File Name: surface tension viva questions and answers .zip
The principle is to measure the weight of drops of a fluid of interest falling from a capillary glass tube , and thereby calculate the surface tension of the fluid. We can determine the weight of the falling drops by counting them. From it we can determine the surface tension.
Chapter List. The property of liquid by virtue of which it tries to occupy minimum surface area within the given volume is called surface tension. When a certain force is applied on a liquid through, then the work done by this force will be stored in the form of energy.
Experiment No. The property of water which restricts or check the lather formation with soap is called hardness. Ca HCO3 2 and Mg HCO3 2 it is caused by the presence of Carbonates and bicarbonates mainly bicarbonate of calcium and magnesium and is removed by boiling of water and sludge formation takes place. For its removal water has to be treated chemically. Permanent hardness of water can be removed by several methods. The hardness of any given water sample may be determined by the following methods.
The best method for determining hardness of water is E. Write its structure. The structure and name of E. Give structure. It is used as disodium salt of E. Part per million ppm -: It is number of parts of CaCO 3 equivalent hardness present in one million parts of water.
The indicator used in this titration E. Usually it is a solution containing 1 gm. The pH of buffer solution is Sodium salt of EDTA is often used as a complexing agent in titrations. A buffer solution gives acidic as well as basic ions in solution which destroy the excess of any acid or base added keeping the pH constant. It serves as a hexadentate legend and acts as a chelating agent. The knowledge of alkalinity of water is necessary due to following : For controlling corrosion of boiler.
In conditioning boiler feed water as highly alkaline water which may lead to caustic embrittlement and deposition of precipitates and sludges in boiler tubes and pipes. In calculating amounts of lime and soda required for water softening. In neutralizing acidic solutions produced by hydrolysis of salts. The amount of coagulant like aluminium sulphate and ferrous sulphate to be added depends upon the amount of alkalinity of water. To control of alkalinity of water being used for irrigation purpose.
The alkalinity of water can be considered to be mainly due to 1. Hydroxides 2. Carbonates 3. Bicarbonates With respect to the constituents causing alkalinity in natural water the following situation may arise. Bicarbonates 4. Hydroxides and Carbonates 5. Carbonates and Bicarbonates The possibility of hydroxides and bicarbonates existing together is rules out owing to the fact that they combine with each other forming the respective carbonates. The type and extent of alkalinity present in a water sample may be conveniently determined by nitrating as aliquot of the sample with a standard acid to phenolphthalein endpoint [P] and then continuing the titration to methyl orange end point [M] the reaction taking place may be represented by the following equation.
The volume of acid run down up to phenolphthalein end-point [P] corresponds to the completion to equation i and ii given above while the volume of acid run down after [P] corresponds to the completion of equation iii. The total amount of acid used from the beginning of the experiment i. H Red III. A sufficient excess of the weak acid has to be added to get the end point. Phenolphthalein is an acid base indicator which work in a pH range of 8. It is colourless in acidic solution and pink in alkaline solution.
When a weak base like NH4OH is titrated with a strong acid, the OH - ions furnished by the weak base at the end point of titration are too few to shift the equilibrium sufficiently towards the right to raise the pH value to 8. A sufficient excess of weak base has to be added to get the pink colour.
Different fertilizers are employed for C different types of the vegetation and so it is significant that alkalinity is due to which ion and the amount of that ion in irrigation water. An important characteristic of water is its alkalinity. Which is a measure of the ability of water to neutralize the acids. The alkalinity of water is normally due to the presence of bicarbonates, carbonates and the hydroxides of sodium, potassium, calcium and magnesium.
Some of the salts, not all, which case alkalinity, also cause OH hardness. However presence of other bases such as borates, silicates, phosphates can also contribute to the total alkalinity, through to a small extent. I colourless II OH-. Phenolphthalein pH 8. What type of alkalinity is present? Absent of CO and OH-. Only HCO3- may be present.
In a chemical reaction, C if any substance is oxidized the other is reduced. In other words oxidation and reduction is simultaneously. Oxidation is define as the process of loss of one or more electron and reduction is the gain of one or more electron by atom of ions.
Give one example of each. Internal indicator -: An indicator which is added to the reaction mixture to indicate the end point of titration.
Example -: Phenolphthalein in acid base titrations. External indicator -: An indicator which is not added to the reaction mixture. But it is used externally to indicate end point of titration. Self indicator-: When one of the reactants it acts as indicator and no external substance is required to indicate the end point of titration. Example: - KMnO4 acts as self indicator in its titrations. In a hydrated crystal definite amount of water molecules are combined with each molecule. This is called water of crystallization.
H2SO4 is always added while preparing the standard solution of Mohrs salt? To prevent the hydrolysis of Mohrs salt dil.
H 2SO4 is added. In order to prevent this H 3PO4 is added which forms a complex with ferric ions [Fe PO4 2]3- and prevent the oxidation of indicator before the end point. The reaction between oxalic acid and KMnO4 is very slow. Thus the increase the rate of reaction the solution is heated. Explain Ans. It cannot be obtained in perfectly pure state as it always contains traces of manganese dioxide.
