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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 251. |
Assertion: Absolute zero temperature is a theoretically possible temperature at which the volume of the gas becomes zero. Reason: The total kinetic energy of molecules is zero at this temperature.A. Statement-I is True, Statement-II is True : Statement-II is a correct explanation for Statement-IB. Statement-I is True, Statement-II is True : Statement-II is `NOT` a correct explanation for Statement-IC. Statement-I is True, Statement-II is False.D. Statement-I is False, Statement-II is True. |
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Answer» Correct Answer - b |
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| 252. |
The ratio among most probable velocity, mean velocity and root mean velocity is given byA. `1:2:3`B. `1:sqrt(2):sqrt(3)`C. `sqrt(2):sqrt(3):sqrt(8//pi)`D. `sqrt(2):sqrt(8//pi):sqrt(3)` |
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Answer» Correct Answer - d (d) `a:v:u=sqrt(2):sqrt((8)/(pi)):sqrt(3)` |
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| 253. |
The root mean square velocity of hydrogen molecules at 300 K is `1930 ms^(-1)`. The rms velocity of oxygen molecules at 1200 K will beA. `7.6 xx 10^(3) m// `secB. `3.8 xx 10^(3) m// `secC. `0.95 xx 10^(3) m // `secD. `0.475 xx 10^(30 m // `sec |
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Answer» Correct Answer - C `C_(rms)=sqrt((3RT)/(M))` `C_(rms)(H_(2))=sqrt((3R xx 300)/(2))=1.9 xx 10^(3) m//sec` `C_(rms)(O_(2))= sqrt((3Rxx1200)/(32))= (2)/(4)(sqrt((3R xx 300)/(2)))` `=(1)/(2) (1.9 xx 10^(3))m//sec = 0.95 xx 10^(3) m //sec` |
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| 254. |
For one mole of ideal gas if `P=(P_(0))/(1+((V)/(V_(0))))` where `P_(0)` and `V_(0)` are constant, then temperature of gas when `V=V_(0)` is:A. `(P_(0)V_(0))/(R)`B. `(P_(0)V_(0))/(4R)`C. `(P_(0)V_(0))/(2R)`D. `(P_(0)V_(0))/(3R)` |
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Answer» Correct Answer - c |
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| 255. |
The kinetic theory of gases assumes all of the following except:A. Gases are composed of particles in random ceaseless motion.B. The sizes of gas particles are negligible compared to the size of the container.C. Gas particles do not attract or rapel each other.D. When gas particles collide, kinetic energy is lost. |
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Answer» Correct Answer - d |
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| 256. |
For one mole of an ideal gas, increasing the temperature from `10^(@)C` to `20^(@)C`A. Increases the average kinetic energy by two timesB. Increases the rms velocity by `sqrt(2)` timesC. Increase the rms velocity by two timesD. Increase both the average kinetic energy and rms velocity, but not significantly. |
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Answer» Correct Answer - D Initial temperature `= 283 K` Final temperature `= 293 K` `KE_(1)= (3RT_(1))/(2),KE_(2)=(3RT_(2))/(2)` `(KE_(1))/(KE_(2))=(T_(1))/(T_(2))= (283)/(293)== 0.96` `KE_(2)=1.04 KE_(1)` `v_(rms)=sqrt((3RT)/(M))implies (v_(1))/(v_(2))=sqrt((T_(1))/(T_(2)))impliessqrt((283)/(203))` `v_(2)=v_(1)sqrt((293)/(283))=1.02v_(1)` Both average K.E. and rms velocity increase but not significantly. |
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| 257. |
The compressibility of a gas is less than unity at `STP` .A. `V_(m) gt 22.4` litresB. `V_(m) lt 22.4` litresC. `V_(m) = 22.4` litresD. `V_(m) = 44.8` litres |
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Answer» Correct Answer - B `(PV)_("observed") //(PV)_("ideal") lt 1 implies V_(obs) lt V_("ideal") , V_(obs) lt 22.4 `litre. |
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| 258. |
The root mean square velocity of an ideal gas to constant pressure varies with density (`d`) asA. `d^(2)`B. `d`C. `sqrt(d)`D. `1//sqrt(d)` |
