InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your Class 11 knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Assertion (A): The Joules -Thomon coefficient for an ideal gas is zero. Reason (R ) : There are no intermlecular attactive forces in an ideal gas.A. If both the statement are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1B. If both the statement are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1C. If STATEMENT-1 is TRUE and STATEMENT-2 is FALSED. If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE |
| Answer» Correct Answer - A | |
| 2. |
A tightly sealed `25.0` litre acetone drum was found to have `15.4` litre acetone (l) at `780mm` hg pressure and `18^(@)C` Sudddenly during transportaion the drum was dented and its internal volume was found th decrease by `4.6` litre If vapour pressure of acetone at `18^(@)C` is `400mm` of Hg calculate the pressure inside the drum after denting . |
| Answer» Correct Answer - `1129.6 mm` | |
| 3. |
0.5 L of evacuated container is filled by gas upto 1 atm exactly, by connecting it to 20 litre cylinder initially at 1.2 atm. How many evacuated containers can be filled ? |
| Answer» Correct Answer - 8<br> | |
| 4. |
A vessel containing water is put in a dry sealed room of volume `76 m^(3)` at `15^(@)C` The saturation vapour pressure of water is 15 mm of Hg at `15^(@)C` How much water will evaportate before the water is in equilibrium with the vapour ? . |
| Answer» Water vapour will attain equilibrium when vapour pressure room becomes 15 mm at `15^(@)C`<br> or ` w = (PVm)/(RT) = (15 xx 76xx 10^(3) xx 18)/(760 xx 0.0821 xx 288)`<br> `= 1141 .90g = 1.1.42 kg`<br> Thus water evaporated is `1.142 kg` . | |
| 5. |
A desiccator of internal volume one litre containing `N_(2)` at 1 atm is partially evacuated to final pressure of `78mm` of Hg while `T` remains constant What is the volume of gas at this stage ? (b) A lungful of air `(3.55 cm^(3))` is exhaled into a machine that measures lung capcity if the air is exhaled from lungs at a pressure of `1.08` atm at `37^(@)C` but the machine is a ambient conditions of `0.958` atm and `23^(@)C` what is the volume of air measured by the machine ? . |
| Answer» The volume of vessel remains constant and some moles are given out<br> Thus given gas =1litre<br> `PV = nRT`<br> In lungs ` 1.08 xx (3.55)/(1000) = n xx 0.0821 xx 310`<br> In machine `0.958 xx V = n xx 0.0821 xx 296`<br> `:. V = 3.82 xx 10^(-3)` litre . | |
| 6. |
Density of methane , at `250^(@)C` and 6 atm pressure, is `[R=0.0821 atm ] :`A. `2.236 g//L`B. `8 g//L`C. `12 g//L`D. `16 g //L` |
| Answer» Correct Answer - 1<br>`d=(PM)/(RT)=(6xx16)/(0.0821xx523)=2.236` | |
| 7. |
6 litres of `H_(2)O` is placed in a closed room of volume 827 litre and temperature at 300K if vapour pressure of liquid water is `22.8` mm of Hg at 300K and its density is ` 1gm//cm^(3)` Then: [Given R=0.0821 `L-atm//mole-K` assuming volume of liquid water to be constant] `{:(,"Column-I",,"Column-II"),("(P)","Mass of "H_(2)O" in gaseous state "(gm),,(1)1/2),("(Q)","Moles of "H_(2)O" in gaseous state "("in moles"),,(2)18),("(R)","Total number of moles of oxygen gas that can be obtained from vapour form of "H_(2)O,,(3)3),("(S)","Total number of moles of all atoms from water in vapour form",,(4)1):}`A. `{:("P Q R S"),("1 2 4 3"):}`B. `{:("P Q R S"),("4 3 2 1"):}`C. `{:("P Q R S"),("2 4 1 3"):}`D. `{:("P Q R S"),("1 2 3 4"):}` |
| Answer» Correct Answer - (c)<br> | |
| 8. |
Calculate the weight of `N_(2)` in `6.24` litre cylinder at `27^(@)C` and `750 mm hg` `(R =0.0821` litre atm `K^(-1) mol^(-1))` . |
| Answer» Correct Answer - 7<br>Given `V =6.24 litre, P = (750)/(760)atm`<br> `T = 27 + 273 = 300K, m = 28`<br> Now `PV = (w)/(m0RT)`<br> `:. W = (PVm)/(RT) = (750 xx 6.24 xx 28)/(760 xx 0.0821 xx 300) =7g` . | |
| 9. |
On litre flask contains air, water vapour and a small amount of liquid water at a pressure of 200 mm Hg. If this is connected to another one litre evacuated flask, what will be the final pressure of the gas mixture at equilibrium ? Assume `T = 50^(@)C`, aqueous tension at `50^(@)C` is 93 mm Hg. Give answer excluding the decimal places. |
| Answer» Correct Answer - 146<br> | |
| 10. |
