Solutions Questions and Answers

A mixture of CO and CO when treated with 1205 give iodine vapour After removal of 12 residual gas was treated with excess of 0 1 N NaOH and the resulting solution required 30 ml of 1N HCI to reach end point using phenolphthalein and further 10 ml using methyl orange as indicator Total volume of NaOH in mL is X The value of is 10 40

Consider the following liquid vapour equilibrium 2016 Liquid Vapour Which of the following relations is correct denP AH b dT RT a c denG AH dT RT2 denP dr AH T d denP dT AH RT

3 Adding pressure to a closed half full bottle of water will cause a more of the liquid water to evaporate into the gaseous space b more of the water vapour in the gaseous space to condense into liquid wate C no change in the amount of water vs water vapour d the temperature of the water to decrease

If the mole fraction of solute in an aqueous solution is changed from the ratio of initial and final molality of solute in the solution is A 1 1 B 2 1 C 3 1 D 4 1 1 2 to 114 by adding water then

5 Which of the following is incorrect 1 Mass of the gas dissolved in liquid depends upon pressure of gas 2 Volume of the gas dissolved in liquid depends upon pressure applied 3 Value of K decreases on increasing temperature 4 Both 2 3

The vapour pressure of pure X are given by the following equation Sold X In P mm of Hg 10 3000 K T Liquid X In P mm of Hg 5 1800 K T Find out the freezing point of X 200 K 220 K 240 K 273 K

14 2 g Na SO4 was dissolved in X gm of H O The change in freezing point was found to be 3 82 C If Na2SO4 is 90 ionized the value of X Kf for water 1 86 C kg mol M Wt of Na SO4 142 g mol 1 1 363 g 2 0 1363 g 3 13 63 g 4 126 22

4x10 moles of a non volatile solute is added into 10 moles of solvent The solute polymerises into a soluble solid following first order kinetic with a rate constant equal to 0 693 min If after 2 min elevation in boiling point is observed to be 0 01 C then calculate which form the solute is getting polymerized into Given Molar mass of solvent 100 g mole K of solvent 0 5 K kg mol Instruction Mark 2 if polymer is dimer 3 if trimer and so on YOUR ANSWER D 2

Boiling point or freezing point of liquid solution would be affected by the dissolved solids in the liquid phase A soluble solid in solution has the effect of raising its boiling point and depressing its freezing point The addition of non volatile substances to a solvent decreases the vapor pressure and the added solute particles affect the formation of pure solvent crystals According to many researches the decrease in freezing point directly correlated to the concentration of solutes dissolved in the solvent This phenomenon is expressed as freezing point depression and it is useful for several applications such as freeze concentration of liquid food and to find the molar mass of an unknown solute in the solution Freeze concentration is a high quality liquid food concentration method where water is removed by forming ice crystals This is done by cooling the liquid food below the freezing point of the solution The freezing point depression is referred as a colligative property and it is proportional to the molar concentration of the solution m along with vapor pressure lowering boiling point elevation and osmotic pressure These are physical characteristics of solutions that depend only on the identity of the solvent and the concentration of the solute The characters are not depending on the solute s identity I 1 When a non volatile solid is added to pure water it will a boil above 100oC and freeze above 0oC b boil below 100oC and freeze above 0oC c boil above 100oC and freeze below 0oC d bail below 1000f and freeze below 000

2 56 An organic liquid A is immiscible with water When boiled together with water the boiling point is 90 C at which the partial vapour pressure of water is 526 mm Hg The atmospheric pressure is 736 mm Hg The weight ratio of the liquid and water collected is 2 5 1 The molecular weight of the liquid

3 Assume three samples of juices A B and C have glucose as the only sugar present in the The concentration of sample A B and C are 0 1M 5M and 0 2 M respectively Freezing point will be highest for the fruit juice a A b B c C d All have same freezing point

13 Which of the following statements is false 1 point O 1 Two different solutions of sucrose of same molality prepared in different solvents will have the same depression in freezing point ii The osmotic pressure of a solution is given by the equation CRT where C is the molarity of the solution iii Decreasing order of osmotic pressure for 0 01 M aqueous solutions of barium chloride potassium chloride acetic acid and sucrose is BaCl2 KCI CH3COOH sucrose iv According to Raoult s law the vapour pressure exerted by a volatile component of a solution is directly proportional to its mole fraction in the solution