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Answer» Correct Answer - D `u_(RMS) = sqrt((3RT)/(M))` Using ideal gas equation. `PV = nRT = (w)/(M) RT, (RT)/(M) = (PV)/(w) =(P)/(d)` where d is the density of the gas `:. u _(RMS) = sqrt((3P)/(d)) ` at constant pressure , `u_(RMS)prop (1)/(sqrt(d))` |
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| 259. |
The root mean square speed of an ideal gas at constant pressure varies with density d as .A. `d^(2)`B. dC. `sqrt(d)`D. `1//sqrt(d)` |
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Answer» Correct Answer - d (d) Rate of diffusion `prop(1)/(sqrt("density"))` at constant P and T `d=(PM)/(RT)," " dpropM` |
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| 260. |
Calculate the pressure excerted by `5 mol` of `CO_(2)` in `1 L` vessel at `47^(@)C` using van der Waals equation. Also report the pressure of gas if it behaves ideally in nature. `(a=3.592 atm L^(2) mol^(-2), b=0.0427 L mol^(-1))` |
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Answer» Given `n =5, V =1 litre,` `T =47 + 273 = 320 K` ` a = 3.592, b = 0.0427` Using van ber Waals equation for n mole `[P+(n^(2)a)/(V^(2))][V -nb]=nRT` `[P +(25 ccxx 3.592)/(1)][1 -5 xx 0.0427]=5 xx 0.0821 xx 320` `P =77.218 atm` Also if gas behaves ideally, then `PV =nRT` ` P xx 1 =5 xx 0.0821 xx 320 = 131.36` atm . |
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| 261. |
The pressure and temperature of `4 dm^(3)` of carbon dioxide gas are doubled. Then the volume of carbon dioxide gas would beA. `2 dm^(3)`B. `3 dm^(3)`C. `4 dm^(3)`D. `8 dm^(3)` |
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Answer» Correct Answer - C `(P_(1)V_(1))/(T_(1))=(P_(2)V_(2))/(T_(2)), (P_(1)xx4)/(T_(1))=(2P_(1)xxV_(2))/(2T_(1))` `8 = 2 xx V_(2)` so `V_(2)= 4 dm^(3)` |
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| 262. |
Three balloons are filled with the same number of atoms of He, Ar and Xe, respectively. Which statement is true under the same conditions of temeprature and pressure?A. The balloons contain the same mass of gas.B. All balloons have the same volume.C. The densities of the three gases are the same.D. The average speed of the different types of atoms is the same. |
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Answer» Correct Answer - b |
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| 263. |
Ideal gas is defined as a gas whose molecules move independent of each other without any net force between them. Also molecules//atoms of ideal gas are assumed to be like point masses with negligible size. But real gas molecules have net force between them and have a finite size which may or may not be negligible. In the above given experiment if helium gas was used in both samples which sample would have greater final pressure?A. Ideal gasB. Real gasC. Equal in both samplesD. Cannot predict |
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Answer» Correct Answer - b |
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| 264. |
Ideal gas is defined as a gas whose molecules move independent of each other without any net force between them. Also molecules//atoms of ideal gas are assumed to be like point masses with negligible size. But real gas molecules have net force between them and have a finite size which may or may not be negligible. Two samples of `O_(2)` (g) having equal moles at 1 atm and `0^(@)` C are heated at constant volume to `27^(@)` C Assuming both samples are ideal at `0^(@)` C but at `27^(@)` C one is ideal and another is real which of the following is correct?A. Final pressure is more for real gasB. Final pressure is more for ideal gasC. Final pressure is equal in both casesD. Cannot predict |
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Answer» Correct Answer - b |
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| 265. |
