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.
| 601. |
The formula for glauber salt is ______. |
| Answer» Correct Answer - `Na_(2)SO_(4).10H_(2)O` | |
| 602. |
Why is pure water a bad conductor of electricity ? |
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Answer» (i) Property of water. (ii) Condition required for a substance to conduct electricity . (iii) Composition of pure water. |
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| 603. |
If Glauber salt, anhydrous calcium chloride, calcium oxide and concentrated `H_(2)SO_(4)` are kept in air light container A,B, C,D respectively , in which container pressure becomes more ?A. AB. BC. CD. D |
| Answer» Correct Answer - A::C | |
| 604. |
`Na_(2)CO_(3).10H_(2)O` on exposure to air loses some water of crystallization and the rest on heating . How do you account for the above phenomenon ? |
| Answer» `Na_(2)CO_(3).H_(2)O` on exposure to air loses nine water moleclues from its water of crystallization because initially vapour pressure of the compound is more than vapour pressure of the moisture present in the atmospheric air. It is an example of an efflorescent substance. After the release of nine molecules of water of crystallization its vapour pressure becomes equal to the pressure of the moisture present in atmosphere. Hence removal of 10th water molecule requires. | |
| 605. |
Amount of solutes A,B and C in 500 g of water at `30^(@)C ,60^(@)C , 100^(@)C ` in their saturated solutions are given below. `{:(,30^(@)C,60^(@)C,100^(@)C),(A,140 g, 135 g,131 g),(B,160 g, 175 g, 182 g ),(C,152 g, 170 g, 161 g):}` When the hot saturated solutions of A, B and C are cooled slowly, identify the order in which they crystallize out of a solution. Give reason in support of your answer. |
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Answer» (i) comparision of changes in soubilities with change in temperature. (ii) Comparision of change is solubilities with decrease in temperature from `100^(0)C` to `30^(0)C . (iii) Effect of cooling on nature of the solutions of A , B, C respectively. (iv) Relation between extent of solubility and crystallization. |
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| 606. |
Amount of solutes A,B,C,D and E in 1500 g of water at `25^(@)C` , `50^(@)C` and `75^(@)C` in their saturated solutions are given below `{:(,25^(@)C,50^(@)C,75^(@)C),(A,235 g , 280 g ,240 g ),(B,180 g , 190 g , 220 g),(C,160g ,170 g ,180g ),(D,175 g , 220 g , 200 g):}` Arrange the solutes in the increasing order of the amount of solutes that crystallises out by cooling from `75^(@)C ` to `25^(@)C`A. ABDCB. ACDBC. CABDD. ACBD |
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Answer» Correct Answer - B::C Amount of solutes A,B,C and D that crystallizes out are 5g , 40g, 20g and 25g respectively. |
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| 607. |
When water, containing equal amounts of `CO_(2), O_(2), NO_(2), N_(2)O_(3)` gases respectively , subjected to heating, which gas is evolved out in maximum precentage ? Give reason. |
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Answer» (i) Comparision of reactivity of gases with water. (ii) Conditions required for any gas to be present is maximum percentages in water. (iii) Relation between solubility of the gas and temperature. (iv) Effect of heating on rise in temperature on the gases present. |
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| 608. |
Why does water appear blue in deep waters, but transparent in shallow waters ? |
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Answer» (i) Nature of water molecules (ii) Relation between light absorbed /emitted/scattered and colour. (iii) Light absorbed/emitted by water. (iv) Comparsion of amount of light absorbed /emitted in deep waters and shallow waters. |
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| 609. |
Rain water and tap water are boiled in metallic containers A and B . The containers are emptied and then rain water samples are subjected to boiling in the same containers. In which case boiling gets delayed ? Give reason in support of your answer. |
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Answer» (i) Components present in rain water and tap water (ii) Effect of constituents on metallic containers due to boiling. (iii)Changes that takes place in metallic containers due to boiling. (iv) Changes that are observed with respect to boiling when rain water is again taken in containers. |
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| 610. |
Why does boiling of water expel the dissolved gases ? |
| Answer» As temperature increases the solubility of a gas in a liquid decreases. Hence boiling of water expels he dissolved gases. | |
| 611. |
Rain water does not leave any scales on boiling . Give reason. |
| Answer» Since the rain water is pure it does not have any dissolved salts present in it . So it does not leave any scales on boiling. | |
| 612. |
The specific heat capacity of water isA. `4.2 J kg^(-1)""^(@)C^(-1)`B. `4.2 J g^(-1)""^(@)C^(-1)`C. ` 1 J g^(-1)""^(@)C^(-1)`D. `1 J kg^(-1)""^(@)C^(-1)` |
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Answer» Correct Answer - B::C The specific heat capacity of water is `4.2 J g^(-10) C^(-1)` |
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| 613. |
