Answers posted by yamini.v

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During an adiabatic process , the pressure of a gas is formed to be proportional to the cube of its absolute temperature the value of r for the gas is

answered Mar 21, 2014

$P \propto T^3$$\implies P= KT^3$For adiabatic process $\begin{align*}\frac{T^x}{P^{x-1}} = C \end{a...

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A diamotic gas is heated at constant pressure such that it performs 4 J of work . Find the heat supplied to the gas

answered Mar 21, 2014

Answer : $\;14\;J$Explanation :Work done at constant pressure $=P \bigtriangleup V=P\;(V_{2}-V_{1}...

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P - T graph of an ideal gas is shown . Density of the gas at A is ' d ' and then density of the gas at B is

answered Mar 21, 2014

Answer : $\;\large\frac{3d}{2}$Explanation :$PV=nRT \quad $ n=no.of moles = mass / molar massTher...

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In a thermodynamic process 400 J of heat is given to a gas and 100 J of work is also done on set . Calculate the change in internal energy of the gas .

answered Mar 21, 2014

Answer : $\;500\;J$Explanation :$dQ=du+dw \quad $ By sign convention$dQ=+400\;J quad$ Heat absorbe...

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The ratio of molar heat capacities in path 1 and path 2

answered Mar 21, 2014

Answer : $\;< 1$Explanation :Path 1 : $\;dQ_{1}=du_{1}+dv$$\bigtriangleup Q_{1} =\bigtriangl...

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The internal energy of a system remains constant when it undergoes

answered Mar 21, 2014

Answer : A , B ,C are trueExplanation :in (A) , du=0 , since system corner back to initial state i...

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In P - V graph

answered Mar 21, 2014

Answer : $\;Temperature\;first\;decreases\;and\;then\;increases$Explanation :Temperature first de...

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The work done in cyclic process is

answered Mar 21, 2014

Answer : $\;\large\frac{\pi}{4}\;$$(P_{1}-P_{2})\;(V_{2}-V_{1})$Explanation :Work done = area unde...

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In the following diagram , the net amount of work done will be

answered Mar 21, 2014

Answer : negativeExplanation :1 . In a cyclic process clockwise cycle represents positive cycle ...

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In the following two isothermals shown at temperatures $\;T_{1}\;$ and $\;T_{2}\;$ . Which of the following relations is correct ?

answered Mar 21, 2014

Answer : $\;T_{2} > T_{1} $Explanation :PV = nRTFor a given V ,P will be greater for a higher ...

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A gas is taken along a cyclic path as shown ABCDA in P - V diagram in two ways the change in internal energy is

answered Mar 21, 2014

Answer : zero in two casesExplanation :It is a cyclic process , $\;\bigtriangleup u =0\;.$

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A system is taken from state A to state B through three different paths 1 , 2, 3 . The work done is minimum in

answered Mar 20, 2014

Answer : process 1Explanation :Work done = Area under the P - V curve . Which is maximum for pro...

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In an isochoric process $\;dQ : du\;$ =

answered Mar 20, 2014

Answer : $\;1 :1$Explanation :$dQ = du + dw$For isochoric process dw=0 Therefore , dQ=du

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The change in internal energy of a gas $\;du=$

answered Mar 20, 2014

Answer : $\;All\;the\;above$Explanation :$du=nC_{v}dT$$\large\frac{C_{p}}{C_{v}}=r$$C_{v}=\large...

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Some amount of heat given to a gas under isothermal conditions will result in

answered Mar 20, 2014

Answer : doing external workExplanation :$\bigtriangleup T=0\;$ . Hence b ,c and d are not possib...

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If $\;du_{1}\;,du_{2}\;,du_{3}\;$ are change in internal energy of gas in isobaric , isothermal and adiabatic processes , then for the same change in temperature

answered Mar 20, 2014

Answer : $\;du_{1} > du_{2} > du_{3}$Explanation :For all process for the same change in te...