For a non-ideal gas, the compressibility factor (Z) is defined as `Z=(PV_(m))/(RT),V_(m)`= molar volume Compressibility of an unknown gas at 600 K and `1.0` atm was found to be `1.2` Also, this gas was found to effuse `1.58` times slower than the pure methane gas under identical conditions Take `R=0.0821` L-atm-`mol^(-1)k^(-1)` Molar volume of the gas in the given experimental condition is:A. `41.0` LB. `39.4` LC. `59.1` LD. `27.3` L |
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Answer» Correct Answer - c |
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| 266. |
The density of neon will be highest atA. STPB. `0^(@)C`,2 atmC. `273^(@)C`, 1atmD. `273^(@)C`, 2 atm |
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Answer» Correct Answer - b |
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| 267. |
A gaseous mixture contains three gaseous `A,B` and `C` with a total number of moles of 10 and total pressure of `10 atm`. The partial pressure of `A` and `B` are `3 atm` and `1` atm respectively and if `C` has molecular weight of `2 g //mol`. Then, the weight of `C` present in the mixture will be `:`A. 6B. 8C. 12D. 3 |
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Answer» Correct Answer - c |
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| 268. |
1 mol of a gaseous aliphatic compound `C_nH_(3n)O_m` is completely burnt in an excess of oxygen. The contraction in volume in (assume water gets condensed out ):A. `(1+(1)/(2)n-(3)/(4)m)`B. `(1+(3)/(4)n-(1)/(4)m)`C. `(1+(1)/(2)n-(3)/(4)m)`D. `(1+(3)/(4)n-(1)/(2)m)` |
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Answer» Correct Answer - 4 `C_(n)H_(3n)O_(m)+yO_(2)rarrnCo_(2(g))+(3n)/(2)H_(2)O(l)` Contraction in volume `=` Contration in moles of gas `=1+(3n)/(4)-(m)/(3)=1+(3n)/(4)-(m)/(2)` `rArr " "(2n+(3n)/(2)-m)xx(1)/(2)=y" "rArr" "n+(3n)/(4)-(m)/(2)=y` |
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| 269. |
which of the following graphs correctly represents the vatiation `beta=-((dV)/(dP))_(T)//V` with `P` for an ideal gas at constant temperature ? .A. B. C. D. |
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Answer» From `PV = RT, dV.P = v. dP =0` or `((dV)/(dP))= -(V)/(P)` or `beta=((-dV)/(dP))_(T)//V=(1)/(P)` Thus plot of `beta` vs `P` given (a) . |
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| 270. |
Which of the following statements are correct?A. Helium diffuses at a rate 8.65 times as much as CO doesB. Helium escapes at a rate 2.65 times as fast as CO doesC. Helium escapes at a rate 4 times as fast as `CO_(2)` doesD. Heium escapes at a rate 4 times as fast as `SO_(2)` does |
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Answer» Correct Answer - d |
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| 271. |
Which of the following statements are correct ?A. It is not possible to compress a gas at a temperature below `T_(C)`B. At a temperature below `T_(C)` the molecules ar close enough for the attractive forces to act, and condensation occursC. No condensation takes place above `T_(C)`D. Due to higher kinetic energy of the gas molecules above `T_(C)`, it is considered as super critical fluid |
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Answer» Correct Answer - b,c,d (b,c,d) `T_(c)` is a temperature above which a gas can not be liquified at this point, slope of P - V curve is maximum and attraction force is dominating at this point. Both liquid vapour are exist in equilibrium. |
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| 272. |
A straight glass tube as shown, has 2 inleta X and Y at the two ends of 200 cm long tube. HCl gas through inlet X and `NH_(3)` gas through inlet Y are allowed to enter in the tube at the same time and pressure at a point P inside the tube. The distance of point P from X is:A. 118.9cmB. 81.1cmC. 91.1 cmD. 108.9cm |
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Answer» Correct Answer - b |
