Solutions Questions and Answers

2 Two liquids A and B form an ideal solution The vapour pressure of pure A and pure B are 66 mm Hg and 88 mm Hg respectively Calculate the composition of vapour A in the solution which is equilibrium and whose molar volume is 36 1 0 43 0 30 2 0 70 4 0 50

A pH buffer is a solution that resists changes in pH when acids or bases are added to it typically a solution of a weak acid and its conjugate base What masses of dimethylamine and dimethylammonium chloride do you need to prepare 7 00 L of pH 12 00 buffer if the total concentration of the two components is 0 500 M Mass of dimethylamine 150 1 g Mass of dimethylammonium chloride

4 Which mixture of the solutions will lead to the formation of negatively charged colloidal AgI I sol a 50 mL of 0 1 M AgNO3 50 mL of 0 1 M KI b 50 mL of 1 M AgNO3 50 mL of 1 5 M KI c 50 mL of 1 M AgNO3 50 mL of 2 M KI AgNO 50 mL of 1 5 M KI

2 60 Sulphide ion in alkaline solution reacts with solid sulphur to form polysulphide ions having formula S2 S3 S etc if K 12 for S S S2 and K 132 for 2S S S3 K3 for S S S ort Telu all Irpingt 10 3

When some NaCl was dissolved in water the freezing point depression was numerically equal to twice the molal depression constant The relative lowering of vapour pressure of the soluon is Assume 100 NaCl aq dissociation A 0 117 C 0 0685 D 0 0089 B 0 034

At 40 oC the vapor pressure of n pentane n C5H12 is 873 mm and the vapor pressure ofn heptane n C7H16 is 92 mm Use Raoult s Law to calculate the vapor pressure at 40 oC of a 3 1 molar mixture of n pentane and n heptane Do the same for a mixture containing 50 g of each component

At 25 C vapour pressure of a volatile liquid A is 60 torr To 4 mol of A xmol of another volatile liquid B is added at 25 C The vapour pressure of the resulting solution was found to be 72 torr and mole fraction of A in the vapour phase was The value of x is 3

Derive the equation relating partial pressure of a component in a solution pa mole fraction of tha t same component in vapour phase of the mixture ya and total partial pressure pt state the law s used and how are they implemented

Sprinkling of salt helps in clearing the snow covered roads in hills The phenomenon involved in the process is a lowering in vapour pressure of snow b depression in freezing point of snow c melting of ice due to increase in temperature by putting salt d increase in freezing point of snow

100 mL of 0 2 M CaCl solution is isotonic with Assume completel dissociation of salts Select an answer A B C D 100 mL of 0 2 M C6H12O6 solution 200 mL of 0 3 M NaCl solution 100 mL of 0 3 M KCl solution 200 mL of 0 1 M Al2 SO4 3 solution

Insulin C H1005 n is dissolved in a suitable solvent and the osmotic pressure p of the solution of various concentration in kg m is measured at 20 C The slope of a plot of p against c is found to be 8 134 10 SI units The molecular weight of the insulin in kg mol is A 4 8 x 105 B 9 105 C 293 x 10 D 8 314 x 105

The boiling point of an azeotropic mixture of water and ethanol is less than that of water and ethanol The mixture shows a no deviation from Raoult s Law b positive deviation from Raoult s Law c negative deviation from Raoult s Law d that the solution is unsaturated

A beaker contains solution of substance A Precipitation of substance A takes place when small amount of substance A is added to the solution The solution is a Saturated c Unsaturated b d Supersaturated Concentrated

Na SO is added in water to make solution having density 1 2 g mL Correct statement for resulting solution is are a Nearly 0 96 mole of Na SO dissolved per kg of H O b Normality of Na ion is equals to normality of so2 ion c Molarity of solution is less than molality 1 a b 2 b only 3 c only

A solution is prepared by adding 55 00 g of fructose fruit sugar to 500 0 g of water at 30 C The partial pressure of water above the solution is atm The vapor pressure of pure water at 30 C is 4 19 x 10 2 atm The MW of fructose is 180 16 g mol

107 Which of the following statements is not correct for a nucleophile 1 Nucleophile is a Lewis acid 2 Ammonia is a nucleophile 3 Nucleophiles attack low electrons density sites 4 Nucleophiles are not electron seeking trig 1 2 3 112 IF

An aqueous solution has urea and glucose in miss ratio 3 1 If the mass ratio of water and glucose in the solution is 10 1 then the mole fraction of glucose in the solution is A 1 9 B 110 3 C D 110 110 100 110

3 Consider the following reaction of sodium thiosulphate with Cl Na S O3 aq 4Cl g 5H O 1 2NaHSO aq 8 HCl aq Choose the correct statement 1 0 3 mole of Na S O3 is required to react completely with 0 12 mole of Cl 2 0 24 mole of HCI will form from 0 12 mole of Cl on complete reaction 3 1 5 mole of water is required for the reaction of 0 12 mole of Cl 4 All are correct