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$PV=nRT\;$ is true for

answered Mar 20, 2014

Answer : both processExplanation :$Pv=nRT\;$ holds for all process . (for ideal gases)

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$dQ=du\;$ and $\;dw=0\;$ is

answered Mar 20, 2014

Answer : isochoric processExplanation :$dw=pdv$$\bigtriangleup w=\int pdv \; \quad since\; dv=0...

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Increase in internal energy of a gas corresponds to

answered Mar 20, 2014

Answer : Increase in kinetic energyExplanation :Inernal energy corresponds to the kinetic energy...

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Heat supplied to a gas at constant pressure is utilised to

answered Mar 20, 2014

Answer : both (a) and (b)Explanation : $dQ = du + pdv$$\bigtriangleup Q =\bigtriangleup u + p \bi...

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The amount of heat required to raise the temperature of a gas would be minimum when it is heated through

answered Mar 20, 2014

Answer : $\;1^{0}F$Explanation :The degree on the fahrenheit scale is smaller than that on kelvin...

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Which one of the following is not a surfactant ?

answered Mar 20, 2014

Answer : $\;CH_{3}-(CH_{2})_{14}-CH_{2}-NH_{2}$Explanation :A surfactant is briefly defined as a m...

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Which of the following phrases correctly explains syneresis ?

answered Mar 20, 2014

Answer : weeping of gelsExplanation :When gels are allowed to stand for a long time , they give ou...

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At which point of lyophilic colloids , they are expected to have minimum stability ?

answered Mar 20, 2014

Answer : isoelectric pointExplanation :The $\;H^{+}\;$ ions concentration at which the colloidal pa...

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Which of the following statements states the terms ' activity ' and ' selectivity ' respectively ?

answered Mar 20, 2014

Answer : ability of catalyst to increase the chemical reaction ; ability of catalyst to direct...

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Which of the following is the general formula of zeolites ?

answered Mar 20, 2014

Answer : $\;M_{\large\frac{x}{n}}\;[(AlO_{2})_{x}(SiO_{2})_{y}]mH_{2}O$Explanation :Zeolites are ...

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Among the following colloidal solo . Which one is given to a person having poisoning ?

answered Mar 20, 2014

Answer : $\;Fe(OH)_{3}$Explanation :Colloidal $\;Fe(OH)_{3}\;$ is given to a person having poisoi...

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Which of the following is another name for gold number ?

answered Mar 20, 2014

Answer : Congo rubin numberExplanation :Congo Rubin number was suggested by Ostwald and is express...

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Which of the following is a positively charged sol ?

answered Mar 20, 2014

Answer : $Metal\;hydroxides\;like\;Fe(OH)_{3}\;,Al(OH)_{3}\;,etc$Explanation :In a colloidal soluti...

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What are the type of solution in the two tumblers below respectively ?

answered Mar 19, 2014

Answer : true ; colloidalExplanation : When a strong beam of light is passed through a true soluti...

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Which set of colloidal solutions can be obtained by electrical dispersion / Bredig's are method ?

answered Mar 19, 2014

Answer : platinum , silver , goldExplanation :Paints & Varnishes can be obtained by mechanical...

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By which of the following methods . Gold sol is prepared ?

answered Mar 19, 2014

Answer : Reduction Explanation : The colloidal solutions of metals are obtained by redu...

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Which type of solution stated below shows the following properities ? $\;$(1) Homogeneous in nature $\;$ (2) It cant be separated by ultra filtration $\;$ (3) The appearance is transparent .

answered Mar 19, 2014

Answer : True soluotionExplanation :(1) Suspension & colloid solution are heterogeneous in natu...

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What will happen when $\;NH_{3}\;$ and $\;CO_{2}\;$ is placed on the surface of charcoal separately ?

answered Mar 19, 2014

Answer : $\;NH_{3}\;$ will be adsorbed more readily .Explanation :$NH_{3}\;$ has higher critical te...

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100 mL of a colloidal solution is completely precipitated by addition of 5 mL of 1 M NaCl solution . Calculate the coagulation value of NaCl .

answered Mar 19, 2014

Answer : 50Explanation :Coagulation value is the millimoles of an electrolyte that must be added to...

