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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.
| 751. |
The activity of an enzyme becomes ineffectiveA. at low temperatureB. at atmospheric pressureC. at high temperatureD. in aqueous medium |
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Answer» Correct Answer - C Enzymes are effective only at optimum temperature . They becom ineffective at very high temperature . |
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| 752. |
A catalyst lowered the activation energy byh `25KJmol^(-1)` at `25^(@)C` . By how many times will the rate grow? |
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Answer» The rate of reaction is related to the activation energy by the following relation: `(K_(2))/(K_(1))=` Antilog `[(DeltaE)/(2.303RT)]` …(i) Given, `DeltaE=25xx10^(3)J` `R=8.314JK^(-1)mol^(-1)` `T=25^(@)C=298K` Substituting all the values in Eq. (i), we get `(K_(2))/(K_(1))=` Antilog `[(25xx10^(3))/(2.303xx8.314xx298)]=24069` `:. K_(2)=K_(1)xx24069` Therefore, the rate increases by `24069` times. The rate of reaction is related to the activation energy by the following relation: `(K_(2))/(K_(1))=` Antilog `[(DeltaE)/(2.303RT)]` …(i) Given, `DeltaE=25xx10^(3)J` `R=8.314JK^(-1)mol^(-1)` `T=25^(@)C=298K` Substituting all the values in Eq. (i), we get `(K_(2))/(K_(1))=` Antilog `[(25xx10^(3))/(2.303xx8.314xx298)]=24069` `:. K_(2)=K_(1)xx24069` Therefore, the rate increases by `24069` times. |
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| 753. |
The role of a catalyst in a reversble reaction is toA. Increase the rate of forward reactionB. Decrease the rate of backward reactionC. Alter the equilibrium constant of the reactionD. Allow the equilibrium to be achieved quickly |
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Answer» Correct Answer - D An increase in rate of reaction in forward direction by a catalyst for a reaction in equilibrium brings in an increase in concentration of products and thus rate fo backward reaction also increase to same magnitude and so allow the equilibrium to be achieved quickly. |
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| 754. |
Which of the following catalyses the conversion of glucose into ethanol?A. ZymaseB. InvertaseC. MaltaseD. Diastase |
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Answer» Correct Answer - A Zymase catalyst catalyses the conversion of glucose into ethanol. |
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| 755. |
Write any two characteristics of Chemisorption. |
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Answer» i) High specificity: Chemisorption is highly specific and it will only occur when adsorbent and adsorbate molecules can chemically react with each other. Eg. : oxygen is adsorbed on metals by oxide formation. ii) Surface area : Chemisorption increases with increase in surface area of the adsorbent. |
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| 756. |
the catalyst used in the contact process for manufacturing of sulphuric acid isA. CopperB. Iron//aluminium oxideC. Vanadium pentoxideD. Platinized asbestos |
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Answer» Correct Answer - C `underset(g)(2SO_(2))+underset(g)(O_(2))overset(V_(2)O_(5))(rarr)underset(g)(2SO_(3))` |
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| 757. |
Surface of the eye is protected from bacterial infection by the enzymeA. carbonic anhydrateB. ureaseC. lysozymeD. zymase |
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Answer» Correct Answer - C Lysozyme is the enzyme that protects the eye from bacterial infection . |
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| 758. |
The zeolites have shapes selectivity depending onA. pore structureB. atomic structureC. molecular structureD. None of the above . |
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Answer» Correct Answer - A The zeolites have shapes selectivity depending on pore structure . |
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| 759. |
Zeolites :A. Are microporous aluminosilicatesB. Have general formula `Mx//n[(AlO_(2))_(x)(SiO_(2))_(y)]m H_(2)O`C. Have pore size between 260 pm to 740 pmD. All |
| Answer» Correct Answer - D | |
| 760. |
The activity and selectivity of zeolites as catalyst is based on :-A. Their pore sizeB. Size of their cavities on the surfaceC. BothD. None |
| Answer» Correct Answer - C | |
| 761. |
Which of the following statements is incorrect?A. In a lyophilic sol, the presence of an electrolyte is not essential for stabilityB. Lyophilic sols are reversibleC. In Lyophobic sols, colloidal particles do not migrate in an electric fieldD. Ultramicroscopic imaging of lyophobic sols shows particles in motion |
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Answer» Correct Answer - C In lyophobic sols colloidal particules migrate in one direction in an electric help due to electeical charges An important charactersitic of lyophilic colloids is that if the dispersion medium is separated colloids is that if the disersion medium is separted from the dispersed phase say, by evaportion the sol can be reconstructed by simply remixing with the dispersion medium that is why these sols are also called reversible sols furthermore these sols are quite stable and cannot be easily coagulate |