KMnO4 may react with organic matter present in water in which is dissolved. KMnO4 solution slowly decomposes when exposed to bright sun light, reducing gases etc. Therefore, it is stored in dark coloured bottles. KMnO4 solution can be standardized using a suitable primary standard such as oxalic acid or Mohrs salt, which can be directly weighed.
This is due to higher oxidizing power of permanganate ion in acidic medium then in neutral or alkaline medium. Moreover the formation of brown coloured MnO 2 in alkaline medium interferes with the detection of the end point. The reaction between oxalic acid and KMnO 4 is very slow. Three type of indicators are there: 1. External indicators-: These indicators are not added in the titration flask but are kept outside on a porcelain plate. The solution in the titration flask is withdrawn with a dropper after each addition of the titrant from the burette and placed on indicator to see the colour change.
Example of external indicator K3[Fe CN 6] 2. Internal indicators-: There are added to the solution taken in the titration flask. Example includes phenolphthalein, methyl orange and starch solution. Self indicators -: When one of the reactant acts as an indicator. The reaction is slow in the beginning but quite fast afterwards due to the formation of MnSO4 as one of the products. The reaction is accelerated because MnSO 4 acts as a catalyst.
This is due to the formation of MnO2. The organic matter of filter paper is oxidized by KMnO4. At neutral pH, some combined chlorine residuals do not liberate I2 by reaction with KI. The titrations involving the use of iodine are termed as iodine titrations. Iodine is a mild oxidizing agent and is used in volumetric estimations.
Iodine titrations are of two types: a Iodimetry-: All such titrations which involve the direct titration of iodine with a reducing agent are grouped under iodimetry. Iodimetry is employed to determine the strength of reducing agents such as sodium thiosulphate, sulphite, arsenite stannous and ferrous ions in neutral or moderately acidic solutions.
The liberated iodine is then titrated with a reducing agent. Iodometry is used to estimate the strength of oxidizing agents. The indicator is used in these type of titrations is starch solution which is used as an internal indicator.
Starch forms a dark blue complex with triodate ions. The blue colour disappears when there is no more of free iodine.
Aim To determine the surface tension of water by capillary rise method. Apparatus Three capillary tubes of different radii and a tipped pointer clamped in a metallic plate with a handle, travelling microscope, clamp and stand, a fine motion adjustable height stand, a flat bottom open dish, clean water in a beaker, thermometer. Place the adjustable height stand on the table and make its base horizontal by level-ling screws. Take dirt and grease free water in an open dish with flat bottom and put it on the top of the stand. Take three capillary tubes of different radii ranging from 0. Clean and dry them, clamp the capillary tubes in a metallic plate in order of increasing radius. Also clamp a pointer after third capillary tube.
Fluid is a substance that a cannot be subjected to shear forces b always expands until it fills any container c has the same shear stress. Ans: d. Fluid is a substance which offers no resistance to change of a pressure b flow c shape d volume e temperature.
Агент Смит! - позвал Фонтейн. Из-за спины Беккера появилось лицо Смита. - Слушаю, сэр. - Мне кажется, мистер Беккер опаздывает на свидание. Проследите, чтобы он вылетел домой немедленно.
Стратмору, разумеется, это было хорошо известно, но даже когда Сьюзан порывалась уйти через главный выход, он не обмолвился об этом ни единым словом. Он не мог пока ее отпустить - время еще не пришло. И размышлял о том, что должен ей сказать, чтобы убедить остаться. Сьюзан кинулась мимо Стратмора к задней стене и принялась отчаянно нажимать на клавиши. - Пожалуйста, - взмолилась .
Если до этого Хейл не знал, что они идут, то теперь отлично это понял. Стратмор нажал несколько кнопок и, прочитав полученное сообщение, тихо застонал. Из Испании опять пришли плохие новости - не от Дэвида Беккера, а от других, которых он послал в Севилью. В трех тысячах миль от Вашингтона мини-автобус мобильного наблюдения мчался по пустым улицам Севильи. Он был позаимствован АНБ на военной базе Рота в обстановке чрезвычайной секретности.
Linear algebra and its applications by lay lay and mcdonald 5th edition pdf using functional grammar an explorers guide pdfAnatolio S. 13.06.2021 at 11:19
Surface Tension and Viscosity Experiment. The surface tension (capillary rise) Viva Questions and Answers. (i) Define surface tension. Ans: It is.Nimsi A. 16.06.2021 at 15:32
Ans: They are the same.Angelicgrace 16.06.2021 at 16:42
Experiment No.Raymond C. 17.06.2021 at 19:42
Surface Tension – Viva Voice Questions With Answer | Physics Class 1: Define surface tension? 2: What are units of surface tension in C.G.S. and S.I. 3: What are cohesion and adhesion force? 4: What are the factors affecting the surface tension? 5: What is the effect of temperature on the surface tension?