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What is obtained when a freshly precipitated $\;Fe(OH)_{3}\;$ is shaken with title amount of dilute solution of $\;Fecl_{3}\;$ ?

answered Mar 19, 2014

Answer : A reddish brown colloidal solution of $\;Fe(OH)_{3}$Explanation :When a freshly precipita...

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The coagulation of 100 ml of a colloidal solution of gold is completely prevented by the addition of 0.25 g of starch to it before adding 1 ml of 10% Nacl solution . Calculate the gold number of starch .

answered Mar 19, 2014

Answer : 25Explanation :Amount of starch added to 100 mL of gold sol required to prevent coagulat...

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Which of the following protective colloids has the maximum gold number ?

answered Mar 19, 2014

Answer : StarchExplanation :The gold number of the given options are in a range : - Gelatin (0.005...

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In a coagulation experiment $5 \;mL$ of $\;As_{2}S_{3}\;$ is mixed with disfilled water and $0.1\; M$ solution of an electorlyte $AB$ so that total volume is $10\; mL$ . It was found that all solutions containing more than $4.6\; mL$ of $AB$ coagulate with in $5$ minutes . What is the flocculation value of $AB$ for $\;As_{2}S_{3}\;$ sol ?

answered Mar 19, 2014

Answer : $46$Explanation :A minimum of 4.6 mL of AB is required to coagulate the sol . The moles o...

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Which of the following set is a colloid of solid -Gas i. e. Aerosol .

answered Mar 19, 2014

Answer : $\;Smoke\;,dust\;storm\;,haze$Explanation :Aerosol is a colloid of dispersion phase solid...

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Which of the following terms are also called as chemisorption ?

answered Mar 19, 2014

Answer : Activated adsorptionExplanation :Let us consider the example of adsorption of $\;H_{2}\;$...

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In the stoichiometry of natural faujasite -a zeolite with formula $\;Na_{x}[(Alo_{2})_{56}(Sio_{2})_{136}].2SOH_{2}O\;$ the value of x is

answered Mar 19, 2014

Answer : 56Explanation :Here , $\;SiO_{2}\;$ and $\;H_{2}O\;$ do net carry any charge . The char...

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Which of the following are correct pertaining to the adsorption of a gas can a solid surface ?

answered Mar 19, 2014

Answer : chemisorption is more exothermic than physisorption at high temperature.Explanation :He...

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At the lowest molar concentration at ambient conditions which among the following surfactant will form micelles in aqueous solution ?

answered Mar 19, 2014

Answer : $\;CH_{3}(CH_{2})_{15}N^{+}CH_{3}Br^{-}$Explanation :Greater is the size of the hydrophob...

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Adsorption is generally an

answered Mar 19, 2014

Answer : exothermic processExplanation :Adsorption is generally accompanied by decrease in rando...

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At isoelectric point the colloidal particles

answered Mar 19, 2014

Answer : coagulates & becomes electrically neutral .Explanation :At isoelectric point , colloid...

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Plot of $\;log\; \large\frac{x}{m}\;$ against $\;log\; P$ is a straight line inclined at an angle of $\;45^{0}\;$ . When the pressure is 0.5 atm and Freundlich parameter , $K$ is $10.6$ , the amount of the solute adsorbed per gram of adsorbed will be $\;(log\; 5 = 0.0990)\;$

answered Mar 19, 2014

Answer : $\;1\;g$Explanation :According to freundlich equation , $\;\large\frac{x}{m}=KP^{\large\f...

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Adsorption is accompanied by

answered Mar 19, 2014

Answer : decrease in free - energy of the system & enthalpy of the system bothExplanation :As...

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$10^{-4}\;g$ of gelatin is required to be added to $\;100\;cm^{3}$ of a standard gold sol to just prevent its coagulation by the addition of $\;1\;cm^{3}$ of $\;10\%\;$ NaCl solution to it . Hence , the gold number of gelatin is

answered Mar 19, 2014

Answer : $\;0.01$Explanation :By definition , gold number is the number of milligrams of dry prote...

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The colour of a colloidal solution depends upon

answered Mar 18, 2014

Answer : both a and cExplanation :Colour of a colloidal solution depends upon particle size and a...

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