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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.
| 901. |
Adsorption of gases on solid surface is generally exothermic becauseA. Enthalpy is positiveB. Entropy decreasesC. Entropy increasesD. Free energy increase |
| Answer» Correct Answer - 2 | |
| 902. |
The physical adsorption of gases on the solid surface is due to :A. vander Waals forcesB. covalent bondingC. hydrogen bondingD. All of these |
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Answer» Correct Answer - A Physical adsorption is due to vander waals forces. |
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| 903. |
Which of the following can act as protective colloids?A. Hydrophobic solB. hydrophilic solC. Gold solD. None of these |
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Answer» Correct Answer - B Hydrophilic sol can act as protective colloids for hydrophobic solution. |
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| 904. |
Select the only incorrect option for gold sol.A. (II) (ii) (P)B. (II) (iii) (S)C. (III) (iv) (S)D. (II) (iii) (Q) |
| Answer» Correct Answer - D | |
| 905. |
Which of the following characteristics is not correct for physical adsorption ?A. Monomolecular layer forms on the adserbentB. Adsorption increases with increase in temperatureC. Adsorption is spontaneousD. Both enthalpy and entropy of adsorption are negative |
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Answer» Correct Answer - A::B (ab) (a) Multilayer is formed during physical adsorption. (b) Adsorption decreases with increase in temperature. |
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| 906. |
When 9.0 ml of arsenius sulphide sol and 1.0 ml of `1.0 xx 10^(-4) M BaCl_(2)` are mixed, turbidity due to precipitation just appears after 2 hours. Find the coagulating value of the effective ion. |
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Answer» Correct Answer - `Ba^(2+), 10 m` mol/L Conc. Of `Ba^(2+) = (10^(-4))/(10 xx 10^(-3)) M = 10^(-2) M = 10` mmole/L. |
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| 907. |
Which of the following statements is/are correct?A. The efficiency of a heterogeneous catalyst depends upon its surface area.B. Catalyst operates by providing alternate path for the reaction that involves a lower activation energy.C. Catalyst lowers the energy of activation of the forward direction without affecting the energy of activation of the backward direction.D. Catalyst does not affect the overall enthalpy change of the reaction. |
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Answer» Correct Answer - A::B::D |
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| 908. |
Which of the following statement is not correct:-A. The extent of adsorption depends on the natrue of the adsorbent and adsorbateB. The extent of adsorption depends on the pressure of the gasC. The extent of adsorption depends on the temperatureD. The extent of adsorption has no upper limit |
| Answer» Correct Answer - D | |
| 909. |
Specific surface area of a solid adsorbent is the surface area of the unit mass of the adsorbent. For any adsorbent, the specific surface area may be increased by taking the adsorbent in powdered form or by increasing the pores in the solid. `112 cm^(3)` hydrogen gas is adsorbed uniformly at the surface of 5 gm palladium at `273^(@)C` and 2 atm. If the effective surface area of each hydrogen molecule is `0.4 nm^(2)`, then the specific surface area of palladium is : [Take : `N_(A) = 6x10^(23)`]A. `1.2xx10^(7)cm^(2)//gm`B. `2.4xx10^(6)cm^(2)//gm`C. `6.0xx10^(7)cm^(2)//gm`D. `0.6xx10^(6)cm^(2)//gm` |
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Answer» Correct Answer - B |
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| 910. |
Which one of the following is/are correct statement for physisorptionA. It is a reversible process.B. It requires less heat of adsorption.C. It requires activation energy.D. It takes place at low temperature. |
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Answer» Correct Answer - A::B::D Physisorption does not require activtion energy. Correct Answer - A::B::D Physisorption does not require activtion energy. |
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| 911. |
Choose the correct statement(s).A. When the reactants and the catalyst are in the same phase (i.e, liquid or gas), the process is said to homogeneous catalysis.B. Oxidation of `Na_(2)SO_(3)` in presence of `Na_(3)AsO_(3)` in excess of air is an example of induced catalysis.C. Ester hydrolysis (in acidic medium) is slow in the beginning and becomes faster after some time.D. (Metal ions) when weakly bonded to enzyme molecules decrease their catalytic activity. |
