1. No category

Dr. Vikram Panchal
Institute Of Chemistry
WORKSHEET-1 [JEE / NEET]
Solution
Q1. Calculate the masses of sugarcane & water required to
prepare 250 g of 25% cane sugar solution.
Q2. Calculate the molarity of the following solutions:
(a) 4 g of caustic soda dissolved in 200 mL of the solution.
(b) 5.3 g of anhydrous sodium carbonate is dissolved in
100 mL of solution.
(c) 0.365 g of pure HCl gas dissolved in 50mL of solution.
Q3. The density of a solution containing 13% by mass of
sulphuric acid is 1.09 g/mL. Calculate the molarity &
normality of the solution.
Q4. Calculate the molarity of pure water. (d=1g/mL)
Q5. Calculate the quantity of sodium carbonate
(anhydrous) required to prepare 250mL solution.
Q6. 214.2 g of sugar syrup contains 34.2 g of sugar.
Calculate molality & mole fraction of sugar syrup.
Q7. A solution contains 410.3 g of H2SO4 per lit of solution
at 20C. If the density is 1.243 g/mL. What will be its
molarity & molality?
Q8. The density of a 2.03 M solution of acetic acid (mol
mass = 60) in water is 1.017 g/mL . Calculate the molality
of the solution.
Q9. The density of a 3 M sodium thiosulphate (Na2S2O3)
solution is 1.25 g/mL. Calculate the percentage by mass, of
Na2S2O3 mole fraction of Na2S2O3 & molalities of Na+ &
S2O32- ions .
Q10. A solution is prepared by dissolving 5.64 g of glucose
in 60 g of water. Calculate the following
(a) Mass percentage of each of glucose & water (b)
molality of solution.
(c) Mole fraction of each of glucose & water
Q11. What would be the molality of a solution made by
mixing equal volume of 30% by mass of H2SO4
(d=1.218g/cm3) & 70% by mass H2SO4 (d=1.61g/cm3) ?
Q12. The mole fraction of CH3OH in aqueous solution is
0.02 & its density is 0.994g/cm3. Determine the molarity &
molality.
Q13. Calculate the concentration of NaOH solution in g/mL,
which has same normality as that of a solution of HCl of
concentration 0.04 g /mL.
Q14. How many Na+ ions are present in 50mL of a 0.5 M
solution of NaCl?
Q15. Reaction
2Br-(aq) + Cl2 (aq)  2Cl-(aq) + Br2 (aq) is used
for commercial preparation of bromine from its salts .
Suppose we have 50 mL of 0.06M solution of NaBr. What
volume of a 0.05 M solution of Cl2 is needed to react
completely with the Br- ?
Q16. Calculate the molarity , molality & mole fraction of
ethyl alcohol in a solution of total volume 95 mL prepared
by adding 50 mL of ethyl alcohol (d=0.789 g/mL ) to 50 mL
water (d=1g/mL).
Q17. Calculate the concentration of CO2 in a soft drink that
is bottled at partial pressure of CO2 of 4 atm over the liquid
at 25C. The Henry’s Law constant for CO2 in water at 25C
is 3.1x10-2 mol/lit.atm
Q18. The partial pressure of ethane over a saturated
solution containing 6.56 x 10-2 g of ethane is 1 bar. If the
solution contains 5 x 10-2 g of ethane, then what shall be
the partial pressure of the gas?
Q19. The vapour pressure of ethanol & methanol are
44.5mm & 88.7 mm Hg respectively. An ideal solution is
formed at same temperature by mixing 60 g of ethanol
with 40 g of methanol. Calculate the total vapour pressure
of the solution & mole fraction of methanol in vapour.
Q20. Two liquids A & B form an ideal solution At 300K the
vapor pressure of the solution containing 1 mole of A & 3
mole of B is 550 mm of Hg at the same temperature, if 1
more mole of B is added to this solution, the vapour
pressure of this solution increases by 10mm of Hg .
Determine the vapour pressure of A & B in their pure state.
Q21. An aqueous solution containing 28% by mass of a
liquid A (mol mass=140) has a vapour pressure of 160 mm
at 37C. Find the vapour pressure of the pure liquid A (the
vapour pressure of water at 37C =150mm )
Q22. Heptane & octane form ideal solution at 373 K, the
vapour pressure of the two liquids are 105.2 kPa & 46.8
kPa respectively what will be the vapour pressure, in bars ,
of a mixture of 25g of heptane & 35g of octane ?
