Solutions Questions and Answers

a 0 06 M b 0 09 M c 1 2 M d 0 80 M 92 Calculate the mass of anhydrous HCl in 10 mL of concentrated HCl density 1 2 g mL solution having 37 HCl by mass a 4 44 g b 4 44 mg c 4 44 x 10 3 mg 93 Calculate the molality of 1 I solution of 80 H SO GAN d 0 444 g

When CO g is passed over red hot coke it partially gets reduced to CO g Upon passing 0 5 litre of CO g over red hot coke the total volume of the gases increased to 700 mL The composition of the gaseous mixture at STP is AIEEE ONLINE 2012 1 CO2 3 CO2 200 mL CO 500 mL 0 0 mL CO 700 mL 2 CO 350 mL CO 350 mL 4 CO 300 mL CO 400 mL

5 Vapour pressure of chloroform and dichloromethane at 298K are 200 mm Hg and 415mm Hg resp i Calculate the vapour pressure of solution prepared by mixing 25 5g of CHCI3 and 40g of CH2C12 at 290K ii Calculate the mole fraction of each mponent

Which one of the following aqueous solutions when mixed with an equal volume 0 10 mol L 1 aqueous NH3 will produce a buffer solution A 0 050 mol L 1 NaOH B 0 10 mol L 1 CH3COOH C 0 10 mol L 1 HCI D 0 20 mol L 1 HCI E 0 20 mol L 1 NH4Cl

1 NaOH 58 The strength in volumes STP 22 4 litre 1 10 volume 100 2 KOH 3 RbOH 4 LiOH of a solution containing 30 36 g L of H O is Given volume of 1 mole of gas 2 20 volume 3 5 volume 4 None of these

hich is correct about Henry s law 1 The gas in contact with the liquid should behave as an ideal gas 2 There should not be any chemical interaction between the gas and liquid 3 The pressure applied should be high 4 All of these 4 mole ratio of pentar

Raoult s law is not applicable to which solution 1 Very dilute solution 2 Ideal solution 3 Solution with volatile solute 4 Solution with non volatile solute Th onour pressure of solution is than th

53 If a 5 25 mass vol solution of a non electrolyte is isotonic with 1 50 mass vol solution of urea molar mass 60 is the same solvent then the molar mass of non electrolyte is 1 a 210 0 g mol c 115 0 g mol b 90 0 g mol 1 d 105 g mol 1 of pure liquids benzen

a Give reasons for the following 3 i Mn is a good oxidising agent ii EM M values are not regular for first row transition metals 3d serie iii Although F is more electronegative than O the highest Mn fluori is MnF4 whereas the highest oxide is Mn O b Complete the following equations i 2CrO2 2H ii KMnO heat

10 3 The boiling point of a solution containing 3 x kg non volatile substance present in 50 10 3 kg water is 373 5 K the molar mass of the substance Kb 0 52 K kg mol a 36 2 g mol c 60 6 g mol b 58 49 g mol 1 d 52 4 g mol

5 mL acetone is mixed with 100 mL of water The vapour pressure of water above the solution will be a Equal to the vapour pressure of pure water b Equal to the vapour pressure of the solution c less than the vapour pressure of the pure water d more than the vapour pressure of

2 moles of octane in beaker 1 and 3 moles of nonane in beaker 2 are enclosed in a chamber A in beaker 3 2 moles of octane and 3 moles of nonane are mixed and this beaker is placed in chamber B At equilibrium at the same temperature vapour pressure in chamber A will be a greater than that in chamber B b less than that in chamber B c Same as that in chamber B d Greater or less than in chamber B depending upon temperature

A room 4 x 4 m square by 3 m high has one side wall maintained at 260 C the floor is maintained at 90 C The other four surfaces are perfectly insulated Assume that all surfaces are black Calculate the net heat transfer between the hot wall and the cool floor

7 0 635 x 10 kg of a substance of molar mass 190 10 kg mol was dissolved in 30 5 x 10 kg of a solvent If the depression in the freezing point is 0 62 C find the molal depression constant of the solvent 2 marks

To prepare a buffer of pH 8 26 amount of NH4 2 SO4 to be added to 500 mL of 0 01 M NH4OH solution is pKa NH4 9 26 A 0 05 mole C 0 10 mole B 0 025 mole D 0 005 mole

The system that forms maximum boiling azeotrope is a carbon disulphide acetone b benzene chloroform c acetone chloroform d n hexane n heptane

In a mixture of A and B components show negative deviation when 1 A B interaction is stronger than A A and B B interaction 2 A B interaction is weaker than A A and B B interaction 3 AV 0 AS 0 4 AV 0 AS 0