Chemists classify material as heterogeneous or homogenebus and some homogeneous materials as pure substances Which of these are pure substances Gold and salt solutions Salt solutions and coal Sodium chloride and matures of sodium and potassium Gold and sodium chloride

1 Which of the following is correct for following graph B A C V P Composition 1 At point C composition in vapour phase will be same as in liquid phase 2 Boiling point of azeotropes will be more than A and B on 3 At point C both component having same boiling 10SM point 4 All of these

48 Equimolal solutions of NaCl and BaCl are prepared in water If the freezing point of BaCl solution is 3 C the freezing point of aqueous NaCl solution will be 1 3 C 2 2 C 3 1 C 4 4 C

5 The solution used to re acidify the basic solution was 6 M HCI The stockroom made 3 L of this solution so that all the lab sections had enough After looking up the molarity of concentrated HCI explain how this solution was made Please include calculations in your answer for full credit

If one litre of sea water which weighs 1100 g contains 6 6 x 10 g of dissolved oxygen then the concentration of oxygen in ppm is 2 5 ppm 6 ppm 6 8 ppm 12 ppm

9 200 mL of an aqueous solution of a protein contains Its 1 26g The osmotic pressure of this solution at 300 K is found to be 2 57 x 10 3 bar The molar mass of protein will be R 0 083 L bar mol K AIPMT Mains 2011 1 31011 g mol 1 3 51022 g mol 1 2 61038 g mol 1 4 122044 g mol 1

2 Which of the following solutions does not change its colo on passing ozone through it 1 Starch iodide solution est 2 Alcoholic solution of benzidine 3 Acidic solution of K Cr O 4 Acidified solution of FeSO4

200 mmHg and 400 mmHg are the vapour pressures of pure liquid components CHCl3 and CH Cl2 respectively which forms an ideal binary solution If 0 75 is the mole fraction of CHCI3 then the total vapour pressure of the solution will be 250 mmHg 200 mmHg 400 mmHg 350 mmHg

32 Two liquids A and B form a non ideal solution which obey the equation P P 3 P P x 2 P Pg x When equi molar mixture of A and B distilled find B the mole fraction of B when this mixture will have a single boiling point

Which of the following statements is incorrect 1 NaHCO3 on heating gives Na CO3 2 Pure sodium metal dissolves in liquid ammonia to give blue solution 3 NaOH reacts with glass to give sodium silicate 4 Aluminium reacts with excess NaOH to give Al OH 3

The total pressure exerted in ideal binary solution is given by P PAXA PBXB where P P are the respective vapour pressure of pure components and XA XB are their mole fraction in liquid phase And composition of the vapour phase is determined with the help of Dalton s law of partial pressure YA P If total pressure exerted in an ideal binary solution is given by P The correct option s is are If the value of YA 0 4 then the value of XA is 0 5 The more volatile liquid is liquid B The value of P is 60 mm of Hg If the value of YA 0 4 then the value of XR is 0 5 5400 60 30Y A mm of Hg

What is the significance of the re boiler in a distillation column Apply what you learn about the working principles of fractional distillation to explai

The following Absorbance vs concentration of nitrite graph is obtained for a set of data Absorbance 1 8 1 6 1 4 1 2 1 0 8 0 6 0 4 0 2 C 86 Absorbance Vs Concentration y 1 6628x 0 0373 R 0 9893 0 0 2 0 4 0 6 0 8 Concentration of nitrite mg L 1 Determine the concentration of unknown solution for which the absorbance is determined

21 A solution of urea mol mass 56g mole boils at 100 18 degree celcius at the atmospheric pressure If Kf and Kb for water are 1 86 and 0 512 K Kg mole respectively the above solution will freeze at 1 Point 6 54 degree celcius 0 654 degree celcius

Liquid C dissolves completely in water The vapour pressures at 20 C of an aqueou solution of C mol fraction 0 28 liquid C and water are 26 0 mmHg 43 5 mmHg ar 17 5 mmHg respectively Prove the aqueous solution C behaves as a non ide solution

The normal boiling point of pure water is 373 15K Calculate the boiling point in K of an aqueous solution containing 11 7 gm NaCl and 34 2 gm sugar C H O in 260 gm water For water K 0 52K Kg mol Atomic mass of Na 23 Cl 35 5 SKIPPED