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Answer» Correct Answer - A::B::C |
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| 912. |
Which of the following is/are not correctly matched?A. Emulsion-curdB. Foam-mistC. Aerosol-smokeD. Solid sol-cake |
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Answer» Correct Answer - A::B::D Smoke is an aerosol (solid carbon particles dispersed in air). Correct Answer - A::B::D Smoke is an aerosol (solid carbon particles dispersed in air). |
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| 913. |
Specific surface area of a solid adsorbent is the surface area of the unit mass of the adsorbent. For any adsorbent, the specific surface area may be increased by taking the adsorbent in powdered form or by increasing the pores in the solid. If unit mass of a solid, taken as cube of volume 8 `cm^(3)`, is powdered into identical `10^(12)` cubes, then the specific surface area of the solid increased by :A. `10^(12)` timesB. `10^(8)` timesC. `10^(4)` timesD. `10^(-8)` times |
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Answer» Correct Answer - C |
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| 914. |
For is an example ofA. solid dispersed in gasB. Liquid dispersed in gasC. Liquid dispersed in solidD. Solid dispersed in liquid. |
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Answer» Correct Answer - B Fog is an example of liquid dispersed in gas ie., moisture (liquid droplets) is dispersed in air. |
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| 915. |
Which of the following statements is/are correct ?A. Physical adsorption is multilayer, non-directional, and non-specific.B. On some cases, solvent may be adsorbed in preference to the solute on the surface of the adsorbent.C. Chemical adsorption increases with increases in temperature.D. Due to adsorption, surface energy increases. |
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Answer» Correct Answer - A::B (c) is wrong because chemical adsorption first increases and then decreases with increase in temperature. (d) is wrong because as a result of adsorption, there is a decreases in surface energy. Correct Answer - A::B (c) is wrong because chemical adsorption first increases and then decreases with increase in temperature. (d) is wrong because as a result of adsorption, there is a decreases in surface energy. |
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| 916. |
Which of the following is/are lyphobic colloids?A. gold solB. `As_(2)S_(3)` solC. `Fe(OH)_(3)` solD. Starch sol |
| Answer» Correct Answer - A::B::CCorrect Answer - A::B::C | |
| 917. |
Liquid-Liquid sol is known asA. aerosolB. foamC. emulsionD. gel |
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Answer» Correct Answer - C Emulsion is liquid in liquid sol. |
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| 918. |
Which of the following increase(s) the activation of a solid adsorbent?A. Polishing the surface of the solid adsorbent.B. Subdividing the solid adsorbent.C. Blowing superheated steam through the porous adsorbent.D. Adsorbent at very low pressure. |
| Answer» Correct Answer - B::CCorrect Answer - B::C | |
| 919. |
If a beam of light is passed through true solution, then it isA. visibleB. scatterC. not visibleD. None of the above |
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Answer» Correct Answer - C When a beam of light is passed through true solution, then the path of light is invisible due to fact that the size of particles in true solution is below 1 nm, so they cannot scatter the light that means cannot show Tyndall effect. |
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| 920. |
During dialysisA. only solvent molecules can diffuseB. solvent molecules, ions and colloidal particles can diffuseC. all kinds of particles can diffuse through the semipermeable membraneD. solvent molecules and ions can diffuse |
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Answer» Correct Answer - D The principle of dialysis is based upon the fact that colloidal particles cannot pass through a parchment or cellophane membrane while the ions of the electrolyte can pass through it. |
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| 921. |
The ability of ion to bring about coagulation of a given collidal solution depends uponA. its chargeB. the sign of the charge aloneC. the magnitude of its chargeD. both magnitude and sign of its charge |