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| 762. |
in which of following system the dispersed phase and dispersion medium are both solid ?A. foamB. Dust stormC. coloured glassD. Paints |
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Answer» Correct Answer - C Solid sol: Ruby glass (coloured glass) |
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| 763. |
which of the following is a hydrophilic colloidal sol?A. Barium hydroxide solB. Arsenic sulphide solC. Starch solutionD. Silver chloride sol |
| Answer» Correct Answer - C | |
| 764. |
Which one of the following is an example of a hydrophilic colloidal sol?A. Rubber in benzeneB. Rubber in waterC. Starch in alcoholD. `As_(2)S_(3)` in benezene. |
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Answer» Correct Answer - B Colloidal sol is directly formed when we mix rubber with water |
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| 765. |
Gelatin is generally added to ice creams. Why? |
| Answer» Ice cream is an emulsion of milk or cream in water, i.e., oil-in-water type. Gelatin is added to act as an emulsifier, i.e., it helps to stabilize the emulsion. Ice cream is an emulsion of milk or cream in water, i.e., oil-in-water type. Gelatin is added to act as an emulsifier, i.e., it helps to stabilize the emulsion. | |
| 766. |
which of the following is a hydrophilic colloidal sol?A. Barium sulphate sol.B. Arsenious sulphide sol.C. Starch sol.D. Silver iodide so. |
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Answer» Correct Answer - C Starch sol. Is example of hydrophilic sol. |
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| 767. |
What is the significance of reciprocal of "gold number"? |
| Answer» Smaller thegold number, greater is its protective power. Hence, the reciprocal of gold number is a direct measure of the protective power of the colloid. Smaller thegold number, greater is its protective power. Hence, the reciprocal of gold number is a direct measure of the protective power of the colloid. | |
| 768. |
size of colloidal particles may range from:A. `1 t o 1000 nm`B. `10 t o 1000 pm`C. `1 t o 1000 mum`D. `1 t o 10 mm` |
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Answer» Correct Answer - A Colloidal particles has size range of `1 t o 1000nm`. |
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| 769. |
idenify the correct statement regarding enzmes :A. Enzymes are specific biological catalysis that normally works at high temperautureB. Enzymes are normally heterogeneous catalysis which decrease the reaction rateC. Enzymes are specific biological catalysis with low molar massesD. Enzymes ae specific biological catalysis that are very specific in nature |
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Answer» Correct Answer - d |
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| 770. |
Tyndall effect is shown byA. Hydrophilic solsB. Hydrophiobic solsC. Starch solutionD. Both b and c |
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Answer» Correct Answer - B Tyndall effect is expressed by hydrophobic sols. |
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| 771. |
When dispersed phase is liquid and dispersion medium is gas, then the colloidal system is calledA. smokeB. cloudsC. emulsionD. jellies |
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Answer» Correct Answer - B `underset("liquid") ("dispersed phase")+underset("gas")("dispersion medium ")- underset("clouds")("Colloidal system")` . |
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| 772. |
Which of the following statements is not correct?A. A colloidal solution is a heterogeneous two-phase systemB. silver sol in water is an example of lyophilic solution.C. Metal hydroxide in water are example of lyophobic solutionD. Liquid - liquid colloidal solution in not a stable system |
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Answer» Correct Answer - B Silver sol in water is an example of lyophobic solution. |
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| 773. |
Lyophobic colloids are :A. Insoluble in waterB. In solution do not pass through filter paperC. Of definite size of particlesD. Separated from crystalloids by parchment paper |
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Answer» Correct Answer - D According to Graham, colloids are separated from crystalloids by parchment paper. |
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| 774. |
A liquid is found to scatter a beam of light but leaves no residue when passed through the filter paper.A. A suspensionB. oilC. A colloidal solD. True solution |
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Answer» Correct Answer - C Separation with filter paper not possible for colloidal solution. |
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| 775. |
A liquid is found to scatter a beam of light but leaves no residue when passed through filter paper. The liquid can be described asA. a suspensionB. OilC. a colloidal solD. a true solution |
