1. For a 1 molar solution of NaCl in water at 25°C and 1 atm pressure
Molarity = Normality Molality = Normality Molality = Mole fraction Molarity = Mole fraction (a ) For NaCl (1:1 electrolyte), Molarity = Normality (since n-factor = 1) 2. Which of the following modes of expressing concentration is independent of temperature?
Molarity Molality Formality Normality (b ) Molality depends on mass (kg of solvent) which doesn't change with temperature 3. Molarity is expressed as
Grams/litre Litres/mole Moles/litre Moles/1000 gm (c ) Molarity = moles of solute per liter of solution 4. A molal solution is one that contains one mole of a solute in
1000 gm of the solvent One litre of the solvent One litre of the solution 22.4 litre of the solution (a ) Molality = moles of solute per kg of solvent 5. The solubility of a gas in water depends on
nature of the gas temperature pressure of the gas all the above (d ) Gas solubility depends on nature (Henry's law), temperature (↓ solubility with ↑ temp), and pressure (↑ solubility with ↑ pressure) 6. The volume of a 0.2 N base required to completely react with 0.5 litre of an 0.1 N acid is
(c ) N1 V1 = N2 V2 → 0.1 × 0.5 = 0.2 × V → V = 0.25 L 7. How many grams of CH3 OH would have to be added to water to prepare 150 mL of a solution that is 2.0 M CH3 OH?
9.6 g 2.4 g 9.6 × 103 g 4.3 × 102 g (a ) Moles = 2.0 × 0.15 = 0.3 mol; Mass = 0.3 × 32 = 9.6 g 8. Which one of the following gases contains least number of molecules?
4 g of H2 2 g of marsh gas (CH4 ) 4 g of PCl5 2 g of phosgene (COCl2 ) (d ) 2g COCl2 (MW=99) = 0.02 mol; others have more moles (H2 =2mol, CH4 =0.125mol, PCl5 =0.019mol) 9. 5.85 g of NaCl is dissolved in H2 O and solution made upto 500 mL. The molarity is
(b ) Moles = 5.85/58.5 = 0.1; Molarity = 0.1/0.5 = 0.2 M 10. What is the molarity of H2 SO4 solution that has a density of 1.84 g/cc at 35°C and contains 98% by weight?
(d ) For 1L solution: mass = 1840g → H2 SO4 mass = 1803.2g → moles = 18.4 → Molarity = 18.4 M 11. An aqueous solution of glucose is 10% in strength. The volume in which 1 gm mole of it is dissolved will be
18 litres 9 litres 0.9 litre 1.8 litres (d ) 10% solution = 10g/100mL; For 180g (1 mole): Volume = (100×180)/10 = 1800 mL = 1.8 L 12. A 500 g tooth paste sample has 0.2 g fluoride concentration. What is the concentration of F in terms of ppm level? [BPKIHS ]
250 ppm 200 ppm 400 ppm 100 ppm (c ) ppm = (0.2/500) × 106 = 400 ppm 13. Increasing the temperature of an aqueous solution will cause
decrease in molality decrease in molarity decrease in mole fraction decrease in % w/w (b ) Molarity depends on volume which increases with temperature 14. 10 mL of N-HCl, 20 mL of N/2 H2 SO4 , and 30 mL of N/3 HNO3 are mixed together and volume made to one litre. The normality of the resulting solution is
(d ) Total equivalents = (10×1) + (20×0.5) + (30×0.33) = 30; N = 30/1000 = 0.03 = N/40 15. What is the normality of 1 M solution of H3 PO4 ?
(d ) For complete neutralization (3 H+ ), Normality = 3 × Molarity 16. Normality of 2 M sulphuric acid is
(b ) H2 SO4 has n-factor 2 → Normality = 2 × 2 = 4 N 17. How many grams of dibasic acid (Mol. wt 200) should be present in 100 mL of its aqueous solution to give decinormal strength?
(a ) Decinormal = 0.1 N; For dibasic acid: 0.1 N = 0.05 M → mass = 0.05 × 0.1 × 200 = 1 g 18. Sum of mole fractions of the two components of a binary solution is always
More than one Less than one Exactly one Not fixed (c ) XA + XB = 1 by definition 19. The molarity of pure water is [BPKIHS 2008 ]
(a ) 1000g water = 55.6 moles in 1L → 55.6 M 20. The number of moles in 180 g of water is [Ind. Emb. 2009 ]
1 mole 5 moles 10 moles 18 moles 21. If we take 44 g of CO2 and 14 g of N2 , what will be mole fraction of CO2 in the mixture?
(b ) Moles: CO2 =1, N2 =0.5 → XCO2 =1/1.5=2/3 22. Which is heaviest?