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Answer» Correct Answer - D According to Hardy-Schulze law. coagulation `prop` charge of ion. So, coagulation is affected by both magnitude of charge and nature of charge. For coagulation of a positive sol, negative ions are required and for coagulation of negative sol, positive ions are required. Greater the magnitude of charge, quicker will be the coagulation. The ions having opposite charge to sol particle causes coagulation. Coagulating power of an electrolyte is directly proportional to the fourth power of the valence of the ions causing the coagulation. |
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| 922. |
The ability of ion to bring about coagulation of a given collidal solution depends uponA. Its sizeB. The magnitude of its charge onlyC. The sign of its chargeD. Both the magnitude and the sign of its charge |
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Answer» Correct Answer - D The ability of an ion to bring about coagulation of a given colloids depends upon both the magnitudes and sign of its charges. |
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| 923. |
Which of the following statements are correct about solid catalyst?A. Catalyst is requried in equal amount as the reactants present in the reaction.B. Catalytic activity of a solid catalyst does not depend upon the extent of chemisorption.C. Desorption is not important for a solid to act as good catalystD. Same reactant may give different products by using different catalysts. |
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Answer» Correct Answer - D A catalyst is specific in nature. Same reactants can give different products with different catalysts. |
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| 924. |
Which can adsorbe large volume of hydrogen gas ?A. Finely divided platinumB. Colloidal solution of palladiumC. Small pieces of palladiumD. A single metal surface of platinum |
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Answer» Correct Answer - B In colloidal solution the particles are suspended and are more dispered than powdered form hence adsorption is maximum. |
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| 925. |
What is meant by critical micellization concentration? |
| Answer» The micelle may be defined as the aggregated particles formed by associated collods in solution. The formation of micelles takes place above certain concentration called critical micellization concentration `(CMC)` . Every micelle system has a specific value of `CMC` . The micelle may be defined as the aggregated particles formed by associated collods in solution. The formation of micelles takes place above certain concentration called critical micellization concentration `(CMC)` . Every micelle system has a specific value of `CMC` . | |
| 926. |
What type of substances from hyphobic sols? |
| Answer» Substances such as metals, their sulphides, etc., which do not mix directly with the dispersion medium from a lyophobic sol. Substances such as metals, their sulphides, etc., which do not mix directly with the dispersion medium from a lyophobic sol. | |
| 927. |
Difine emulsification? |
| Answer» The process of making an emulsion from oil is termed as emulsification. The process of making an emulsion from oil is termed as emulsification. | |
| 928. |
Amongst `Na^(+), Ba^(2+), Al^(3+)`, which coagulates negative sol readily and why ? |
| Answer» The order of coagulating ability of given ions with negative sols is `Al^(+3) gt Ba^(+2) gt Na^(+)` | |
| 929. |
An emulsion can be diluted with `H_(2)O` (dispersion medium) , then it isA. O/W typeB. W/O typeC. Both (a) and (b)D. None of these |
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Answer» Correct Answer - A An emulsion can be dilluted with `H_(2)O` then it is O/W type . |
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| 930. |
Tyndall effect will be observed in :A. solutionB. precipitateC. solD. vapour |
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Answer» Correct Answer - C |
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| 931. |
Which one of the following is an example of a hydrophobic colloidal sol?A. A starch solution in waterB. A gold solC. A jellyD. A gelatin |
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Answer» Correct Answer - B Metal sols are lyophobic sols |
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| 932. |