Q23. 50g of a saturated aqueous solution of potassium
chloride at 30C is evaporated to dryness, when 13.2 g of
dry KCl was obtained. Calculate the solubility of KCl in
water at 30C
Q24. How much copper sulfate will be required to saturate
100 g of dilute aqueous solution of CuSO4 at 25C if 10 g of
the dilute solution leave on evaporation & drying 1.2 g of
anhydrous CuSO4? The solubility of CuSO4 in water at 25C
is 25.
Q25. Calculate the vapour pressure lowering caused by
addition of 50 g of sucrose (molecular mass= 342) to 500 g
of water if the vapour pressure of pure water at 25C is
23.8mm of Hg.
Q26.The vapour pressure of the pure benzene at a certain
temperature is 640mm Hg. A non volatile solid weighting
2.175 g is added to 39 g of benzene. The vapour pressure
of the solution is 600 mm of Hg. What is the mol. Mass of
the solid substance?
Q27. A solution Containing 30g of a non volatile solute is
exactly 90g of water has vapour pressure of 21.85 mm Hg
at 25C. Further, 18g of water is then added to the
solution; the new vapour pressure becomes 22.15 mm of
Hg at 25C. Calculate the (a) molecular mass of solute & (b)
vapour pressure of water at 25C.
Q28. What mass of non volatile solute (urea) needs to be
dissolved in 100g of water in order to decrease the vapour
pressure of water by 25%? What will be the molality of the
solution?
Q29. A current of dry air was bubbled through a bulb
containing 26.66g of an organic compound in 200 g of
water, then through a bulb at the same temperature ,
containing water & finally through a tube containing
anhydrous calcium chloride. The loss of mass in bulb
containing water was 0.087 g & gain in mass of the calcium
chloride tube was 2.036 g. Calculate the molecular mass of
the organic substance.
Q30. The vapour pressure of a dilute aqueous solution Of
glucose is 750mm Hg at 373K. Calculate molality & mole
fraction of the solute
Q31. Calculate the vapour pressure of an aqueous solution
which contain 5 mass percent of urea. The vapour
pressure of pure water is 23.5mm Hg. Molar mass of urea
is 60.
Q32. 10g of glucose (mol mass=108) & 20 g of sucrose
(mol. Mass =342) are dissolved in 100 g of water. What
will be the vapour pressure of the resultant sol if the
vapour pressure of water is 35mm Hg?
Q33. Calculate the vapour pressure of aqueous solution of
1 m glucose solution at 100C
Q34. The vapour pressure of pure benzene at 50C is
268mm of Hg . How many mole of non volatile solute per
mole of benzene are required to prepare a solution Of
benzene having a vapour pressure 167 mm of Hg at 50C ?
Q35. On dissolving 10.8 g glucose (m. wt. =180) in 240 g of
water, its boiling point increases by 0.13C. Calculate the
molal elevation constant of water.
Q36. A solution of a non volatile solid in 100 g benzene is
boiled at 0.42C higher than the boiling point of pure
benzene. Calculate the molecular mass of the substance.
Molal elevation constant of benzene is 2.67Kg/mol
Q37. The molal elevation constant for water is 0.56Kg/mol.
Calculate the boiling point of a solution made by dissolving
60 g of urea in 200 g of water.
Q38. By dissolving 13.6 g of a substance in 20g of water,
the freezing point decreases by 3.7C. calculate the
molecular mass of the substance. (Molal depression
constant for water =1.863K kg/mol)
Q39. On dissolving 0.25 g of a nonvolatile substance in 30
mL benzene (d=0.8g/mL), its freezing point decreases by
0.4C. Calculate the molecular mass of non volatile
substance (Kf =5.12K kg/mol)
Q40. A solution of 1.25 g of a certain non volatile substance
in 20g of water freezes at 271.94 K. Calculate the
molecular mass of the solute (Kf =1.86K kg/mol )
Q41. Two elements A & B form compounds having
molecular formulae AB2 & AB4. When dissolved in 20 g of
benzene, 1 g of AB2 lowers the freezing point by 2.3C,
whereas 1g AB4 lowers the freezing point by 1.3C. The
molal depression constant for benzene in 1000 g is 5.1.