25 g of Hg 2 moles of H2 O 2 moles of CO2 4 g atoms of O2 (c ) 2 moles CO2 = 88 g (others: Hg=25g, H2 O=36g, O2 =128g) 23. The temperature at which the vapour pressure is equal to the external pressure is called the
Critical temperature Boiling point Normal point Saturation point (b ) Definition of boiling point 24. A substance will be deliquescent if its vapour pressure is
Greater than that of water vapour in the air Less than that of water vapour in the air Equal to that of water vapour in the air Equal to the atmospheric pressure (b ) Deliquescent substances absorb moisture from air when their VP < air's water VP 25. Azeotropic mixtures are
Constant boiling mixtures Those which boil at different temperatures Mixture of two solids None of the above (a ) Azeotropes boil at constant temperature with unchanged composition 26. Colligative properties of the solution depend on
Nature of solute Nature of solvent Number of particles present in the solution Number of moles of solvent only (c ) Colligative properties depend on solute particle concentration 27. Identify the mixture that shows positive deviation from Raoult's law
CHCl3 + (CH3 )2 CO (CH3 )2 CO + C6 H5 NH2 CHCl3 + C6 H6 (CH3 )2 CO + CS2 (d ) Acetone + CS2 shows positive deviation (weaker interactions than pure components) 28. Which of the following is not a colligative property?
Osmotic pressure Elevation of b.p. Depression of f.p. Vapour pressure (d ) Vapour pressure itself isn't colligative (but its lowering is) 29. Which is not a colligative property?
Freezing point Lowering of vapour pressure Depression of freezing point Elevation of boiling point (a ) Freezing point itself isn't colligative (its depression is) 30. Which of the following is a colligative property?
Surface tension Viscosity Boiling point Osmotic pressure (d ) Osmotic pressure depends on solute particle concentration 31. For a dilute solution, Raoult's law states that
The lowering of vapour pressure is equal to the mole fraction of the solute The relative lowering of vapour pressure is equal to the mole fraction of the solute The relative lowering of vapour pressure is proportional to the amount of solute in solution The vapour pressure of the solution is equal to the mole fraction of the solvent (b ) Raoult's law: (P°-P)/P° = Xsolute 32. A solution that obeys Raoult's law is
normal molar ideal saturated (c ) Ideal solutions obey Raoult's law 33. A mixture of benzene and toluene forms
an ideal solution a non-ideal solution a suspension an emulsion (a ) Benzene-toluene forms nearly ideal solution 34. Which of the following liquid pairs shows a positive deviation from Raoult's law?
Water-hydrochloric acid Water-nitric acid Acetone-chloroform Benzene-methanol (d ) Benzene-methanol shows positive deviation (weaker interactions) 35. Which of the following pairs shows a negative deviation from Raoult's law?
Acetone-benzene Acetone-ethanol Acetone-chloroform Benzene-methanol (c ) Acetone-chloroform forms H-bonds → negative deviation 36. If liquid A and B form an ideal solution
the enthalpy of mixing is zero the entropy of mixing is zero the free energy of mixing is zero the free energy as well as the entropy of mixing is zero (a ) For ideal solutions: ΔHmix = 0, ΔSmix > 0 37. Which one of the following solutions would produce maximum elevation in B.P.?
0.1 M glucose 0.2 M sucrose 0.1 M BaCl2 0.1 M MgSO4 (c ) BaCl2 gives 3 ions (i=3) → highest ΔTb 38. Which of the following solutions will have the highest boiling point?
1% glucose 1% sucrose 1% NaCl 1% CaCl2 (d ) CaCl2 gives most particles (i=3) → highest boiling point elevation 39. Semipermeable membrane is that which permits the passage of
Solute molecules only Solvent molecules only Solute and solvent molecules both Neither solute nor solvent molecules (b ) Semipermeable membranes allow only solvent molecules to pass 40. Which inorganic precipitate acts as semipermeable membrane?
