InterviewSolution
Saved Bookmarks
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.
| 1. |
1000 g of 1 molal aqueous solution of sucrose is cooled and maintained at `-3.534^(@)C`. Find out how much ice will separate out at this temperature. `(K_(f)` for water `=1.86 k m^(-1)`) |
| Answer» Correct Answer - `352.98 g` ; | |
| 2. |
Art what temperature `(s)` a `5%` solution `(w//V)` of glucose will develop an osmotic pressure of `7 atm`?A. `273 K`B. `306.94 K`C. `33.94^(@)C`D. `33.94 K` |
| Answer» Correct Answer - B::C | |
| 3. |
What will be the osmotic pressure of `0.1 M` monobasic acid its `pH` is `2` at `25^(@)C`? |
| Answer» Correct Answer - `2.69 atm` ; | |
| 4. |
Chloroacetic acid has `K_(a) = 1.36 xx 10^(-3)`. Calculate the concentration of each ion and freezing point of `0.1 M` its solution, assuming molarity and malality same. `(K_(f) "for"H_(2)O = 1.86 K "molality"^(-1))` |
| Answer» Correct Answer - `0.207^(@)C` | |
| 5. |
A solution containing 0.1 mol of naphthalene and 0.9 mol of benzene is cooled out until some benzene freezes out. The solution is then decanted off from the solid and warmed upto `353 K` where its vapour pressure was found to be `670 mm`. The freezing point and boiling point of benzene are `278.5 K` and `353 K` respectively, and its enthalpy of fusion is `10.67 KJ "mol"^(-1)`. Calculate the temperature to which the solution was cooled originally and the amount of benzene that must have frozen out. Assume ideal behaviour. |
| Answer» Correct Answer - `270.39 K, 12.14g`; | |
| 6. |
What is the ratio by weight of `NaF` and `NaI` which when dissolved in water produces the same osmotic effects as `0.1` molar solution of urea in water at same temperature? The weight of residue obtained on evaporation of the salt solution is `0.48` gram per `100mL` of solution evaporated. Assume complete dissociation of the salts. |
| Answer» Correct Answer - `0.28` ; | |
| 7. |
Among `0.1 M` solution of `NH_(2)CONH_(2), Na_(2)PO_(4)` and `Al_(2)(SO_(4))_(3)`:A. The `V.P.` and freezing point are the highest for urea.B. The elevation in boiling point is the highest for `Al_(2)(SO_(4))_(3)`C. The `V.P.` and freezing point is the lowest for ureaD. The depression in freezing point in the highest for the `Al_(2)(SO_(4))_(3)` |
| Answer» Correct Answer - A::B::D | |
| 8. |
The freezing point of `0.02` mole fraction acetic acid in benzene is `277.4 K`. Acetic acid exists partly as dimer. Calculate the equilibrium constant for dimerization. The freezing point of benzene is `278.4 K` and the heat the fusion of benzene is `10.042 kJ mol^(-1)`. Assume molarity and molality same. |
| Answer» Correct Answer - `3.39` ; | |
| 9. |
Vapour pressure of `C_(6)H_(6)` and `C_(7)H_(8)` mixture at `50^(circ)C` are given by `P=179X_(B)+92`, where `X_(B)` is mole fraction of `C_(6)H_(6)`. Calculate (in `mm`): (a) Vapour pressure of pure liquids. (b) Vapour pressure of liquid mixture obtained by mixing `936g C_(6)H_(6)` and `736g` toluene. ( c) If the vapours are removed and condensed into liquid and again brought to the temperature of `50^(circ)C`, what would be mole fraction of `C_(6)H_(6)` in vapour state ? |
|
Answer» Correct Answer - (a) `92 mm`, (b) `199.4 mm`, ( c) `0.815, 0.185, 0.928, 0.072`; |
|
| 10. |
An aqueous solution of an acid is so weak that it can be assumed to be practically unionised, boiled at `100.4^(circ)C`. `25 mL` of this solution was neutralised by `38.5 mL` of `1N` solution of `NaOH`. Calculate basicity of the acid if `K_(b)` for water is `0.52 K mol^(-1) kg`. Assume molality equal to molarity. |
| Answer» Correct Answer - `2` ; | |
| 11. |
If the boiling point of an aqueous solution is `100.1^(@)C`, what is its freezing point ? Given `l_(f)=80` ,` l_(v)=540 "cal" g^(-1)` respectively, of `H_(2)O`. |
| Answer» Correct Answer - `-0.362^(@)C` ; | |
| 12. |
`3.24 g` of sulphur dissolved in `40g` benzene, boiling point of the solution was higher than that of benzene by `0.081 K`. `K_(b)` for benzene is `2.53 K kg mol^(-1)`. If molecular formula of sulphur is `S_(n)`. Then find the value of `n`. (at.wt.of `S =32`). |
