_(2)O` has a higher heat capacity than `N_(2)` or `O_(2)`.
Answer» Correct Answer - c

Discussion

491.	A mixture of 0.100mol of `N_(2)` and 0.20 mol of `O_(2)` is collected over `H_(2)O` at an atmospheric pressure of 750mm Hg and a temperature of `22^(@)C`. What is the partial pressure (in mmHg) of `O_(2)` in this mixture? `{:("Compound","Vapour pressure at" 22^(@)C),(H_(2)O,22mmHg):}`A. 478B. 485C. 500D. 515
Answer» Correct Answer - b

Discussion

492.	At `30^(@)C` dry air `[75 % N_(2)+25 % O_(2)]` is placed over `H_(2)O(l)` at 800 torr (combined pressure of all 3 gases). If pressure is gradually increased isothermally to 1560 torr, then calculate partial pressure of `O_(2)` at this pressure in torr. `[VP_(H_(2)O)=50 "torr at"30^(@)C]`
Answer» Correct Answer - 380

Discussion

493.	A sample f `O_(2)` gas is collected over water at `23^(@)C` at a barometric pressure of 751 mm Hg ( vapour pressure of water at `23^(@)C` is 21 mm Hg). The partial pressure of `O_(2)` gas in the sample collected isA. 21 mm HgB. 751 mm HgC. `0.96 atm`D. 1.02 atm
Answer» Correct Answer - C Pressure of `O_(2) ` (dry) `=751 - 21 = 730 mm` Hg `= (730)/(760)=0.96 atm`

Discussion

494.	If 250 mL of `N_(2)` over water at `30^(@)C` and a total pressure of 740 torr is mixed with 300 mL of Ne over water at `25^(@)C` and a total pressure of 780 torr, what will be the total pressure if the mixture is in a 500 mL vessel over water at `35^(@)C`. (Given : Vapour pressure (Aqueous tension )of `H_(2)O` at `25^(@)C` and `35^(@)C` are 23.8, 31.8 and 42.2 torr respectively. Assume volume of `H_(2)O(l)` is negligible in final vessel)A. 760 torrB. 828.4 torrC. 807.6 torrD. 870.6 torr
Answer» Correct Answer - d (d) `n_(N_(2))=(((708.2)/(760)xx0.25))/(0.0821xx303)=9.36xx10^(-3)` `n_(o_(2))=(((756.2)/(760))xx0.3)/((0.0821)xx298)` `=0.0122` `n_("total")"moles"=0.02156` Pressure in final vessel = P `((n_("total"))RT)/(V)=(0.02156xx00821xx308)/(0.5)` P=1.09 atm or 828.4 torr `P_("total")=P_((O_(2)+N_(2)))+V.pr. "of "H_(2)O` `=828.4+42.2=870.6"torr" `

Discussion

495.	Pressure of `1g` of an ideal gas `A` at `27^(@)C` is found to be 2 bar when `2g` of another ideal gas `B` is introduced in the same flask at same temperature the pressure becomes 3 bar. Find a relationship thieir molecular masses .
Answer» Given of gas `A: w = 1g, T = 300 K,P =2`bar for gas `B: w = 2g.T = 300 K: P =3 -2 = 1`bar `(gas B +gas A)` mixture shows a pressure =3 bar For `A : p_(A) V =(w_(A))/(m_(A))RT` `P_(B) V =(w_(B))/(m_(B))RT` `(P_(A))/(P_(B)) = (w_(A))/(w_(B)) xx (m_(B))/(m_(A))` `(2)/(1) = (1)/(2) xx (m_(B))/(m_(A))` `(m_(A))/(m_(B)) = (1)/(4) :. m_(B) = 4m_(A)` .