Estimate the molal solubility of oxygen in water at 25 C and a partial pressure of 21 kPa Henry s constant of oxygen at 25 C 7 92 X 104 k Pa kg mol Select one a b 5 56 X 104 mol kg 2 60 X 104 mol kg 2 65 X 104 mol kg d 2 9 X 104 mol kg 290 X 104 mol kg C D

Which of the following graphs represent the behavior of ideal binary liquid mixture a Plot of 1 PTotal against yA is linear b Plot of 1 PTotal against y is non linear c Plot of PTotal against yA is linear d Plot of PTotal against y is linear

Moles of K SO4 to be dissolved in 12 moles of H water to lower its vapour pressure by 10 mm at a temperature at which vapour pressure of pure water is 50 mmHg is A 3 mol C 1 mol B 2 mol D 0 5 mol

Suppose you need to prepare 117 3 mL of a 0 434 M aqueous solution of NaCl What mass in grams of NaCl do you need to use to make the solution Type answer

The equivalent conductance of monobasic acid at infinite dilution is 438 ohm cm eq If the resistivity of the solution containing 15g of acid Molecular weight 49 in 1L is 18 5 ohm cm What is the degree of dissociation of acid A 45 9 C 60 4 B 40 2 D 50 7

The V Ps of two pure liquids A B at t C are 75 and 21mm Hg resp The two when mixed form an ideal solution What is the mole ratio A B in which the two be mixed to get a solution whose V P at t C is 39mm Hg 1 2 3 2 5 3 3 2 1 4 1 2 at the same temperature when 1g of B is dissolved

Freezing point of 0 2 M KCN solution is 0 7 C On adding 0 1 mole of Hg CN to one litre of the 0 2 M KCN solution the freezing point of the solution becomes 0 53 C due to complete conversion of Hg CN into complex ion Hg CN 2 by the reaction Hg CN mCN Hg CN What is the value of m m 2

Problem 36 For 10 minutes each at 27 C from two identical holes nitrogen an an unknown gas are leaked into a common vessel of 3 litre capacity The resulting pressure is 4 18 bar and the mixture contains 0 4 mol of nitrogen What is the molar mass of the unknown gas 300

4 Trideuteroacetaldehyde solute is 90g non volatile non dissociative added to 17496g water to form a dilute ideal solution The vapour pressure of water has decreased from 300mm of Hg to 291mm of Hg The molecular weight of solute is 1 90 2 60 3 30 4 15

6pts Part D Density of Metal Unknown number 1 4 for your unknown metal Mass of solid Initial volume of water Final volume of water 2pts Volume of solid ml 2pts Density of solid g mL 2pts Identity of metal Choose 2 53 40 g 51 3 ml 57 4 ml

18 OH OH CH 3 4 Benzene and toulene form an ideal solution 3 mole benzene and 2 mole toulene are added V P of pure benzene and toulene are 300 200 mm of Hg respectively The V P of the solution in mm of Hg is 1 500 2 250 3 260 4 440

A solution has a 1 4 mole ratio of pentane to hexane The V Ps of the pure hydrocarbons at 30 C are 440 mm Hg for pentane 120 mm Hg for hexane The mole fraction of pentane in the vapour phase at 16 30 C is 1 0 2 2 0 478 3 0 549 4 0 786

2 When 17 4 g of a solid is dissolved into 25 0 mL of water the volume of the solution becomes 28 2 mL What is the percent W V concentration of the solutio a 88 7 c 69 6 d 38 3 e 61 7 b 30 4

b Calculate the volume of water which could be added to 20 ml of 0 65 m HCl to dilute the solution to 0 2 m 1 a What happens when red blood cells are placed in 0 1 NaCl solution b Calculate the osmotic pressure of 0 25 M solution of urea at 370C R 0 083 L bar mol k

134 The electrical conductivity of a solution serves as a means of determining the end point in a chemical reaction involved in the titration of acids bases or precipitation Which of the following conductometric titrations represent the curve of HCI vs NH4OH x axis Volume of alkali added y axis Conductivity 1 3 End point ED End point 2 4 Too End point End point 001 831

5 Total vapour pressure of mixture of 1 mol volatile component B PA 100 mmHg and 3 mol of volatile component B PB 60 mmHg is 75 mm For such case H H le CH H H 1 There is positive deviation from Raoult s law 2 Boiling point has been lowered 3 Force of attraction between A and B is smaller than that between A and A or between B and