27 Equivalent weight of MnO in acidic neutral and media are in ratio of c 5 1 13 d 3 15 a 3 5 15 b 5 3 1 28 NH OCIN H CI On balancing the above equation in basic solution integral coefficient which of the following whole nu will be the coefficient of N H a 1 b 2 c 3 d 4 9 In an experiment 50 mL of 0 1 M solution of a metall reacted exactly with 25 mL of 0 1 M solution of so sulphite In the reaction SO 2 is oxidised to SO original oxidation number of the metal in the salt w what would be the new oxidation number of the me a 0 b 1 c 2 d 4 20 mL of x M HCl neutralises completely 10 mL c M NaHCO solution and a further 5 mL of 0 2 M Na solution to methyl orange end point The value of x a 0 167 M b 0 133 M c 0 15 M d 02 M

0 0167 M solution of an oxidant for titrati number of electrons taken up by the oxidant in the reac of the above titration IIT JEE 19 20 A 2 0 g sample of a mixture containing sodium carbo sodium bicarbonate and sodium sulphate is gently he till the evolution of CO ceases The volume of CC 750 mm Hg pressure and at 298 K is measured t 123 9 mL A 1 5 g of the same sample requires 150 m M 10 HCl for complete neutralisation Calculate percentage composition of the components of the mix IIT JEE 15 1 One gram of commercial AgNO3 is dissolved in 50 of water It is treated with 50 mL of a KI solution silver iodide thus precipitated is filtered Excess C in the filtrate is titrated with M 10 KIO solution presence of 6 M HCl till all I ions are converted int

Illustration 7 130 H and I are mixed at 400 C in a 1 0 L container and when equilibrium is established the following concentrations are present HI 0 8 M H 0 08 M and 12 0 08 M If now an additional 0 4 mol of HI is added what are the new equilibrium concentrations when the new equilibrium H g L g 2HI g is re established

s 1 ar th in of M L requires 0 5 g of NaOH for complete neutralisation The number of replaceable hydrogen atoms and the molecular weight of A would be Mw of acid 96 a 2 94 d 4 92 b 1 95 c 3 93 55 A mixed solution of potassium hydroxide and sodium carbonate required 15 mL of an N 20 HCl solution when titrated with phenolphthalein as an indicator But the same amount of the solution when titrated with methyl orange as indicator required 25 mL of the same acid The amount of KOH present in the solution is a 0 014 g b 0 14 g c 0 028 g d 1 4 g 56 25 0 g of FeSO4 7H O was dissolved in water containing dilute H SO4 and the volume was made up to 1 0 L 25 0 mL of this solution required 20 mL of an N 10 KMnO solution for complete oxidation The percentage of FeSO4 7H O in the acid solution is 4 a 78 b 98 d 79 57 A 0 13 g of a specimen containing MnO is treated with iodide ions If iodine liberated requires 30 0 mL of 0 075 M solution of Na S O3 the percentage of MnO in the mineral is ho c 89 a 75 3 b 85 3 c 95 3 d None A Mod 58 The mass of K Cr O required to produce 5 0 L CO at 77 C and 0 82 atm pressure from excess of oxalic acid and volume of 0 1 N NaOH required to neutralise the CO evolved respectively are 24 31 a 7 g 2 86 L 101561 6 9 Boas b 5 g 1 86 L Jam d None c 4 g 0 86 L 59 A mixture of Na C O4 and KHC O4 H C O4 required equal o of 02 M KMnO and 0 2 M NaOH separately

If 8 g of a non electrolyte solute is dissolved in 114 g of n octane to reduce its vapour pressure to 80 the molar mass in g mol of the solute is Given that molar mass of n octane is 114 g mol NEET 2020 Phase 2 1 20 3 60 2 40 4 80

The osmotic pressure of urea solution at 10 C is 200 mm becomes 105 3 mm when it is diluted and temperature raised DO to 25 C The extent of dilution is 1 8 times 2 5 times 3 4 times 4 2 times