Which of the followimg statements is correct?A. If the mutual affinity between the dispersed phase and dispersion medium is great, the colloidal system is solid to be lyophilic.B. If the mutual affinity between the dispersed phase and dispersion medium is small, the colloidal system is solid to be lyophilic.C. In a sol if water is the dispersion medium, the system is termed hydrophobicD. All of these |
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Answer» Correct Answer - D Depending upon the nature of interaction between the dispersad phase and the disperion colloidal sols are divided into two categories nemely lyophilic solvent attracting and lyophodic solvent repelling if water is hydrophobic The word lyophilic means liquid-loving colloidal sols directly formd by substances like gum gelatin starch rubber etc. no mixing with a suitable liquid the dispession medium are calliod lyophilic sols The word lyophodic means liquid hating substances like metaks their sulphides etc when simply mixed with the dispersion medium do not form the colloidal sol their colloidal sols can be prepared only by special methods such sols are called lyophobic sols |
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| 933. |
Which of the following statements is correct in the context of micelles?A. Micelles are ture solutionsB. Micelles are formed below critical micelle concentration.C. Micelles are formed above critical micelle concentration.D. Micelles are not associated colloids |
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Answer» Correct Answer - C Associated colloids form micelles above a particular concentration called critical micelle concentration `(CMC)` . On dilution, these colloids revert back to individual ions. Surface active agenets such as soaps and synthetic detergents belong to this class. For soaps, the `CMC` is `~10^(-4)` to `10^(-3)molL^(-1)` . Micelles may constain as `100` molecules or more. Macromolcular colloids, which are quite stable, resemble true solutions in many respects. |
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| 934. |
Micelles are formed above a particular temperature calledA. Kraft temperatureB. Boyle temperatureC. absolute temperatureD. critical temperature |
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Answer» Correct Answer - A The Formation of micelles takes place only above a particular temperature called Kraft temperature `(T_(k))` . |
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| 935. |
Muddy water can be purified through coagulation usingA. Common saltB. AlumC. SandD. Lime |
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Answer» Correct Answer - B Alum is added to muddy water so as to destroy the bacteria as wellas to coagualted the suspended impurities. |
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| 936. |
Name the four positively charged sols. |
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Answer» The following are the positively charged sols. `to ` Hydroated metallic oxide sols Eg : `Al_(2)O_(3) .xH_(2)O, CrO_(3).xH_(2)O` etc. `to` Basic dye stuffs Eg : Methylene blue sol. `to` Hemoglobin (blood). `to` Oxides Eg: `TiO_(2)` sol. |
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| 937. |
Micelles are formed above a particular temperature calledA. Critical temperatureB. Boyle temperatureC. Inversion temperatureD. Karft temperature |
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Answer» Correct Answer - D The temperature above which a surfactant forms micelle is called Kraft temperature or Kraft point. |
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| 938. |
What is the effect of temperature and pressure on the yields of products? a. `N_(2)(s)+3H_(2)(g) hArr 2NH_(3)+x cal` b. `N_(2)(g)+O_(2)(g) hArr 2NO(g)-y cal` c. `2SO_(2)(g)+O_(2)(g) hArr 2SO_(3)(g)+46.9 kcal` d. `PCl_(5)(g) hArr PCl_(3)(g)+Cl_(2)(g)-15.0 kcal`A. (ii),(iii)B. (ii),(iii),(iv)C. (i),(ii)(iii)D. (iv) |
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Answer» Correct Answer - A Heterogenous catlysis involved both in (ii) and (iii) because metal catalysts are used. |
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| 939. |
A colloidal solution of ferric oxide is prepared by two different methods as shown below. a. What is the charge on colloindal particles in the two test tubes `(A)` and `(B)`? b. Give reasons for the origin of charge. |