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Answer» Correct Answer - C These are the properties of colloidal solution. |
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| 776. |
Which of the following statements is not correct?A. A colloidal solution is a heterogeneous two-phase system.B. Silver sol in water is an example of lyophilic solution.C. Metal hydroxides in water are examples of lyophobic solution.D. Liquid-liquid colloidal solution is not a stable system. |
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Answer» Correct Answer - B |
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| 777. |
In colloidal particles, the range of diameter is :A. 1 to 100 nmB. 1 to 1000 nmC. 1 to 100 cmD. 1 to 100m. |
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Answer» Correct Answer - B is the correct answer. |
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| 778. |
In colloidal particles, the range of diameter is :A. IncreasesB. DecreasesC. Remains unaffectedD. First increases then decreases |
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Answer» Correct Answer - A When a substance comes in colloidal state the surface area of the particles increases due to small size than substance. |
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| 779. |
A liquid is found to scatter a beam of light but leaves no residue when passed through the filter paper.A. a suspensionB. oilC. a colloidal solD. a true solution |
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Answer» Correct Answer - C |
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| 780. |
Give two examples of each `{:("(i) Aerosol" ," (ii) solid sol "),("(iii) Foam"," "):}` |
| Answer» `{:("(i) Smoke , dust" , " (ii) Pumice stone, foam rubber "),("(iii) Froth, soap lather",""):}` | |
| 781. |
size of colloidal particles may range from:A. 1 to 1000 nmB. 10 to 100 pmC. 1 to 100 `mum`D. 1 to 10 mm |
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Answer» Correct Answer - A |
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| 782. |
In neutralisation of KI by `AgNO_(3)` positive charge is due to adsorption ofA. `Ag^(+)` ionsB. AgC. I ionsD. Both (b) and (c) |
| Answer» Correct Answer - A | |
| 783. |
Size of colloidal particles isA. `0.1 m mu` to `0.001 m mu`B. `10 mu` to `20 mu`C. `0.05 m mu` to `0.1 m mu`D. `25 mu` to `30 mu` |
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Answer» Correct Answer - A The size of colloidal paricle is of the order `0.1 m mu` to `0.001 m mu`. |
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| 784. |
The viscosity of a liquid molecule depends on :A. Isothermic natureB. Solute-solute interactionC. Solute-solvent interactionD. Density of the liquid |
| Answer» Correct Answer - D | |
| 785. |
If `x` is the amount of adsorbate and `m` is the amount of absorbent, which of the following relation is not related to absorption process?A. `x/m = pxT`B. `x/m = f(p) " at constant " T`C. `x/m = f(T) " at constant " p`D. `p=f(T) " at constant " x/m` |
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Answer» Correct Answer - B At constant teperature , `T x/m prop p^(1//n)` Thus, `x/m=f(p) "at contant" T`. |
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| 786. |
The surface tension of a soap solution is `30xx10^(-3)Nm^(-1)`. The work done in stretching a bubble of this solution of surface area `5cmxx5cm`, to an area of `10cmxx10cm`, isA. `4.5xx10^(-4)J`B. `6.0xx10^(-4)J`C. `4.5xx10^(-5)J`D. `7.5xx10^(-4)J` |
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Answer» Correct Answer - A Work done. `=2(A_(2)-A_(1))xxS` `=2(10xx10-5xx5)xx10^(-4)m^(2)xx30xx10^(-3)Nm^(-1)` `=4.5xx10^(-5)J`. |
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| 787. |
Which one of the following is not a surfactant?A. `CH_(3)-(CH_(2))_(15)-overset(CH_(3))overset(|)underset(CH_(3))underset(|)(N^(+))-CH_(3)Br^(-)`B. `CH_3-(CH_2)_(14)-CH_2-NH_2`C. `CH_3-(CH_2)_(16)-CH_2OSO_2-Na^(+)`D. `OHC-(CH_2)_(14)-CH_2-COO-Na^(+)` |
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Answer» Correct Answer - B Surfactant are those which have charge on their tail e.g. cetyltrimethyl ammonium bromide. Surfactants are those, which dissociate in water to yield positively charge ion. so`CH_(3)(CH_2)_(14)-CH_(2)-NH_(2)` is not surfactant . |
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| 788. |
When the temperature is raise, the viscosity of liquid decreases, this is because,A. decreased volume of the solutionB. increases in temperature increases the average kintic energy of moleculeas, which overcome the attractive force between themC. Decreased covalent and hydrogen bond forceD. Increased attraction between molecules |
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Answer» Correct Answer - B When the temperature is raised, the viscosity of liquid decrease, this is because increasing in temperature increases the average kinetic energy of molecules which overcome the affractive force between them. |
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| 789. |