ILLUSTRATION 8 1 If the density of methanol is 0 793 g mL what is its volume needed for making 2 5 L of its 0 25 M solution Solution We know M WBX 1000 MB XV Given M 0 25 mB 32 V 2500 mL 0 25 We know WB X1000 32 2500 Mass Volume x Density 20 Volume 0 793 Volume 25 22 mL or we 20 g ILLUSTRATION 8 2 Molarity of H SO4 is 0 8 and its density is 1 06 g mL What will be its concentration in terms of molality and mole fraction Solution Mass of H SO4 dissolved in 1 liter wg Mass of 1 liter solution 1000 x 1 06 1060 g Mass of solvent wA 1060 78 4 981 6 g WB X1000 78 4 1000 We know m 0 815 MB X WA 98 981 6 H Mole fraction of solute XB 0 8 nB NA NB 981 6 18 0 8 0 8 54 53 0 8 i 0 8 98 78 4 g 0 014

13 An aqueous solution of a compound AB freezes at 0 48 C At this temperature AB behaves as a Non electrolyte The same solution boils at 100 26 C at a P of 1 atm for water k kb 0 37 we can conclude that compound AB at the boiling point of solution a Behaves as a non electrolyte b Ionises to the extent of 50 c Behaves as a strong electrolyte d Dissociates in solution

c 52 m S 35 Which of the following expressions correctly represents the equivalent conductance at infinite dilution of Al2 SO4 3 Given that A 8 are the mol A13 3A so A 3 A A1 so equivalent conductances at infinite dilution of the respective ions a 2A A13 and A so b 2A 8 2 6 4 A A13 A Al3 So 1 A so

3 A living cell contains a solution which is isotonic with 0 2 M glucose solution What osmotic pressure develops when the cell is placed in 0 05 M BaCl solution at 300 K a 1 23 atm b 6 15 atm c 3 69 atm d None of these

7 The volume of water K 18 6 k molal in 100 g solvent required to dissolve 3 g of urea to produce a depression of 0 186 C in freezing point is a 1 L b 200 ml c 500 ml d 300 ml

38 V ml of an aqueous urea solution having osmotic pressure equal to 2 4 atm is mixed with V ml of another aqueous urea solution having osmotic pressure equal to 4 6 atm at if resulting same temperature What will be value of V solution after mixing has osmotic pressure equal to 2 95 atm a 1 c 2 In ak V b 1 5 d 3

Which of the following is correct for the reaction 3X X3 a represents degree of association Question Type Single Correct Type 1 2 3 4 3 2 1 i 2 3 1 i a 2 3 1 1 a 3 1 i

6 If all the four compounds were sold at the same price which would be cheapest for preparing an antifreeze solution for a car radiator a CH OH c C H OH b C H OH d C H OH

15 What volume of 0 1 Noxalic acid solution can be reduced by 250 g of an 8 percent by weight KMnO solution a 6 3 litre b 12 6 litre c 25 2 litre d 0 63 litre

A liquid Avapour 30 Which of the following azeotropes is not correctly matched a HNO 68 H O 32 Maximum boiling azeotrope B P 393 5 K b H O 43 HI 56 7 Minimum boiling azeotrope B P 290 K c C H OH 95 5 H O 4 5 Minimum boiling azeotrope B P 351 15 K d Chloroform 93 2 C H OH 6 8 Minimum boiling azeotrope B P 332 3 K

On increasing dilution of electrolytic solution A B C D Equivalent conductance decreases Molar conductance increases Specific conductance increases All of the above

C L 53 Dissolution of 1 5 g of a non volatile solute molecula weight 60 in 250 g of a solvent reduces its freezin point by 0 01 C Find the molal depression constant c the solvent a 0 01 c 0 0001 b 0 001 d 0 1

66 The Van t Hoff factor of 0 005 M aqueous solution of KCI is 1 95 The degree of ionisation of KCl is a 0 95 b 0 97 d 0 96 c 0 94 67 02 molal ag HA acid ionises to the extent of 20 V

The freezing point of a 4 w v aqueous solution of A is equal to the freezing point of 10 w v aqueous solution of B The molecular weight of A is 60 find out the molecular weight of B Assume both A and B are non electrolyte and molarity molality 1 150 3 45 2 90 4 180

a 0 85 C c 0 C b 3 53 C d 0 35 C 75 Maximum lowering of vapour pressure is observed in the case of a 0 1 M glucose c 0 1 M MgSO b 0 1 M BaCl d 0 1 M NaCl

27 Cyclohexane and Ethanol at a particular temperature have vapour pressures of 280 mm and 168 mm respectively If these two solutions having the mole fraction of cyclohexane as 0 32 are mixed the total vapour pressure is found to be 376 mm at the same temperature Should the mixture warm up or cool down after mixing Justify

21 Relative lowering in vapour pressure containing 1 mole K SO4 in 54g H O is K SO4 is 100 ionised 1 55 3 4 2 55 4 1 1 2