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Answer» Colloidal particles of test tube (A) are positively charged where as colloidal particles of test tube (B) are negatively charged. In test tube (A). `Fe^(3+)` is adsorbed on the precipitate `Fe_(2)O_(3).xH_(2)O` [or `Fe_(2)O_(3).xH_(2)O//Fe^(3+)` is formed]. In test tube (B). `overset(ɵ)(OH)` ions is adsorbed on the precipitate `Fe_(2)O_(3).xH_(2)O` [or `Fe_(2)O_(3).xH_(2)O//overset(ɵ)(OH)` is formed].Colloidal particles of test tube (A) are positively charged where as colloidal particles of test tube (B) are negatively charged. In test tube (A). `Fe^(3+)` is adsorbed on the precipitate `Fe_(2)O_(3).xH_(2)O` [or `Fe_(2)O_(3).xH_(2)O//Fe^(3+)` is formed]. In test tube (B). `overset(ɵ)(OH)` ions is adsorbed on the precipitate `Fe_(2)O_(3).xH_(2)O` [or `Fe_(2)O_(3).xH_(2)O//overset(ɵ)(OH)` is formed]. |
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| 940. |
Explain the following observation: a. A beam of light passing through a colloidal solution has a visible path. Passing an electric currenet through a colloidal solution removes colloidal particles from it. c. Ferric hydroxide sol coagulates on addition of potassium sulphate. |
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Answer» This is due to scattering of light by the colloidal particles (called Tyndall effect). b. This due to charge on the colloidal particles so that they migrate towards the oppositely charged electrode. c. Ferric hydroxide is a positively charged sol and is coagulated by `SO_(4)^(2-)` ions produced by `K_(2)SO_(4)` This is due to scattering of light by the colloidal particles (called Tyndall effect). b. This due to charge on the colloidal particles so that they migrate towards the oppositely charged electrode. c. Ferric hydroxide is a positively charged sol and is coagulated by `SO_(4)^(2-)` ions produced by `K_(2)SO_(4)` |
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| 941. |
A colloidal system involves :-A. A state of dissolutionB. A state of dipersionC. A state of supensionD. None |
| Answer» Correct Answer - B | |
| 942. |
Which is the correct statement in case of milk?A. Milk is an emulsion of fat in waterB. Milk in an emulsion of protein in waterC. Milk is stabilized by proteinD. Milk is unstabilized |
| Answer» Correct Answer - A | |
| 943. |
Discuss the use of colloids in Tanning. |
| Answer» Timing: Animal skins are colloidal In nature. When a skin, which has positively charged particles, is soaked in tannin, which contains negatively charged colloidal particles, mutual . coagulation takes place. This results In the hardening of skln weather). Thls process is termed as tanning. Chromium salts are also used In place of tannin. | |
| 944. |
Discuss the use of colloids in Medicines. |
| Answer» Medicines : Most of the medicines are colloldal in nature. For example argyrol is a silver sol used as an eye lotion. Colloidal antimony is used in curing kalaazar. Colloidal gold is used as intrainuscular injection. Milk of magnesia, an emulsion, is used for stomach disorders. c olloidal medicines are more effective because they have large surface area and are therefore easily assimilated. | |
| 945. |
Which of the following statement regarding micelle is incorrect?A. It is formed at a certain minimum concentration known as CMC.B. It contains a charged terminal, either positive or negative.C. On dilution, a micelle turns into normal solution.D. It is formed below Kraft temperature. |
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Answer» Correct Answer - D |
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| 946. |
Milk is an example of :A. true solutionB. gelC. suspensionD. emulsion |
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Answer» Correct Answer - D |
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| 947. |
Discuss the use of colloids in Purification of drinking water . |
| Answer» Purification of drinking water: The water obtained from natural sources often contains suspended impurities. Alum is added to such water to coagulate the suspended impurities and make water fit for drinking purposes. | |
| 948. |
Which is the correct statements in case of milk `:`A. Milk is an emulsion of fat in waterB. Milk is an emulsion of protein in waterC. Milk is stabilized by proteinD. Milk is stabilized by fat |
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Answer» Correct Answer - 1 Milk is an emulsion of fat in water. |
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| 949. |
Which is the correct statement in case of milk?A. Milk is an emulsion of fat in waterB. Milk is an emulsion of protein in waterC. Milk is stabilized by proteinD. Milk is stablilized by fat |
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Answer» Correct Answer - A |
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| 950. |
By which method precipitate is converted into colloids? |
| Answer» Correct Answer - Peptisation | |