By titrating vinegar with a standardized solution of sodium hydroxide the experimental acetic acid in the vinegar was determined and compared to the manufacturer s reported value DATA Volume of Vinegar Used mL Mass Vinegar Reported on Bottle Concentration of NaOH M Initial Burette Reading mL Final Burette Reading mL Volume of NaOH used mL Trial 1 5 00 mL Moles of NaOH Used mol Moles of Acetic Acid Reacted mol Mass of Acetic Acid Reacted g Molar Concentration of Acetic Acid M 5 0 25 2 01mL 11 01mL 9 ml CALCULATIONS Show one example calculation on the next page Trial 1 Trial 2 5 00 mL 5 0 25 11 01 mL 19 97 mL 8 96 mL Trial 2 Trial 3 Trial 3 5 00 mL 5 0 25 19 97mL 28 71 mL 8 71 mL Average

Solution of chloroform and acetone is an example of maximum boiling azeotrope A doctor advised a person suffering from high blood pressure to take less quantity of common salt State Raoult s law for the solution containing non volatile solute Give its mathematical expression also

In a binary solution of A PA 700 torr and B PB 500 torr if A and B were added in molar ratio of 2 3 then vapour pressure of B in the solution will be tions 280 torr 300 torr 580 torr 680 torr

an the 3 Electrop 15 Tyndall effect is not observed in 16 2 True solution 4 Colloidal solution 1 Suspension 3 Emulsions The process of removing dissolved impurition

What is the molality of the solution of a certain solute in a solvent if there is a freezing point depression of 0 184 and if the freezing point constant is 18 4 K kg mol 1 0 01 2 1 00 3 0 001 4 100

5 When cells of skeletal vacuoles of a frog were placed in a series of NaCl solutions of different concentrations at 25 C it was observed micro scopically that they remained unchanged in 0 7 solution shrank in more concentrated and swelled in more dilute solutions Water in 0 7 salt solution freezes at 0 406 C What is the osmotic pressure in atm of the cell cytoplasm at 25 C Kf for water 1 86 K kg mol

Mark the incorrect statement s a Potassium dichromate oxidises a secondary alcohol into a ketone b Potassium permanganate is a weaker oxidising agent than potassium dichromate c Potassium dichromate oxidises a secondary alcohol into aldehyde d Alkaline KMnO4 solution oxidises tertiary alcohol to of Irotone and cid

2 moles of a liquid A P 100 torr mixed with 4 moles of liquid B P 150 torr The first distillate obtained on fractional distillation of above mixture was then used as a solvent to prepare 2 molal solution of a non electrolyte and non volatile solute Vapour pressure of the resulting solution in torr is Take mola masses g mol M 100 M 80

0 2 M NaOH was gradually added to 200 mL 0 1 M HCI solution After complete neutralisation of the HCI addition of NaOH was stopped and 1 7 L of water was further added to dilute the final mixture What would be osmotic pressure in atm of the diluted mixture at 35 C Given that degree of dissociation of NaCl is 98 in water Take R 0 0821 atm L mol L

Which of the following figure correctly represent fractional distillation of a mixture of ethanol and propanol C V P P ethanol V P P ethanol mole fraction of ethanol V P 1 mole fraction of ethanol P propanol p propanol po ethanol

All 4 A 0 4K C 0 5 K Correct A 4 1 0 100g of a non electrolyte solute molar mass 250g mol was dissolved in 51 2g of benzene If the freezing point depression constant K of benzene is 5 12 K kg mol the freezing point of benzene will be lowered by A Incorrect B 0 3K 4 0 2 K Skip You Missed

7 A solution containing 8 6 g urea in one litre was found to be isotonic with 0 5 weight volume solution of an organic non volatile solute Calculate molar mass organic compound 4 1 0 A 33 50 g C 35 89 g A B A B B 34 89 g D 32 89 g You Missed

20 4 1 0 A solution was prepared by adding 125 cm of isopropyl alcohol to water until the volume of the solution was 175 cm Find the volume fraction and volume percent of isopropyl alcohol in the solution A 71 4 C 0 714 A A B B B 7 14 D None of these You Missed

A bottle of sparkling wine contains carbon dioxide at a pressure of 4 0 atm The solubility of carbon dioxide at 4 0 atm is 0 15 M When the bottle is opened the partial pressure of carbon dioxide drops to 4 0 x 104 atm Determine the solubility in M of carbon dioxide in wine at this pressure

9 4 1 0 A 5 solution of anhydrous CaCl at 0 C developed 15 atm osmotic pressure What is the degree of dissociation of CaCl A 22 33 C 21 33 A A B 24 33 D 25 33

At the equilibrium of the reaction X N O4 g 2 NO g MA Mo n 1 the observed molecular weight of N O4 is 80 g mol at 350 K The percentage of dissociation of N O4 g at 350 K is B 15 D 18 A 10 20 92 80 80 2 8 80

