MCQ Questions Chapter 2 Solutions Class 12 Chemistry

Please refer to MCQ Questions Chapter 2 Solutions Class 12 Chemistry with answers provided below. These multiple-choice questions have been developed based on the latest NCERT book for class 12 Chemistry issued for the current academic year. We have provided MCQ Questions for Class 12 Chemistry for all chapters on our website. Students should learn the objective based questions for Chapter 2 Solutions in Class 12 Chemistry provided below to get more marks in exams.

Chapter 2 Solutions MCQ Questions

Please refer to the following Chapter 2 Solutions MCQ Questions Class 12 Chemistry with solutions for all important topics in the chapter.

MCQ Questions Answers for Chapter 2 Solutions Class 12 Chemistry

Question. The relative lowering of vapour pressure of an aqueous solution containing a non-volatile solute is 0.0125. The molality of the solution is
(a) 0.69 m
(b) 0.50 m
(c) 0.80 m 
(d) 0.40 m                 

Question. 25 mL of a solution of barium hydroxide on titration with 0.1 molar solution of hydrochloric acid gave a titre value of 35 mL. The molarity of barium hydroxide solution was
(a) 0.07 M
(b) 0.14 M
(c) 0.28 M
(d) 0.35 M           

Question. At 100°C, benzene and toluene have vapour pressure of 1375 torr and 558 torr, respectively. Assuming, these two form an ideal binary solution, then calculate the mole fraction of benzene in vapour phase at 1 atm and 100°C?
(a) 0.247
(b) 0.753
(c) 0.447            
(d) 0.553           

Question. The vapour pressure of water at 20°C is 17.5 mm Hg. If 18 g glucose (C₆H₁₂O₆ ) is added to 178.2 g of water at 20°C, the vapour pressure of the resulting solution will be
(a) 16.500 mm Hg
(b) 17.325 mm Hg
(c) 17.675 mm Hg
(d) 15.750 mm Hg               

Question. The density (in g mL⁻¹ ) of a 3.60 M sulphuric acid solution having 29% H₂SO₄ 
(molar mass =  98 g mol⁻¹ )  by mass, will be
(a) 1.64
(b) 1.88
(c) 1.22
(d) 1.45     

Question. The Henry’s law constant for the solubility ofN2 gas in water at 298 K is10 105 . × atm. The mole fraction of N2 in air is 0.8. The number of moles of N2 from air dissolved in 10 moles of water at 298 K and 5 atm pressure is
(a) 4.0 × 10⁻⁴ 
(b) 4.0 × 10⁻⁵
(c) 5.0 × 10⁻⁴
(d) 4.0 × 10⁻⁶               

Question. The density of 3 M solution of sodium chloride is 1.252 g mL⁻¹. The molality of the solution will be
(molar mass, NaCl 58.5 g mol⁻¹ ) =  
(a) 2.60 m
(b) 2.18 m
(c) 2.79 m
(d) 3.00 m         

Question. During depression in freezing point of a solution, the following are in equilibrium
(a) liquid solvent, solid solvent
(b) liquid solvent, solid solute
(c) liquid solute, solid solute
(d) liquid solute, solid solvent             

Question. A 5.2 molal aqueous solution of methyl alcohol, CH₃OH is supplied. What is the mole fraction of methyl alcohol in the solution?
(a) 0.100 M
(b) 0.190 M
(c) 0.086 M
(d) 0.050 M           

Question. The molarity of a solution obtained by mixing 750 mL of 0.5 M HCl with 250 mL of 2 M HCl will be 
(a) 1.00 M
(b) 1.75 M
(c) 0.975 M
(d) 0.875 M         

Question. 12 g of a non-volatile solute dissolved in 108g of water produces the relative lowering of vapour pressure of 0.1. The molecular mass of the solute (in g mol⁻¹) is
(a) 80
(b) 60
(c) 20
(d) 40               

Question. An aqueous solution of 2% (wt/wt) non-volatile solute exerts a pressure of 1.004 bar at the boiling point of the solvent. What is the molecular mass of the solute?
(a) 0.3655
(b) 36.55
(c) 41.37
(d) 40.16           

