InterviewSolution
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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.
| 1. |
What is the principle involved in the following methods of separation of mixtures ? (i) Fractional crystallization (ii) Magnetic separation (iii) Gravity method (iv) Separating funnel method (v) Distillation (vi) Fractional distillation (vii) Preferential liquifaction (viii) Chromatography (ix) Fractional evaporation |
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Answer» (i) Solubility of solids in a given solvent (ii) Magnetic nature of one component (iii) Density variations w.r.t. a given solvent (iv) Immiscible liquids (v) Soluble solid in a given liquid (vi) Difference in BP (vii) Ability of one of component of gas to liquify under high pressure (viii) Adsorption of components of a mixture (ix) Difference in BP of gases. |
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| 2. |
For the following properties listed below, arrange solids, liquids and gases either in the increasing or decreasing order as indicated against them. (i) Diffusibility (ii) Intermolecular spaces (iii) Thermal expansion (iv) Intermolecular force of attraction |
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Answer» (i) Increasing order: Solids, liquids, gases (ii) Decreasing order: Gases, liquids, solids (iii) Increasing order: Gas, liquids, solids (iv) Decreasing order: Solids, liquids, gases |
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| 3. |
Which of the following statements is true regarding solids?A. Solids are highly compressible.B. Solids diffuse rapidly.C. Solids possess low density.D. Solids possess many number of free surfaces. |
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Answer» Correct Answer - C::D Due to close packing of molecules in solids they possess definite shape due to which they have many number of free surfaces. |
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| 4. |
Explain the method by which `Cl_(4),H_(2)O` and ethyl alcohol mixture can be separated. |
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Answer» (i) Miscible and immiscible liquids. (ii) The separation of miscible and immiscible liquids (iii) Comparison of the physical properties of liquid. (iv) Suitable separation procedure based on physical properties |
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| 5. |
What is the method of separation of (a) `N_(2)-CO_(2)` mixture, (b) `H_(2) -O_(2)` mixture, (c ) `NH_(4)Cl, KCl` and sand mixture, (d) Ink-water mixture |
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Answer» (i) Suitable solvent. (ii) Molecular weight. (iii) Sublimation, suitable solvent. (iv) Suitable adsorbent |
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| 6. |
State the uses of the followign non-metals. (a) Oxygen (b) Chlorine (c ) Sulphur |
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Answer» (i) Respiration (ii) Bleaching action (iii) Fungicides |
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| 7. |
A, B, C, D are four gases. If the order of their critical temperature is as follows D lt B lt C lt A, which of the following gas has the highest boiling point?A. AB. BC. CD. D |
| Answer» Correct Answer - A::C | |
| 8. |
According to the kinetic molecular theory, explain the following. (a) Density of a solid is the highest. (b) Gases are highly compressible whereas solids are incompressible. (c ) Liquids and gases are fluids whereas solids are rigid. |
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Answer» (i) Intermolecular force of attraction. (ii) Intermolecular spaces. |
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| 9. |
What is supernatant liquid? |
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Answer» (i) Clear liquid formed (ii) Solid-liquid solution |
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| 10. |
What is the shape of the meniscus observed when water and mercury are taken in two different capillary tubes and why? |
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Answer» (i) Type of forces between Hg molecules and Hg-glass molecules. (ii) Type of forces between water molecules and water-glass molecules. (iii) Effect of these forces on the shape of meniscus. |
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| 11. |
Which of the following changes directly from solid to gas on heating?A. Ammonium chlorideB. Sodium chlorideC. Potassium chlorideD. Calcium chloride |
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Answer» Correct Answer - A::C Ammonium chloride is a sublimable substance which changes directly from solid to gas on heating. |
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| 12. |
Explain why the snow on ht mountain peaks does not melt at a temperature slightly above `0^(@)C`. |
| Answer» The atmospheric pressure on the mountain peaks is low. As ice contracts on melting, with the decrease in pressure its melting point increases. Thus, the snow does not melt slightly above `0^(@)C`. | |
| 13. |
The process of phase transition from solid to liquid involves the following steps. Arrange them in a proper sequence. (a) Molecules become free to move and thus attain molecular arrangement of liquid. (b) The energy supplied makes the molecules to vibrate more. (c ) During melting, the molecules overcome the forces of attraction between them. (d) the molecules acquire rotatory motion, translatory motion in addition to vibratory motion.A. c d a bB. b c d aC. c d b aD. None of these |
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Answer» Correct Answer - B::C (i) The energy supplied makes the molecules to vibrate with more speed. (ii) During melting, the molecules overcome the forces of attraction between them. (iii) The molecules acquire rotatory motion, translatory motion in addition to vibratory motion. (iv) Molecules become free to move and thus attain the molecular arrangement of a liquid. |
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| 14. |
Why do naphthalene and camphor sublime under normal conditions of temperature and pressure? |