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| 273. |
At `27^(@)C` a sample of ammonia gas exerts a pressure of 5.3 atm. What is the pressure when the volume of the gas is reduced to one-tenth of the original value at the same temperature ?A. 0.53 atmB. 5.3atmC. 53 atmD. None of these |
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Answer» Correct Answer - c (c) `P_(1)V_(1)=P_(2)V_(2)` `V_(1)=V " , " V_(2)=(V)//(10)` |
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| 274. |
The rate of diffusion of a gas isA. Directly proportional to its densityB. Directly proportional to its molecular weightC. Directly proportional to the square root of its molecular weightD. Inversely proportional to the square root of its molecular weight |
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Answer» Correct Answer - D `(r_(1))/(r_(2))=sqrt((d_(2))/(d_(1)))=sqrt((M_(2))/(M_(1)))` |
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| 275. |
Which pair of gases will show same rate of diffusion at same pressure and temperature ? .A. `CO` and `N_(2)`B. `C_(2)H_(4)` and `CO`C. `B_(2)H_(6)` and `C_(2)H_(4)`D. All of these |
| Answer» Each pair of gas `(CO` and `N_(2),C_(2)H_(4))` and `CO , B_(2)H_(6)` and `C_(2)H_(4)` has same molecular mass . | |
| 276. |
Compounds of uranium-235 and uranium -238can be separated from one another by:A. distillationB. effusionC. fractional crystallizationD. paper chromatography |
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Answer» Correct Answer - b |
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| 277. |
The average veloctiy of an ideal gas molecule at `27^(@)C` is `0.3 m s^(-1)`. The average velocity at `927^(@)C` will beA. 0.6 `m//` secB. `0.3 m//` secC. `0.9 m // `secD. `3.0 m //` sec |
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Answer» Correct Answer - A `U_(av) =sqrt((8RT)/(piM)),{(T_(1)= 27+273=300K),(T_(2)=927+273=1200K):}}` `(U_(av_(1)))/(U_(av_(2)))=sqrt((T_(1))/(T_(2)))` or `(0.3)/(U_(av_(2)))=sqrt((300)/(1200))`or `(0.3)/(U_(av_(2)))=sqrt((1)/(4))` or `U_(av_(2))=0.6 m//`sec |
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| 278. |
A bottle of dry ammonia and a bottle of dry hydrogen chloride connected through a long tube are opened simultaneously at both ends. The white ammonium chloride ring first formed will beA. at the centre of the tubeB. near the ammonia bottleC. near the HCl bottleD. throughout the length of the tube. |
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Answer» Correct Answer - dc |
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| 279. |
Same mass of `CH_(4)` and `H_(2)` is taken in container. The partial pressure caused by `H_(2)` isA. `8 //9`B. `1//9`C. `1//2`D. 1 |
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Answer» Correct Answer - A `N_(CH_(4))=` number of moles of `CH_(4)=(m)/(16)` `N_(H_(2))= ` number of moles of `H_(2) = (m)/(2)` fraction partial pressure of `H_(2)` is `H_(2)=(n_(H_(2)))/(n_(H_(2))+n_(CH_(4)))=((m)/(2))/((m)/(2)+(m)/(16))=((m)/(2))/((9m)/(16))=(8)/(9)` |
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| 280. |
A certain hydrate has the formula `"MgSO"_(4).xH_(2)O`. A quantity of 54.2 g of the compound is heated in an oven to drive off the water. If the steam generated exerts a pressure of 24.8 atm in a 2.0 L container at `120^(@)C`, calculate `x`.A. 2B. 5C. 6D. 7 |
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Answer» Correct Answer - d (d) `n_(H_(2)O)=(PV)/(RT)=1.54` `(n_(MgSO_(4))xxH_(2)O)/n_(H_(2)O)=(1)/(x)=(54.2)/(120+18x)xx1.54` `x=7` |
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| 281. |
`3.06 L` of `H_(2)O` vapour is taken at a pressure of `1 atm` and `373 K` . It is now condensed to `H_(2)O(l)` at `300 K`. Calculate the approximate volume occupied by `H_(2)O(l) :` ( Assume density of liquid water at `300 K =1000 kg//m^(3))`A. `3.06L`B. `1.8mL`C. `1.8L`D. `3.06mL` |