Discussion

496.	`300 ml` of a gas at `27^(@)C` is cooled to `-3^(@)C` at constant pressure, the final volume isA. `540ml`B. `135ml`C. `270 ml`D. `350 ml`
Answer» Correct Answer - C `(V_(1))/(T_(1))=(V_(2))/(T_(2))` `(300)/(27+273)=(V)/(-3+273)` `=V=270ml.`

Discussion

497.	An ideal gas is trapped between a mercury column and the closed lower end of a narrow vertical tube of uniform bore. The upper end of the tube is open to atmosphere (atmospheric pressure = 76 cm of Hg). The length of mercury and the trapped gas columns are 20 cm and 43 cm respectively. What will be the length of the gas column when the tube is titled slowly at constant temperature in a vertical plane through an angle of `60^(@)` ?
Answer» Correct Answer - `0048`

Discussion

498.	The deviations from ideal gas behaviour `PV =RT` were successfully explained by van der Waals he pointed out that it is not advisable to neglect the volume of molecules and attractions between themselves at all the conditions He proposed volume correction and pressure correction as `(V -b) and ( P+(a)/(V^(2)))` for 1 mole of gas in ideal gas equation . The compressibility factor `Z` is greater than unity the at `STP,V_(m)` in litre is .A. `V_(m) gt22.4`B. `V_(m) lt22.4`C. `V_(m) =22.4`D. `V_(m) = 44.8`
Answer» For ideal gas at `NTP,PV =RT :. RT =24.4` litre For real gas at `NTP, (PV)/(RT) gt1` or ` 1 xx V gt RT` or `V gt 22.4` .

Discussion

499.	`{:(,"List-I(Van der Waals equation)",,"List-II(given by)"),("(a)","high pressure and low temperature",,"(p)PV=RT+Pb"),("(b)","low pressure",,(q)PV=RT-a//V),("(c)","Force of attraction is negligible",,"(r)PV=RT+aV"),("(d)","volume of molecule is negligible",,"(s)[P+a/V^(2)](V-b)=RT):}`
Answer» Correct Answer - (a-p);(b-q);(c-p);(d-q)

Discussion

500.	Considering the van der Waals equation of state `(P+a//V^(2))(V-b) =RT` for ammonia `(NH_(3))` and nitrogne `(N_(2))` the value of a for `NH_(3)` is larger than that of `N_(2)` Ammonia has a lower molecular weight than nitrogen .
Answer» Both are correct but does not give correct explanation .

Discussion

Explore topic-wise InterviewSolutions in .

A ballon filled with ethyne is pricked with a sharp point and quickly dropped in a tank of `H_(2)` gas under indentical conditions. After a while the balloon willA. ahrinkB. enlargeC. completely collapaeD. remained unchanged in size

Pay load is defined as the difference between the mass of displaced air and the mass of the ballon Calculate the pay-load when a balloon of radius `10m` mass `100 kg` is filled with helium at 1.66 bar at `27^(@)C` (Density of air ` = 1.2 kg m^(-3)` and `R = 0.083` nar `dm^(-3) K^(-1) mo1^(-1)`) .

At `27^(@)C`, a ges is compressed to half of its volume . To what temperature it must now be heated so that gas occupies just its original volume ?A. `54^(@)C`B. `600^(@)C`C. `327^(@)C`D. `327K`

`{:(,"Coloumn-I",,"Column-II"),("(a)","At low pressure",,(p)Z=1+(pb)/(RT)),("(b)","At high pressure",,(q)Z=1-a/(V_(m)RT)),("(c)","At low density of gas",,"(r)Gas is more compressible then ideal gas"),("(d)",for H_(2) and He at 0^(@) C,,"(s)Gas is less compressible than ideal gas"):}`

For a real gas, following equation `(P+(a)/(TV_(m)^(2)))(V_(m)-beta)=RT`, where `alpha `and `beta` are positive constants. Select the correct option(s):A. `T_(C)=(8alpha)/(27Rbeta)`B. `V_(cm)=3beta`C. Second virial coefficient `=beta-(alpha)/(RT)`D. Third virial coefficient `=beta^(2)`

The radius of an Xe atom is `1.3 xx 10^(-8)` cm A `100 cm^(3)` container is filled with Xe at a pressure of 1.0 atm and a temperature of `273K` Calculate the fraction of the volume that is occupied by Xe atoms .