I mole of anhydrous X is added in 1 Kg water volume is finally I litre To this mixture small amount of Y is added such that it acts as Limiting reagent In each case Y reacts to give water soluble products Identify the correct option s List I X Y P KCN AgCN s S Q CuS Cone HNO R Hgly KI S CH COOH Ba OH s List II Effect of addition of Y on X water mixture 1 Freezing point decreases Osmotic pressure does not increases 2 3 Freezing point does not increases Vapour decreases A P 2 3 Q 1 3 R 1 4 S 3 4 pressure share 2 3 R 1 4S 3 4

5 Ethylene glycol is used as an antifreeze in a cold climate Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at 6 C will be K for water 1 86 K kg mol and molar mass of ethylene glycol 62 g mol 1 804 32 g 3 400 00 g 2 204 30 g 4 304 60 g AIEEE 2011

The K 25 C of sparingly soluble salt XY s is 3 56 x 10 5 mol L 3 and at 30 C the vapour pressure of its saturated solution in water is 31 78 mm of Hg Calculate the enthalpy change of the reaction XY s X aq 2Y aq Given Vapour pressure of pure water 31 82 mm of Hg

Two liquids A and B have vapour pressure of 0 600 bar and 0 2 bar respectively In an ideal solution of the two calculate the mole fraction of A at which the two liquids have equa partial pressures

6 If for a sucrose elevation in boiling point is 1 0 C then what will be the boiling point of NaCl solution for same molal concentration 3 3 0 C 1 1 0 C 2 2 0 C 7 Th 4 4 0 C 200

y 6 The degree of dissociation a of a weak electrolyte A B is related to van t Hoff factor i by the expression 1 3 i 1 x y 1 x y 1 i 1 2 4 i 1 x y 1 x y 1 i 1

6 Mole fraction of component A in vapour phase is X and mole fraction of component A in liquid mixture is X PA vapour pressure of pure A then the total vapour pressure of the liquid mixture is 2 1 PA 2 X PB X 3 PA XI X PB X2

0 5 m solution of acetic acid Mw 60 in benzene Mw 78 boils at 80 80 C The normal boiling point of benzene is 80 10 C and Ava H 30 775 kJ mol Calculate the percent of association of acetic acid in benzene

1 Two liquids X and Y form an ideal solution at 300 K vapor pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mm Hg At the same temperature if 1 mol of Y is further added to this solution vapor pressure of the solution increases by 100 mm Hg Vapor pressure in mm Hg of X and Y in their pure states will be respectively 1 200 and 300 2 300 and 400 3 400 and 600 4 500 and 600

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution the change in freezing point of water AT when 0 01 mole of sodium sulphate is dissolved in 1 kg of water is K 1 86 K kg mol

55 A solution of sucrose molar mass 342 has been prepared by dissolving 68 5 g of sucrose in 1000 g of water The freeqzing point of the solution obtained will be Kf for water 1 86 K kg mol 1 0 520 C 2 0 372 C 3 0 372 C 4 0 570 C

7 At 25 C the vapour pressure of pure methyl alcohol is 92 0 torr Mol fraction of CH OH in a solution in which vapour pressure of CH OH is 23 0 torr at 25 C is 1 0 25 2 0 75 3 0 50 4 0 66

9 The vapour pressure of pure liquid solvent A is 0 80 atm When a non volatile substance B is added to the solvent its vapour pressure drops to 0 60 atm the mole fraction of component B in the solution is 1 0 3 2 0 2 0 25 4 3 0

3 At 27 C the vapour pressure of an ideal solution containing 1 mole of A and 1 mole of B is 500 mm of Hg At the same temperature if 2 mol of B is added to this solution the vapour pressure of solution increases by 50 mm of Hg The vapour pressure of A and B in their pure states is respectively 1 600 mm 400 mm 3 300 mm 700 mm 2 400 mm 600 mm 4 200 mm 800 mm

ILLUS Acetic acid associates in benzene to form a dimer 1 65 g of acetic acid when dissolved in 100 g of benzene raised the boiling point by 0 36 C Calculate the Van t Hoff factor and degree of association of acetic acid K for benzene 2 57 C m

ILLUSTRATION 2 43 Liquids X and Y form an ideal solution The vapour pressure of X and Y at 100 C are 300 and 100 mm of Hg respectively Suppose that a solution composed of 1 mol of X and 1 mol of Y at 100 C is collected and condensed This condensate is then heated at 100 C and vapour is again condensed to form a liquid A What is the mole fraction of X in A