Calculate the atomic masses of A & B?
Q42. 1.355 g of a substance dissolved in 55 g of CH3COOH
produced a depression in the freezing point of 0.618C
Calculate the molecular weight of the substance (Kf = 3.85 )
Q43. An aqueous solution of a non volatile solute boils at
100.17C. At what temperature will the solution freeze?
(Given: Kb=0.512K kg/mol & Kf =1.86K Kg/mol)
Q44. 18 g of glucose is dissolved in 1 Kg of water in a
saucepan. At what temperature will the water boil? (1.013
bar pressure)? Kb of water =0.52K kg/mol.
Q45. A solution of urea in water has boiling point of
100.15C. Calculate the freezing point of the same solution
if Kf & Kb for water are 1.876K kg/mol & 0.52K kg/mol
resp.
Q46. In a cold climate, water gets frozen causing damage to
the radiator of a car. Ethylene glycol is used as an anti
freezing agent. Calculate the amount of ethylene glycol to
be added to 4 kg water to prevent it from freezing at -6C
(Kf of water = 1.85 K kg/mol)
Q47. A solution Containing 0.2563 g of naphthalene ( mol
mass =128 ) in 50 g of carbon tetrachloride yields a boiling
point elevation of 0.201C while a solution Of 0.6216 g of
an unknown solute in same mass of the solvent gives a
boiling point elevation of 0.647C . Find the molecular
mass of the unknown solute.
Q48. 200cm3 of an aqueous solution contains 1.26 g of a
polymer. The osmotic pressure of such solution is 300K is
found to be 2.57x10-3 bar. Calculate the molar mass of the
polymer.
Q49. A solution is prepared by dissolving 1.08 g of human
serum albumin, a protein obtained from blood plasma, in
50 cm3 of aqueous solution The solution has an osmotic
pressure of 5.85 mm Hg at 298K:
(a) What is molar mass of albumin?
(b) What is the
height of water column placed in solution? [density of
water = 1 gm cm-3]
Q50. Calculate the osmotic pressure of 5% solution of cane
sugar (sucrose) at 15C?
Q51. The solution containing 10g of an organic compound
per litre Showed an osmotic pressure of 1.18 atm. at 0C.
Calc the molecular mass of the compound (S=0.0821 lit.
atm. Per degree per mol)
Q52. The osmotic pressure of a solution containing 30 g of
a substance in 1 litre of solution at 20C is 3.2 atm.
Calculate the value of S & molar mass of solute is 228
Q53. What is the volume of the solution Containing 1 g
mole of sugar that will give raise to an osmotic pressure of
1 atm. at 0C?
Q54. Find the osmotic pressure of M/20 solution of urea at
27C(R=0.0821 lit atm/K mol)
Q55. The osmotic pressure of a solution of an organic
substance containing 18g in 1 litre of solution at 293K is
2.414x105 N/m2. Find the molecular mass of the substance
if R = 8.3 J/Kmol.
Q56. A 5% solution of cane sugar is isotonic with 0.877%
solution of urea. Calculate the molecular mass of urea if the
molecular mass of cane sugar is 342.
Q57. Phenol associates in benzene to a certain extent for a
dimer. A solution containing 20x10-3 kg of phenol in 1 kg of
benzene has its freezing point decrease by 0.69 K. Calc the
fraction of phenol that has dimerised (Kf of benzene =
5.12K kg/mol )
Q58. The freezing point depression of 0.001m Kx[Fe(CN)6]
is 7.1x10-3 K . Determine the value of x. (Kf of water= 1.86
K kg/mol)
Q59. A solution of potassium ferrocyanide is 46%
dissociated at 18C. What will be its osmotic pressure?
Q60. A 0.5% aqueous solution Of KCl was found to freeze
at -0.24C. Calc the Van’t hoff factor & degree of
dissociation of the solute at this concentration (Kf of
water=1.86 K kg/mol)
Q61. The freezing point of a solution containing 0.2 g of
acetic acid in 20g of benzene id lowered down by 0.45C.
Calculate the degree of association of acetic acid in
benzene (Kf of benzene = 5.12 K kg/mol)