At `20^(@)C` two balloons of equal volume and porosity are filled to a pressure of 2 atm one with `14kgN_(2)` and other with `1kg` of `h_(2)` The `N_(2)` balloon leaks to a pressure of `1//2` atm in 1hr How long will it take for `H_(2)` balloon to reach a pressure of `1//2atm` ? .

Which pair of gases has the same average rate of diffusion at `25^(@)C`?A. He and NeB. `N_(2)` and `O_(2)`C. `N_(2)O` and `CO_(2)`D. `NH_(3)` and `HCl`

The ratio rate of diffusion of gases `A` and `B` is 1:4 If the ratio of their masses oresent in the initial mixture is `2:3` calculate the ratio of their mole fraction .

Find he number of diffusion steps required to separated the isotopic mixture initially containing some amound of `H_(2)` gas 1 mol of `D_(2)` gas in a container of 3 litre capacity maintained at 24.6 atm and `27^(@)C` to the final mass ratio `((W_(D_(2)))/(W_(H_(2))))` equal to `(1)/(4)`

The density of `O_(2)"(g)" ` is maximum at :A. STPB. 273 K and 2 atmC. 546 K and 1 atmD. 546 K and 2 atm

Pure `O_(2)` diffuses through an aperture in 224 second, whereas mixture of `O_(2)` and another gas containing 80% `O_(2)` diffuses from the same in 234 second. The molecular mass of gas will be:A. 45.6B. 48.6C. 50D. 46.6

Calculate the volue of `O_(2)` at 1 atm and 273 K required for the complete combustion of 2.64 L of acetylene `(C_(2)H_(2))` at 1 atm and 273 K. `2C_(2)H_(2)"(g)"+5O_(2)"(g)"rarr4CO_(2)"(g)"+2H_(2)O(l)`A. 3.6 LB. 1.056 LC. 6.6 LD. 10 L

An open vessel containing air is heated form `300 K` to `400 K`. The fraction of air originally present which goes out of it is at `400 K`A. `3//4`B. `1//4`C. `2//3`D. `1//8`

Calculate the change in pressure when `1.04` mole of `NO` and `20.0gO_(2)` in a `20.0L` vessel originally at `27^(@)C` react to produce maximum quantity of `NO_(2(g))` according to reaction `2NO_((g)) +O_(2(g))rarr2NO_(2(g))` .

A 3.0L sample of helium gas is stored in a rigid, sealed container at `25^(@)C` and 1.0 atm pressure. The temperature is increased to `125%(@)C`. What is the new pressure of the gas?A. 0.20atmB. 0.75atmC. 1.33atmD. 5.0atm

A vessel contains equal masses of three gases A,B, C and recorded a pressure of 3.5 bar at `25^(@)C`. The molecular mass of C is twce that of B and pressure of B (in bar) in the vesselA. 3B. 2C. 4D. 1

Equal weights of ethane and hydrogen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by hydrogen isA. `1:2`B. `1:1`C. `1:16`D. `15:16`

Which property is the same for 1.0g samples of `H_(2)` and `CH_(4)` in separate 1.0L containers at `25^(@)C`?A. Pressure in I is the maximum.B. Number of moleculesC. Average molecular velocityD. Average molecular kinetic energy

A mixture of 0.50 mol of `H_(2)` gas and 1.3 mol of Ar gas is in a sealed container with a volume of 4.82L. If the temperature of the mixture is `50.0^(@)C`, what is the partial pressure of `H_(2)` in the sample?A. 1.5atmB. 2.8atmC. 7.2atmD. 9.9atm

Calculate the compressibility factor for `SO_(2)` if 1 mole of it occupies 0.35 litre at `300K` and 50 atm pressure Comment on the result .