A flask contains a mixture of Ne(g) and Ar(g). There are 0.250 mol of Ne(g) which exerts a pressure of 205 mm Hg. If the Ar(g) exerts a pressure of 492 mmHg, what mass pf Ar(g) is in the flask? (Ar=40)A. 4.16gB. 12.1gC. 24.0gD. 95.9g |
| Answer» Correct Answer - c<br> | |
| 11. |
A flask containing air at `107^(@)C` and 722 mm of Hg is cooled to 100 K and 760 mm of Hg. If density in the initial condition `1g//cm^(3)`, then what is the final density `(g//cm^(3))`? |
| Answer» Correct Answer - 4<br>`P_(i)=722mm " "P_(f)=760mm`<br> `T_(i)=107+273=380 K " "T_(f)=100K`<br> `d_(i)=1_(g)//cm^(3) " "d_(f)=?`<br> `(d_(i)T_(i)R)/(P_(i))=(d_(f)T_(f)R)/(P_(f))`<br> `implies d_(f)=((P_(f))/(P_(i)))((T_(i))/(T_(f)))d_(i)=((760)/(722))((380)/(100))xx1g//cm^(3)`<br> `=4g//cm^(3)` | |
| 12. |
For 10 minutes each, at `0^(@)C`, from two identical holes nitrogen and an unknown gas are leaked into a common vessel of 4 litre capacity. The resulting pressure is 2.8 atm and the mixture contains 0.4 mole of nitrogen. What is the molar mass of unknown gas ? (Take `R = 0.821 "L-atm mol"^(-1)K^(-1)`] |
| Answer» Correct Answer - `0448`<br> | |
| 13. |
The prssure in bulb dropped from 2000 to 1500 mm of Hg in 47 minutes when the contained `O_(2)` leaked through a small hole. The bulb was then completely evacuated A mixture of `O_(2)` and another gas of mol wt 79 in the molar ratio 1:1 at a total pressure of 4000 mm of Hg was introduced Find the mole ratio of two gases remaining in the bulb after a period of 74 minutes . |
| Answer» Correct Answer - 0.00071048611111111 | |
| 14. |
A lighter gas diffuses more rapidly than a heavier gas At a given temperature the rate of diffusion of a gas is inversely proportional to the square root of its density . |
| Answer» Rate of diffusion `prop sqrt((1)/(M))` . | |
| 15. |
The pressure in vessel that contained pure oxygen dropped from 2000 torr to 1500 torr in 40 min as the oxygen leaked through a small hole into a vacuum. When the same vessel was filled with another gas, the pressure dropped from 2000 torr to 1500 torr in 80 min. What is the molecular weight of the second gas ? |
| Answer» Correct Answer - `0128`<br> | |
| 16. |
For 10 minutes each, at `0^(@)C`, from two identical holes nitrogen and an unknown gas are leaked into a common vessel of 4 litre capacity. The resulting pressure is 2.8 atm and the mixture contains 0.4 mole of nitrogen. What is the molar mass of unknown gas ? (Take `R = 0.821 "L-atm mol"^(-1)K^(-1)`]A. 448 g `"mol"^(-1)`B. `224 g "mol"^(-1)`C. 226 g `"mol"^(-1)`D. None of these |
| Answer» Correct Answer - a<br> | |
| 17. |
A sample of `H_(2)` is collected over `H_(2)O` at `23^(@)C` and a pressure of 732 mm Hg has a volume of 245mL what volume would the dry `H_(2)` occupy of `0^(@)C` and 1 atm pressure? [VP of `H_(2)O` at `23^(@)C`=21 mm Hg]A. 211mLB. 218mLC. 224mLD. 249mL |
| Answer» Correct Answer - a<br> | |
| 18. |
Volume of the air that will be expelled from a vessel of `300 cm^(3)` when it is heated from `27^(@)C` to `37^(@) C` at the same pressure will beA. `"310 cm"^(3)`B. `"290 cm"^(3)`C. `"10 cm"^(3)`D. `"37 cm"^(3)` |
| Answer» Correct Answer - c<br>(c) `V prop T`<br> Because temperature`uarr` by 10K<br> expelled air ` 10cm^(3)` | |
| 19. |
Dimethyl ether decomposes as `CH_(3)OCH_(3)(g)rarrCH_(4)(g)+CO(g)+H_(2)(g)` When `CH_(3)OCH_(3)(g)` decomposes to 20% extent under certain conditions, what is the ratio of diffusion of pure `CH_(3)OCH_(3)(g)` with methane?A. `0.59:1`B. `1.18:1`C. `2.36:1`D. `1.77:1` |
| Answer» Correct Answer - c<br>(c) `(r_(CH_(3)OCH_(3)))/(r_(CH_(4)))=sqrt((M_(CH_(4)))/(M_(CH_(3)OCH_(3))))xx(P_(CH_(3)OCH_(3)))/(P_(CH_(4)))`<br> `=sqrt((16)/(46))xx(0.8)/(0.2)=2.36:1` | |
| 20. |
A gas obeys `P(V-b) =RT` Select the correct statement about this gas .A. Isochoric curves have slope `=(R )/(V-b)`B. Isochoric curves have slope `(R )/(P)` and intercept b.C. For the gas compressibility factor ` =1+(Pb)/(RT)`D. The attraction forces are overcome by repulsive forces |
| Answer» `P(V -b) =RT`<br> `:. P =(R xx T)/((V-b)) ,Slope = (R)/((V-b))`<br> `PV -Pb = RT`<br> `V = (RT)/(P) +b, Slope = (R ) /(P)` and intercept `b`<br> ` Z = (PV)/(RT) = 1 + (Pb)/(RT)`<br> `Z gt1` repulsive forces predominates . | |
| 21. |