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Answer» Correct Answer - 2 `PV=nRT` `=3.06xx1=nxx0.0821xx373` `n=0.1` mass of `H_(2)O_((vap))=1.8g` `rArr` Volume of `H_(2)O_((l))=1.8mL` |
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| 282. |
At very high pressure, the van der Waals equation reduces toA. `PV =RT -a//V`B. `PV =RT +Pb`C. `PV =RT`D. `PV =RT -a//V^(2)` |
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Answer» At high `P` the pressure correction is negligible as compared to total pressure `[P+(an.^(2))/(V^(2))](V-nb)=nRTas (an.^(2))/(V^(2)) lt lt lt P` `:.` For 1 mole of gas `P(V-b) =RT` `PV =RT +Pb` . |
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| 283. |
There are n connected having container having volume V, 2V,3V,...,nV separated by stopcock. All contaienr have same moles of gas at same temperature. If pressure of first contaienr is P, then final pressure when all stopcocks are opened is:A. `(np)/((n+1))`B. `(2p)/((n+1))`C. `(3p)/((n+1))`D. `(p)/(2(n+1))` |
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Answer» Correct Answer - b |
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| 284. |
A `V dm^(3)` flask contains gas `A` and another flask of `2V dm^(3)` contains gas `B` at the same temperature If density of gas `A` is `3.0gdm^(-3)` and of gas `B` is `1.5g dm^(-3)` and mo1 wt of `A =1//2` wt pf `B` then the ratio of pressure exerted by gases is .A. `(P_(A))/(P_(B))=2`B. `(P_(A))/(P_(B))=1`C. `(P_(A))/(P_(B))=4`D. `(P_(A))/(P_(B))=3` |
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Answer» Correct Answer - 3 Using `PV=(w)/(m)RT" "or" "P=(d)/(m)RT` For gas `A " "P_(A)=(3)/(m_(A))xxRxxT," "P_(a)=(1.5)/(m_(B))xxRxxT` `:. " "(P_(A))/(P_(B))=(2xxm_(B))/(m_(A))=(2xx2xxm_(A))/(m_(A))=4` |
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| 285. |
A `V dm^(3)` flask contains gas `A` and another flask of `2V dm^(3)` contains gas `B` at the same temperature If density of gas `A` is `3.0gdm^(-3)` and of gas `B` is `1.5g dm^(-3)` and mo1 wt of `A =1//2` wt pf `B` then the ration of pressure exerted by gases is .A. `(P_(A))/(P_(B)) =2`B. `(P_(A))/(P_(B)) =1`C. `(P_(A))/(P_(B)) =4`D. `(P_(A))/(P_(B)) =3` |
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Answer» Using `PV =(w)/(m) RT` or `P = (d)/(m) RT` For gas `A, P_(A) = (3)/(m_(A)) xx R xx T ` and `P_(B) = (1.5)/(m_(B)) xx R xx T` `:. (P_(A))/(P_(B)) = (2xxm_(B))/(m_(A)) = (2 xx 2 xx m_(A))/(m_(A)) =4` . |
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| 286. |
Which of the following is not the correct set of pressure and volume at constant temperature and constant moles of gas?A. `{:(P,V),(1atm,200mL):}`B. `{:(P,V),(760mm,0.2L):}`C. `{:(P,V),(0.5atm,100L):}`D. `{:(P,V),(2atm,100mL):}` |
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Answer» Correct Answer - c |
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| 287. |
Which of the following statements are incorrect .A. A mixture of ideal gases is cooled up to liquid to temperature `(4.22K)` to form ideal solutionB. Ideal gas can be liquefied on applying pressure and lowering temperature .C. Kinetic energy of a gas is zero at `0^(@)C` .D. Ideal gas on subsecting to Joule-Thomson effect do not show cooling an account of obsence of molecules forces of attraction . |
| Answer» Ideal gas does not show cooling or heating . | |
| 288. |
However great the pressure , a gas cannot be liquified above its :A. Boyle temperatureB. Inversion temperatureC. Critical temperatureD. Room temperature |
| Answer» Correct Answer - C | |
| 289. |
Just below this temperature gaases would theroretically have a negative volume (which is however not possible):A. absolute zeroB. `-100^(@)C`C. `100^(@)C`D. `100K` |
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Answer» Correct Answer - a |
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| 290. |