Two flask A and B of equal volumes maintained at temperature `300K` and `700K` contain equal mass of `He(g)` and `N_(2)(g)` respectively. What is the ratio of total translational kinetic energy of gas in flask A to that of flask B ?A. `1:3`B. `3:1`C. `3:49`D. None of these

Equal weights of methane and oxygen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by oxygen isA. `(1)/(3)`B. `(1)/(2)`C. `(2)/(3)`D. `(1)/(3) xx (273)/(298)`

Equal masses of methane and oxygen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by oxygen is:A. `(2)/(3)`B. `(1)/(3) xx (273)/(298)`C. `(1)/(3)`D. `(1)/(2)`

What is the total pressure exerted by the mixture of `7.0g ` of `N_(2),2g` of hydrogen and `8.0g` of sulphur dioxide gases in a vessel of `6L` capacity that has been kept at `27^(@)C`.A. `2.5` barB. 4.5 barC. 10 `atm`D. 5.7 bar

A polythene bag of 3 litre capacity is filled by helium gas (Occupying 1L at 0.3 atm and 300K) at 300K . Subsequently enough Ne gas is filled to make total pressure 0.4 atm at 300K. Calculate ratio of moles of Ne to He in container.A. 4B. 2C. 1D. 3

The pressure exerted by `6.0 g` of methane gas in a `0.03 m^(3)` vessel at `129^(@)C` is: (Atomic masses of `C= 12.01, H= 1.01 and R= 8.314 JK^(-1)mol^(-1)`)A. 215216 PaB. 13409 PaC. 41648 PaD. 31684 PA

4 litre `C_(2)H_(4)` (g) burns in oxygen at `27^(@)C` and 1 atm to produce `CO_(2)` (g) and `H_(2)O` (g) Calculate the volume of `CO_(2)` formed at (a) `27^(@)C` and 1 atm (b) `127^(@) C` and 1atm ( c) `27^(@)C` and 4 atm .

What pressure (in atm) will be exerted by a 1.00g sample of methane, `CH_(4)` in a 4.25L flask at `115^(@)C`?A. 0.139B. 0.33C. 0.467D. 7.5

Oxygen, which is 16 times as dense as hydrogen, diffuses:A. `(1)/(16)` times as fastB. `(1)/(4)` times as fastC. 4 times as fastD. 16 times as fast

A 0.50 L container is ocupied by nitrogen at a pressure of 800 torr and a temperature of `0^(@)C`. The container can only withstand a pressure of 3.0 atm. What is the highest temperature `("^(@)C)` to which the container may be heated?A. 505B. 450C. 625D. 560

Calculate the volume occupied by `7g CO` at `27^(@) C` and `750 mm` Hg .

At `30^(@)C` dry air `[75 % N_(2)+25 % O_(2)]` is placed over `H_(2)O(l)` at 800 torr (combined pressure of all 3 gases). If pressure is gradually increased isothermally to 1560 torr, then calculate partial pressure of `O_(2)` at this pressure in torr. `[VP_(H_(2)O)=50 "torr at"30^(@)C]`

A sample f `O_(2)` gas is collected over water at `23^(@)C` at a barometric pressure of 751 mm Hg ( vapour pressure of water at `23^(@)C` is 21 mm Hg). The partial pressure of `O_(2)` gas in the sample collected isA. 21 mm HgB. 751 mm HgC. `0.96 atm`D. 1.02 atm

Pressure of `1g` of an ideal gas `A` at `27^(@)C` is found to be 2 bar when `2g` of another ideal gas `B` is introduced in the same flask at same temperature the pressure becomes 3 bar. Find a relationship thieir molecular masses .

`300 ml` of a gas at `27^(@)C` is cooled to `-3^(@)C` at constant pressure, the final volume isA. `540ml`B. `135ml`C. `270 ml`D. `350 ml`

`{:(,"List-I(Van der Waals equation)",,"List-II(given by)"),("(a)","high pressure and low temperature",,"(p)PV=RT+Pb"),("(b)","low pressure",,(q)PV=RT-a//V),("(c)","Force of attraction is negligible",,"(r)PV=RT+aV"),("(d)","volume of molecule is negligible",,"(s)[P+a/V^(2)](V-b)=RT):}`

Considering the van der Waals equation of state `(P+a//V^(2))(V-b) =RT` for ammonia `(NH_(3))` and nitrogne `(N_(2))` the value of a for `NH_(3)` is larger than that of `N_(2)` Ammonia has a lower molecular weight than nitrogen .