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Answer» (i) High vapour pressure. (ii) The effect of high vapour pressure on sublimation. (iii) Comparison of the kinetic energy of surface molecules. |
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| 15. |
With the increase in pressure, the boiling point of the liquid _______. |
| Answer» Correct Answer - B::C | |
| 16. |
Silver tarnishes due to the formation of __________A. oxide layer.B. sulphide layer.C. nitride layer.D. hydride layer. |
| Answer» Correct Answer - B::C | |
| 17. |
_________ is used for making photographic films.A. `AgNO_(3)`B. `KNO_(2)`C. AgOD. AgCl |
| Answer» Correct Answer - C::D | |
| 18. |
A student is carrying out distillation process in the lab. Water is boiling in the distillation flask. Water that is collected in the receiver flask is refrigerated and ice cubes are formed. Ice cubes are then kept outside the refrigerator and they started melating. Arrange the following phases of water in the ascending order of their total (P.E + K.E) energy considering that the mass of water remains the same. (a) Water collected in the receiving flask. (b) Water boiling in the distillation flask. (c ) Steam passing through the delivery tube. (d) Ice cubes formed in the refrigerator.A. dcbaB. dabcC. cdbaD. dacb |
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Answer» Correct Answer - B::C d a b c (i) Ice cubes formed in the refrigeration (ii) Water collected in the receiving flask (iii) Water boiling in the distillation flask (iv) Steam passing through the delivery tube |
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| 19. |
For a certain purpose, a liquid having a liquid range from `- 10^(@)C " to " 110^(@)C` is required in large quantities. What is the suitable liquid for the above purpose and how can it be used? |
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Answer» (i) Liquid that has liquid range close to `-10^(@)C " to " 110^(@)C` (ii) Factors that affect melting and boiling points. (iii) Changes that can depress freezing point and clevate boiling point. |
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| 20. |
Brass is not suitable for type making becauseA. brass expands on solidification.B. brass contracts on solidification.C. brass has less tensile strength.D. brass has less ductility. |
| Answer» Correct Answer - B::C | |
| 21. |
Which among the pair is separated by using the principle of dissolution in suitable solvent?A. `SO_(2) and N_(2)O_(5),KOH` as solventB. `SO_(2) and NO_(2),KOH` as solventC. `SO_(2) and N_(2)O_(3), KOH` as solventD. `SO_(2) and NO,KOH` as solvent |
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Answer» Correct Answer - C::D Dissolution in suitable solvent is one of the method of separation of gas - gas mixture. As `SO_(2)` is acidic in nature it is dissolved in basic KOH where as NO is neutral it does not dissolved in KOH. So `SO_(2)` and NO are deparated. From the solution `SO_(2)` is separated by chemical means. |
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| 22. |
Skating on ice is almost impossible at very low temperatures say at arround `-30^(@)C`. Why? |
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Answer» Skating on ice is possible because as ice contracts on melting. So on applying pressure the melting point of ice decreases and the ice below the seates starts to melt and because of the formation of thin water film skating is possible on the ice But when temperature is arround `-30^(@)C` , the pressure exerted by body mass is not sufficient to melt the ice below the skates. Hence skating on ice is not possible at around `-30^(@)C`. |
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| 23. |
Discuss the change in energy and arrangement of molecules on increasing the temperature of ice from `=5^(@)C " to " 10^(@)C` at 1 atm pressure. |
| Answer» On heating ice at `-5^(@)C,` its temperature increases up to `0^(@)C,` i.e, the kinetic energy of the molecules increases. At `0^(@)C`, the ice starts to melt . During this period the energy supplied is taken up to increase the potential energy of the molecules and the arrangement of molecules changes. Once the ice cube melts, the heat energy supplied is again used to increase the temperature of water due to increase in kinetic energy of the molecules. However from `0^(@)C " to " 4^(@)C`, the molecules of water come closer and above `4^(@)C` the molecules move farther away. | |
| 24. |
Study the following graph and based on that answer the questions with suitable reason. The graph represents the various stages inveolved in step wise change of ice to steam. (a) Identify the stages associated with increase in temperature. Give reason. (b) In which stages, the temperature is constant? Why? |
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Answer» (a) In the graph, part 1 to 2,3 to 4 and 5 to 6 show heating of solid, liquid and gas respectively which increases kinetic energy and hence there is rise in temperature. (b) the parts, 2 to 3 and 4 to 5 represent melting of solid and boiling of liquid. At these points the heat energy supplied is utilized for decreasing the intermolecular force of attraction and hence there is no change in temperature |
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| 25. |
A mixture is formed by two kinds of matter, the molecules of which possess only vibratory motion. If the change in solubililty of two substances in a given solvent differs widely with the change in temperature, how can these two solids be separted from the solvent? |
| Answer» Solids possess the molecules which have only vibratory motion. Thus both the substances are solids. As their solubility in a particular solvent differs in a particular range of temperature, they can be separated by fractional crystallisation | |
| 26. |
Blue coloured `CuSO_(4)` solution is taken in a beaker. Is the blue solution an element compound or mixture? Is it homogeneous or heterogeneous? |
| Answer» Components present in the solution. | |