What is the value of specific heat capacity of water ? How much heat energy is required to increase the temperature of 5 grams of water to `1^(@)C` ? |
| Answer» 4.2 Joule `g^(-1) ""^(@)c^(-1)`, 21 joule `g^(-1)""^(@)c^(-1)` | |
| 614. |
Will there be any change in the boiling point of water if we go to the top of a hill ? Give reasons. |
| Answer» Boiling point of water decreases. Reason is decreaes in pressure. | |
| 615. |
With respect to the saturation of a solution, what type of solution is aerated water ? Give reason in support of answer. |
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Answer» (i) Factors affecting the solubility of gases in water. (ii) Comparision of acrated water. (iii) Pressure condition in aerated water can. |
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| 616. |
The amount of solute `(H_(2)SO_(4))` and solvent present in a solution are 49 g and 90 g. respectively. If the specific gravities of the solute and solvent are 1.96 and 0.9, respectively, then calculate the molarity of the solution. |
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Answer» (i) determination of the volumes of the solute and solvent (ii) calculation of total volume of the solution (iii) calculation of number of moles of `H_(2)SO_(4)` (iv) calculation of molarity of solution |
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| 617. |
Which of the following metals is unsuitable for the preparation of hydratioi due to reversible reaction ?A. SodiumB. MagnesiumC. CopperD. Iron |
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Answer» Correct Answer - C::D Iron is unsuitable for the preparation of hydrogen due to reversible reaction. |
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| 618. |
Washing soda is an example of a/an _____ substance .A. efflorescentB. deliquescentC. hygroscopicD. Both (1) and (2) |
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Answer» Correct Answer - A::C Washing soda is an example of an efflorescent substance. |
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| 619. |
Which of the following compounds is not associated with water molecules ?A. Blue vitrolB. NitreC. Washing sodaD. Epsom salt |
| Answer» Correct Answer - B::C | |
| 620. |
When two substance A and B of same mass are heated under similar conditions number of free surfaces have been found to reduce to zero from one. If A maintains constancy in the temperature for a longer time than B during heating , thenA. Latent heat of fusion of A is more than that of B.B. latent heat of vapourisation of A is more than that of BC. latent heat of fusion of B is more than that of A.D. latent heat of vapourisation of B is more than that of A. |
| Answer» Correct Answer - B::C | |
| 621. |
Which among the following substance acts as a desiccating agent ?A. Anhydrous calcium chlorideB. Calcium oxideC. Hydrated copper sulphateD. Anhydrous sodium chloride |
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Answer» Correct Answer - B::C Calcium oxide acts as a desiccating agent. |
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| 622. |
Tyndal effect cannot be shown byA. smokeB. dust particles present in airC. fogD. iron powder in hydrochloric acid. |
| Answer» Correct Answer - C::D | |
| 623. |
Hydrogen acts as an oxidizing agent when itA. reacts with highly electropositive metalsB. burns in the presence of `O_(2)`C. forms ammonia when it reacts with nitrogenD. passes through boiling sulphur and forms `H_(2)S` gas |
| Answer» Correct Answer - A::C | |
| 624. |
Identify the binary solution among the following .A. SteelB. BronzeC. NichromeD. Gun metal |
| Answer» Correct Answer - C | |
| 625. |
The density of the particles of the dispersed phase is more than that of the dispersion medium in a colloid. But the colloid particles do not settle down. Give a reason. |
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Answer» (i) properties of colloid particles (ii) charge possessed by colloid particles (iii) forces acting between colloid particles (iv) effect of these forces against coagulation of colloid particles |
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| 626. |
A captain of ship will tell you that an iceberg is much bigger than it looks. Why is it so ? |
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Answer» Icebergs are the huge formation of water turned into ice, floating in the sea-water in the Arctic and Antarctic oceMerely, l/9th of the iceberg is visible above the water. The rest of the 8/9th is below the surface. Hence, an iceberg is very much bigger than it seems to be. |
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| 627. |
Which of the following properties of iceberg led to the sinking of the titanic ship?A. Heavy water currentsB. Relatively higher density of iceC. `9//10` of iceberg submerged below sea water and `1//10` above the sea waterD. None of the above |
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Answer» Correct Answer - C Icebergs weigh million of tons but float on the surface of sea water because the density of ice is less than that of the sea water. Usually `9//10` of icebergs will be below the surface of water and `1//10` above the sea water as a result we cannot estimate the size below water, and hence when ship hits this heavier ice berg the ship sinks. |
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