To an evacuated vessel with movable piston under external pressure of 1 atm 0.1 mole of He and 1.0 mole of an unknown compound vapour pressure 0.68 atm at `0^(@)C` are introduced Considering the ideal gas behaviour the total volume (in litre) of the gases at `0^(@)C` is close to . |
| Answer» Correct Answer - 7<br>For any ideal gas `PV =nRT`<br> For `He, n = 0.1 P =0.32` atm `V =? T =273`<br> `0.32 xx V =0.1 xx 0.0821 xx 273`<br> `V =7litre`<br> (unknown compound will not follow ideal gas equation) . | |
| 22. |
STATEMENT-1 : Reacting gases react to form a new gas having pressure equal to the sum of their partial pressure. STATEMENT-2 : Pressure exerted by a mixture of non-reacting gases present in a container is equal to the sum of their partial pressures.A. If both the statement are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1B. If both the statement are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1C. If STATEMENT-1 is TRUE and STATEMENT-2 is FALSED. If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE |
| Answer» Correct Answer - D | |
| 23. |
STATEMENT-1 : `1//4^(th)` of the initial mole of the air is expelled, if air present in an open vessel is heated from `27^(@)C` to `127^(@)C`. STATEMENT-2 : Rate of diffusion of a gas is inversely proportional to the square root of its molecular mass.A. If both the statement are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1B. If both the statement are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1C. If STATEMENT-1 is TRUE and STATEMENT-2 is FALSED. If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE |
| Answer» Correct Answer - B | |
| 24. |
STATEMENT-1 : 1 mol of `H_(2)` and `O_(2)` each occupy 22.7 L of volume at `0^(@)C` and 1 bar pressure, considering ideal behaviour. STATEMENT-2 : Molar volume for all ideal gases at the same temperature and pressure are equal.A. If both the statement are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1B. If both the statement are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1C. If STATEMENT-1 is TRUE and STATEMENT-2 is FALSED. If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE |
| Answer» Correct Answer - A | |
| 25. |
Which of the following parameteres would be expected to have the same values for `C_(2)H_(5)OH` and `CH_(3)OCH_(3)`?A. Heat of vaporizationB. Vapour pressure at the same temperatureC. Boiling pointsD. Gaseous denitites at the same temperature and pressure (Assuming ideal behaviour) |
| Answer» Correct Answer - d<br> | |
| 26. |
A sample of oxygen gas and a sample of an unknown gas are weighed separately in the same evacuated flask. Use thedata given below to find the molar mass of the unknown gas (assume experiments are carried out at the same pressure and temperature). `|:(" Mass of evacuted flask",,124.46 g),(" Mass of flask+oxygen",,125.10g),("Mass of flask+unknown gas",,125.34 g):|`A. 22 g/molB. 38g/molC. 44g/molD. 84g/mol |
| Answer» Correct Answer - c<br> | |
| 27. |
Value of gas constant `R` is .A. 0.082 litre-atmB. 0.987 cal `"mol"^(-1)K^(-1)`C. 8.3J `"mol"^(-1)K^(-1)`D. 83 erg `"mol"^(-1)K^(-1)` |
| Answer» Correct Answer - c<br> | |
| 28. |
The Maxwell-Boltzmann distribution law of molecular speeds is graphically represented as The curve has which of the following characteristics ?.A. It has symmerical distributionB. The point `A` on X-axis reperesents the most probable speedC. The area under the curve gives the total number of moleculesD. The maxium shifts to the right as the temerature increase |
| Answer» Follow maxwell distribution curve | |
| 29. |
Which of the following statement about Maxwell Boltzmann law of distribution of molecular speeds is//are correct ?.A. The fraction of molecules having speed between c and `(c +dc)` (regardles of direction) is given by `4pi((M)/(2piRT))^(3//2)c^(2) exp((-Mc^(2))/(2RT))dc` .B. The average speed is the arithmetic mean of the differnet speeds of all the molecules present in a given sample of the gas .C. The speed distribution curve becomes sharper and is more peaked at higher temperature as the average speed increases .D. The speed distribution function is used to determine average molecular speeds . |
| Answer» The increase in temperature flattens the peak . | |