At constant volume, the temperature (in `.^(@)C`) of certain mass of a gas is increased by `20%`. The pressure of gas:A. will increase by 20%B. will increase by `(2000)/(273)%`C. will increase by `(20t)/(273+t)%` where `t^(@)C` is the initial temperature of gasD. will increase by `(20t)/(273+t)%`, where `t^(@)C` is the final temperature of gas |
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Answer» Correct Answer - c |
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| 291. |
At constant volume, for a fixed number of moles of a gas, the pressure of the gas increases with the rise in temperature due toA. increase in the average molecular speedB. decrease in rate of collision amongst moleculesC. increase in molecular attractionD. decrease in mean free path |
| Answer» Correct Answer - a | |
| 292. |
At a constant temperature what should be the percentage increase in pressure for a `10%` decrease in the volume of gas ? .A. `10%`B. `20%`C. `5%`D. `50%` |
| Answer» Correct Answer - a | |
| 293. |
At a constant temperature what should be the percentage increase in pressure for a `10%` decrease in the volume of gas ? .A. `10%`B. `20%`C. `55`D. `50%` |
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Answer» Use `PpropT,or (V_(1))/(V_(2))=(V_(1))/(V_(2))` If `V_(2) =[V_(1) -(10V_(1))/(100)]` Find `T_(2)` and calculate per cent change . |
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| 294. |
If `m_(1),m_(2)` are masses of an ideal gas, then which of the graph repersents `m_(2)gtm_(1)` ?.A. B. C. D. |
| Answer» Correct Answer - `PV =(m_(1))/(M)RT` | |
| 295. |
Select the incorrect statement(s).A. The compressibility factor (Z) for `H_(2)` and He is given by equation `: Z=1+(Pb)/(RT)`B. At critical temperature all real gases behave like and ideal gas.C. The compressibility factor for gas at critical state is `(8)/(3)`D. The rms velocity of ideal gas molecule will be doubled if pressure is made four times by decreasing the volume of container. |
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Answer» Correct Answer - bcd |
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| 296. |
Value of gas constant `R` is .A. 0.082 litre atm k^(-1) mole^(-1)B. `0.987 cal mol^(-1) K-1`C. `8.3 J mol^(-1) K-1`D. `83 cal mol^(-1) K-1` |
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Answer» `R =8.3 J mol^(-1) K^(-1) =2 cal mol^(-1) K^(-1)` ltbr gt`8.314 xx 10^(7) erg mol^(-1) K^(-1)` `=0.082` litre atm `K^(-1) mol^(-1)` . |
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| 297. |
The volume of a gas increases by a factor of 2 while the pressure decrease by a factor of 3 Given that the number of moles is unaffected, the factor by which the temperature changes is `:`A. `(3)/(2)`B. `3xx2`C. `(2)/(3)`D. `(1)/(2)xx3` |
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Answer» Correct Answer - c |
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| 298. |
Which of the following statements are incorrect?A. Molar volume of every gas at `STP is 22.4 L`B. Unde critical states compressibility factor is 1C. All gases will have equal value of average `KE` at a given temperatureD. At absolute zero, `KE` is `3//2 R`. |
| Answer» Correct Answer - A::B::D | |
| 299. |
On a ship sailing in pacific ocean, where temperature is `22^(@)C`, a balloon is filled with 2L air. What will be the voume of balloon when the ship reaches Indian ocean, where temperature is `27^(@)C`? The atmospheric pressure is same over pacific ocean and Indian ocean.A. 2LB. `(600)/(295)L`C. `(54)/(22)L`D. `(590)/(300)L` |
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Answer» Correct Answer - b |
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| 300. |
The rms speed of the molecules of a gas of density 4 kg `m^(-3)` and pressure `1.2xx10^(5) N m^(-2)` is:A. `120m s^(-1)`B. `300 m s^(-1)`C. `600m s^(-1)`D. `900 m s^(-1)` |
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Answer» Correct Answer - b |
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