Calcium sulphate Barium oxalate Nickel phosphate Copper ferrocyanide (d ) Cu2 [Fe(CN)6 ] acts as semipermeable membrane 41. When a few typical solutes are separated by a particular selective membrane such as protein particles, blood corpuscles, this process is called
dialysis diffusion transpiration endosmosis (a ) Dialysis separates colloids from crystalloids using semipermeable membrane 42. As a result of osmosis the volume of the solution
gradually decreases gradually increases is not effected any of the three (b ) Osmosis causes solvent flow into solution → volume increases 43. Osmotic pressure is measured quickly and accurately by
Berkeley and Hartley method Morse's method Pfeffer's method De Vries method (a ) Berkeley-Hartley method is most accurate for osmotic pressure measurement 44. The osmotic pressure of a solution is given by the relation
π = ST/C π = CT/S π = SC/T π/C = ST (c ) πV = nST → π = nST/V = CST (where C=n/V) 45. The osmotic pressure of solution increases if
Temperature is decreased Solution constant is increased Number of solute molecules is increased Volume is increased (c ) π = nRT/V → increases with more solute particles (n) 46. Osmotic pressure of a sugar solution at 24°C is 2.5 atmosphere. The concentration of the solution in gm mole per litre is
(d ) π = CRT → C = π/RT = 2.5/(0.0821×297) ≈ 0.1025 M 47. The osmotic pressures of equimolar solutions of BaCl2 , NaCl and sucrose will be in the order
Sucrose > NaCl > BaCl2 Sucrose > BaCl2 > NaCl NaCl > BaCl2 > Sucrose BaCl2 > NaCl > Sucrose (d ) π = iCRT; i(BaCl2 )=3, i(NaCl)=2, i(sucrose)=1 → BaCl2 > NaCl > sucrose 48. Solutions with same osmotic pressure are called
Hypertonic Hypotonic Isotonic Normal (c ) Isotonic solutions have equal osmotic pressure 49. Van't Hoff factor for an electrolyte is
(a ) Electrolytes dissociate → i > 1 (for non-electrolytes i=1) 50. Acetic acid dissolved in benzene shows a molecular mass of
(c ) Dimerization in benzene → apparent MW = 2×60 = 120 51. Pressure cooker reduces cooking time because
The heat is more evenly distributed The higher pressure tenderizes the food The boiling point of water inside is elevated A larger flame is used (c ) Increased pressure raises boiling point → faster cooking 52. Maximum freezing point falls in
Camphor Naphthalene Benzene Water (a ) Camphor has highest cryoscopic constant (Kf =40) 53. The molality of a solution having 18 g of glucose (mol. wt. = 180) dissolved in 500 g of water will be
(c ) Molality = (18/180)/0.5 = 0.2 m 54. Which one of the following is not an ideal solution?
C6 H5 Br and C6 H5 I mixture C6 H5 Cl and C6 H5 Br mixture C6 H6 and C2 H4 Cl2 mixture C2 H5 I and C2 H5 OH mixture (d ) Ethanol-iodoethane shows non-ideal behavior due to different intermolecular forces 55. Dialysis can separate
glucose and fructose glucose and sucrose glucose and NaCl glucose and proteins (d ) Dialysis separates colloids (proteins) from crystalloids (glucose) 56. Number of moles of a solute per kilogram of a solvent is called
Molarity Molality Normality Formality (b ) Definition of molality 57. Units of mole fraction are
moles/L moles/kg moles litre dimensionless (d ) Mole fraction is ratio of moles → unitless 58. Calculate the normality of 10 volume H2 O2
(a ) 10 vol H2 O2 ≈ 3% w/v ≈ 0.88 M ≈ 1.76 N (as n=2) 59. Which of the following colligative properties can provide molar mass of proteins with greatest precision?
Elevation of boiling point Depression of freezing point Osmotic pressure Relative lowering of vapour pressure (c ) Osmotic pressure is most sensitive for large molecules like proteins 60. Camphor is often used in molecular mass determination because [BPKIHS, IOM ]
it is readily available it has very high cryoscopic constant it is volatile it is solvent for organic substances (b ) High Kf (40 K kg mol-1 ) gives measurable ΔT even for small concentrations 61. Which of the following concentration terms is/are independent of temperature:
molarity molarity and mole fraction mole fraction and molality only molality (c ) Mole fraction and molality don't depend on volume (temperature independent) 62. Which has the minimum freezing point?
One molal KCl aq. solution One molal CaCl2 aq. solution One molal NaCl aq. solution One molal urea aq. solution (b ) CaCl2 gives most particles (i=3) → greatest freezing point depression 63. Which one of the following is not correct for an ideal solution?
ΔH = 0 It must obey Raoult's law ΔV = 0 ΔH = ΔV ≠ 0 (d ) For ideal solutions: ΔH = 0 and ΔV = 0 64. Which of the following solutions will exhibit highest boiling point?
0.01 M Na2 SO4 (aq) 0.01 M KNO3 (aq) 0.015 M urea (aq) 0.015 M glucose (aq) (a ) Na2 SO4 gives 3 ions → highest boiling point elevation 65. Which of the following is not a non-electrolyte?
Acetic acid Glucose Urea Ethanol (a ) Acetic acid partially dissociates (weak electrolyte) 66. During depression of freezing point in a solution which of the following are in equilibrium
Liquid and solid solute Liquid and solid solvent Liquid solute and solid solvent Liquid solvent and solid solute (b ) Freezing point depression involves solvent equilibrium (liquid solvent ⇌ solid solvent) 67. A solution of sodium metal in liquid NH3 gets reduced due to presence of:
Sodium amide Sodium atom Sodium hydroxide Solvated electrons (d ) Blue color of Na/NH3 solution due to solvated electrons (e-(NH3 )x ) 