| Answer» Correct Answer - 8 | |
| 13. |
One mole of `(C_(6)H_(5))_(3)C.OH` dissolved in `1000g` of `100%` sulphuric acid lowers the freezing point of sulphuric acid twice as one mole of `CH_(3)OH` shows in `1000g` of `100%` sulphuric acid. Comment on it associated in sulphuric acid. |
| Answer» Correct Answer - `100%` dissociation ; | |
| 14. |
A certain mass of a substance when dissolved in `100 g C_(6)H_(6)` lowers the freezing point by `1.28^(circ)C`. The same mass of solute dissolved in `100 g` of water lowers of the freezing point by `1.40^(circ)C`. If the substance has normal molecular weight in benzene and is completely dissocited in water, into how many ions does it dissocite in water ? `K_(f)` for `H_(2)O` and `C _(6)H_(6)` are `1.86` and `5.12 K mol^(-1) kg` respectively. |
| Answer» Correct Answer - `3`; | |
| 15. |
Two elements `A` and `B` form compounds having molecular formula `AB_(2)` and `AB_(4)`. When dissolved in `20 g` of benzene, `1 g`of `AB_(2)` lowers the freezing point by `2.3 K`, whereas `1.0 g` of `AB_(4)` lowers it by `1.3 K`. The molar depression constant for benzene is `5.1 K kg mol^(-1)`. Calculate the atomic mass of `A` and `B`. |
| Answer» Correct Answer - At. wt. of `A = 25.59`, At. wt. of `B = 42.64` ; | |
| 16. |
A beaker containing `20 g` sugar in `100 g` water and another containing `10g` sugar in `100 g` water are placed under a bell-jar and allowed to stand until equilibrium is reached. How much water will be transferred from one beaker to other? |
| Answer» Correct Answer - `33.3 g`; | |
| 17. |
At `300 K`, two solutions of glucose in water of concentration `0.01M` and `0.01M` are separated by semipermeable membrane with respect to water. On which solution, the pressuer need be applied to prevent osmosis ? Calculate magnitude of this applied pressure. |
| Answer» Correct Answer - `0.01M, 0.2217 atm`; | |
| 18. |
The vapour pressure of water at `293 K` is `2338 Pa` and the vapour pressure of an aqueous solution is `2295.8 Pa`. If solution density is `1010 kg//m^(3)` at `313 K`, calculate the omotic pressure at `313 K`. (Molecular weight of solute `= 60`) |
| Answer» Correct Answer - `2.53 xx 10^(6) Pa` ; | |
| 19. |
A tube of uniform cross-sectional area `1 cm^(2)` is closed at one end with semi-permeable membrane. A solution of `5 g` glucose per `100 mL` is placed inside the tube and is dipped in pure water at `27^(@)C`. When equilibrium is established, calculate: a. The osmotic pressure of solution. b.The height developed in vertical column. Assume the density of final glucose solution `1 g mL^(-1)` |
| Answer» Correct Answer - (a) `6.842 atm`, (b) `70.43 m` ; | |
| 20. |
At `300 K`, the vapour pressure of an ideal solution containing one mole of `A` and `3` mole of `B` is `550 mm` of `Hg`. At the same temperature, if one mole of `B` is added to this solution, the vapour pressure of solution increases by `10 mm` of `Hg`. Calculate the `V.P.` of `A` and `B` in their pure state. |
| Answer» Correct Answer - `V.P.` of `A = 400 mm`, `V.P.` of `B = 600 mm`; | |
| 21. |
A tube of uniform cross-sectional area `1 cm^(2)` is closed at one end with semi-permeable membrane. A solution of `5 g` glucose per `100 mL` is placed inside the tube and is dipped in pure water at `27^(@)C`. When equilibrium is established, calculate: a. The osmotic pressure of solution. b.The height developed in vertical column. Assume the density of final glucose solution `1 g mL^(-1)` |
| Answer» Correct Answer - (a) `6.842 atm`, (b) `70.43 m` ; | |
| 22. |
What weight of solute `(M. wt. 60)` is required to dissolve in `180 g` of water to reduce the vapour pressure to `4//5th` of pure water? |
| Answer» Correct Answer - `150 g`; | |
| 23. |
A `0.001` molal solution of a complex represented as `Pt(NH_(3))_(4)Cl_(4)` in water had freezing point depression of `0.0054^(@)C`. Given `K_(f)` for `H_(2)O=1.86 K m^(-1)`. Assuming `100%` ionization of the complex, write the ionization nature and formula or complex. |
| Answer» Correct Answer - `[Pt(NH_(3))_(4).Cl_(2)]Cl_(2)` ; | |