4 3 K CoCl 4 Na Ni CN 135 The solubility product of BaSO at 20 C is 1 x 10 What would be the concentration of H SO necessary to precipitate BaSO from a solution of 0 01MBa ions 1 10 2 10 3 107 4 10 2 K NICI 3 K CoCl 4 Na Ni CN 135 25 C fac Baso a fact 1 x 10 10 0 Baso fo H SO HD 1 10 3 10 2 10 8 4 10

3 N O 4 N O The molal elevation constant of water is 0 51 Km The boiling point of 0 1 molal aqueous NaCl solution is nearly 1 100 05 C 2 100 1 C 3 100 2 C 4 101 0 C 81 3 N 0 4 N O fis 0 51 Km 10 1 NaCl a face an am 1 100 05 C 2 100 1 C 3 100 2 C 4 101 0 C

All 3 Correct 4 1 0 A 250g mol C 350g mol Incorrect A solution containing 10g per dm of urea molecular mass 60g mol is isotonic with a 5 solution of a non volatile solute The molecular mass of this non volatile solute is A A Skip B 300g mol 4 200g mol

of react reaction A 2B Calculate AG in kJ mol for the reaction 1 A B 2 Standard molar enthalpy of combustion of glucose is 2880 kJ If only 25 of energy is available for muscular work and 10 km walk consumes 90 kJ of energy what maximum distance in km a person can walk after eating 90 g of glucose Given C H g H g C H g AH 175 kJ mol 201 3 C 2 AHC Hz 50 kJ mol AHHOD 280 kJ mol AH co 390 kJ mol f C H4 2 fAH is enthalpy of combustion in kJ mol of C H g then calculate the value of AH 257 rol ontholning of solution of anhydrous CuSO s and hydrated CuSO4 5H O s are

Vapour pressure of pure water at 25 C is 80 torr and that of an aqueous solution is 75 torr at the same temperature If K for water is 1 86K kg mol then freezing point of the solution is O 6 48 C 6 88 C O 6 99 C O 6 27 C

26 54 Select the correct statements regarding colligative properties of deal aqueous solutions Colligative properties are driven by entropy factor Colligative properties increases with mole fraction of water Colligative properties are independent of amount of the solution Colligative properties are independent of degree on ionization of the solute dissolved in water

Q 35 54 0 2 M NaOH was gradually added to 200 mL 0 1 M HCI solution After complete neutralisation of the HCI addition of NaOH was stopped and 1 7 L of water was further added to dilute the final mixture What would be osmotic pressure in atm of the diluted mixture at 35 C Given that degree of dissociation of NaCl is 98 in water Take R 0 0821 atm L mol L Answer

A sample of air containing 20 O2 and 80 N2 is dissolved in water when total pressure of air is 1 atm The solubility of N2 and O2 in terms of mole fraction is x and y This sample is taken at a height of H above sea level where pressure of air is 0 4 atm and temperature is 300 K and solubility of N2 and O2 in terms of mole fraction is x and y Assume that value of Henry s constant remains same at sea level and H The value of XY IS x y

2 To coagulate Agl Ag NO Sol The decreasing order of coagulation power in following is al NaCl b K SO4 d K Fe CN c d 3 4 d c b c Ca PO4 2 2 d c b a 4 d c a b

one of the properties of a solution is that A solution is always transparent in nature then why are alloys called solution i mean they are not transparent in nature for example brass is not transparent

For the reaction calculate how many grams of the product form when 24 4 of Sr completely reacts Assume that there is more than enough of the other reactant 267 AEO 2Sr s O g 2SrO s

Glucose form 3 different solution with water Solution A 10 w w Solution B 10 ppm Solution C 10 ppb Select correct option A Max mass of glucose present in solution A B Max mass of glucose present in solution B C Max mass of glucose present in solution C D Same mass of glucose in solution A B and C

9 Total vapour pressure of mixture of 1 mole of volatile component 69 a 2 P 100 mm Hg 3 A P 100 mm Hg and 3 mole of volatile component B iB p 80 mm Hg f P 80 mm Hg is 90 mm Hg For such case 90 mm Hg 1 fra fog 1 There is positive deviation from Raoult s law 1 2 Boiling point has been lowered 2 3 Force of attraction between A and B is smaller than 3 AB that between A and A or between B and B 4 All the above statements are correct 4 faca

8 Calculate the molality of an aqueous solution that has a boiling points elevation of 1 00 K For water K 0 512 K mol kg 9 When 36 0 g of a non volatile solute having the empirical formula CH O is dissolved in 1 20 kg of What is molecular formula of the compound

1 mole of anhydrous X is added in 1 Kg water volume is finally 1 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 1 CUS Q Conc HNO3 S R Hgl2 Kl s CH3COOH Ba OH 2 s List II Effect of addition of Y on X water mixture Freezing point decreases Osmotic pressure 2 does not increases Freezing point 3 does not increases Vapour pressure decreases

llustration 17 3 2 g of pyrolusite was treated with 50 mL of 0 5 M oxalic acid and some sulphuric acid The ox acid left undecomposed was raised to 250 mL in a flask 25 mL of this solution when treated 0 02 M KMnO4 required 32 mL of the solution Find the of MnO in the sample and also percentage of available oxygen plution