Which of the following characteristic is not correct for physical adsorption?A. Adsorption increases with increase in temperatureB. Adsorption is spontaneousC. Both enthalpy and entropy of adsorption are negativeD. Adsorption on solids is reversible |
| Answer» Correct Answer - 1 | |
| 790. |
Which is not colloidal?A. ChloropyllB. EggC. Ruby glassD. Milk |
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Answer» Correct Answer - A Egg is a colloid of solid and liquid, Ruby glass is a colloid of solid and solid. Milk is a colloid of liquid and liquid byt chlorophyll is a complex of magnesium. |
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| 791. |
Animal charcola is used in decolourising colour of liquids because it is a goodA. AdsorbateB. AdsorbentC. Oxidising agentD. Reducing agent |
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Answer» Correct Answer - B Animal charcoal is a good adsorbent. The impurities adsorbs on its surface and thus it decolourises coluor of liquids. |
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| 792. |
Surface tension of lyophilic sol isA. Lower than that of `H_(2)O`B. More than that of `H_(2)O`C. Equal to that of `H_(2)O`D. None of these |
| Answer» Correct Answer - 1 | |
| 793. |
Point out the false statementA. Browninan movement and Tyndall effect is shown by colloidal systemB. Gold number is a measure o the protective power of a lyophilic colloidC. The colloidal solution of a liquid in liquid is called gelD. Hardy-Schulze rule is related with coagulation |
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Answer» Correct Answer - C The colloidal solution of liquid is liquid is called emulsion not gel. |
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| 794. |
Which one of the following is an incorrect statement for physisorption ?A. it is a reversible processB. It requries less heat of adsoptionC. it requires activation energyD. It takes place at low temperature |
| Answer» Correct Answer - 3 | |
| 795. |
Which one of the following is an incorrect statement for physisorptionA. It is a reversible processB. It requires less heat of absorptionC. it requires activation energyD. it takes place at low temperature |
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Answer» Correct Answer - C Physisorption is a process in which the particles of adsobate are held to the surface of adsorbent by physical force hence does not requires activation energy . |
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| 796. |
Noble gases are adsorbed byA. Anhydrous calcium chlorideB. ferric hydroxideC. Conc. `H_(2)SO_(4)`D. Activated coconut charcol |
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Answer» Correct Answer - D Noble gases are adsorbed by coconut charcoal. The adsorption of different noble gases occur at different temperatures, hence charcoal is used to separate these gases. Helium is not adsorbed by charcoal (as it is very difficult liquifiable gas). |
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| 797. |
Which one of the following is an incorrect statement for physisorptionA. It is a reversible processB. It requires less heat of adsorptionC. It requires activation energyD. It takes place at low temperature |
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Answer» Correct Answer - C Physisorption is a process in which the particles of adsorbate are held to the surface of adsorbent by physical forces hence does not requires activation energy. |
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| 798. |
Which of the following options is / are correct with respect to catalysis / catalyst?A. Zeolites acts as good shape-selective catalyst because of their honeycomb-like structure.B. The modern adsorption theory for heterogeneous catalysts can explain action of catalytic promoters and catalytic poisons.C. Catalytic action is highly selective.D. Mixture of enzyme catalyst in water will show Tyndall effect. |
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Answer» Correct Answer - A::C |
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| 799. |
Identify the statements which are not correct.A. Soap sol of sodium palmitate will be coagulated near cathode on electrophoresis.B. If on adding electrolyte in an emulsion conductivity decreases it should be an oil in water emulsion.C. Macromolecular colloids are generally lyophilic.D. A promotor when taken without catalyst cannot change rate of reaction. |
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Answer» Correct Answer - A::B |
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| 800. |
Identify the option(s) which is/are incorrect with respect to adsorption.A. During adsorption there will be an increase in residual forces on the molecules.B. The extent of adsorption per unit mass of adsorbent will remain same even on changing surface are of same mass of adsorbent.C. When equilibrium is attained in adsorption then due to adsorption of gas at equilibrium, entropy of system and entropy of surrounding both increase by the same amount.D. Adsorption of gas on a solid surface is an entropy driven process. |
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Answer» Correct Answer - A::B::C::D |
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