Question. A binary liquid solution is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution?
(a) The solution formed is an ideal solution
(b) The solution is non-ideal, showing positive deviation from Raoult’s law
(c) The solution is non-ideal, showing negative deviation from Raoult’s law
(d) n-heptane shows positive deviation while ethanol show negative deviation from Raoult’s law         

Question. A one molal solution of sodium chloride has a density of 1.21 g mL⁻¹. The molarity of this solution is
(a) 4.15 M
(b) 1.143 M
(c) 2.95 M
(d) 3.15 M     

Question. A and B are ideal gases. The molecular weight of A and B are in the ratio of 1 : 4 . The pressure of a gas mixture containing equal weight of A and B is p atm. What is the partial pressure (in atm) of B in the mixture?
(a) p/5
(b) p/2
(c) p/2.5
(d) 3p/4                       

Question. Vapour pressure of pure benzene is 119 torr and that of toluene is 37.0 torr at the same temperature. Mole fraction of toluene in vapour phase, which is in equilibrium with a solution of benzene and toluene having a mole fraction of 0.50 will be 
(a) 0.137
(b) 0.237
(c) 0.435 
(d) 0.205       

Question. On mixing, heptane and octane form an ideal solution at 373 K, the vapour pressures of the two liquid components (heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressure of the solution obtained by mixing 25 g of heptane and 35 g of octane will be (molar mass of heptane = 100 g mol⁻¹ and of octane = 114 g mol⁻¹ )  . 
(a) 72.0 kPa
(b) 36.1 kPa
(c) 96.2 kPa
(d) 144.5 kPa     

Question. 18 g of glucose (C₆H₁₂O₆ ) 6 12 6 is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is 
(a) 76.0
(b) 752.4
(c) 759.0
(d) 7.6                 

Question. If two liquids A and B form minimum boiling azeotrope at some specific composition then ……….
(a) A—B interactions are stronger than those between A—A or B —B
(b) vapour pressure of solution increases because more number of molecules of liquids A and B can escape from the solution
(c) vapour pressure of solution decreases because less number of molecules of only one of the liquids escape from the solution
(d) A—B interactions are weaker than those between A—B or B —B         

Question. How many grams of methyl alcohol should be added to 10 L tank of water to prevent its freezing at 268 K?
(K_f for water is 1.86 K kg mol⁻¹ ) 
(a) 880.07 g
(b) 899.04 g
(c) 886.02 g
(d) 868.06 g             

Question. Kf for water is 1.86 K kg mol⁻¹. If your automobile radiator holds 1.0 kg of water, how many grams of ethylene glycol (C₂H₆O₂) you must add to get the freezing point of the solution lowered to − 2.8° C? 
(a) 72 g
(b) 93 g
(c) 39 g
(d) 27 g                 

Question. For a dilute solution containing 2.5 g of non-volatile, non-electrolyte solute in 100 g of water, the elevation in boiling point at 1 atm pressure is 2°C. Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressure of solution is (K_b = 0.76 K kg mol⁻¹ ) 
(a) 724
(b) 740
(c) 736
(d) 718             

Question. An unknown compound is immiscible with water. It is steam distilled at 98.0°C. At 98.0°C, p and p° H₂O are respectively 737 and 707 torr. This distillate was 75% by weight of water. The molecular weight of the unknown compound will be
(a) 318.15 g mo^l−1
(b) 300 g mol⁻¹
(c) 30 6 1 6.7 g mol ⁻¹
(d) None of these           

Question. The vapour pressure of acetone at 20°C is 185 torr. When 1.2 g of a non-volatile substance was dissolved in 100 g of acetone at 20 °C, its vapour pressure was 183 torr. The molar mass of the substance is
(a) 32
(b) 64
(c) 128
(d) 488             

Question. We have 3 aqueous solution of NaCl labelled as ‘A’, ‘B’ and ‘C’ with concentrations 0.1 M, 0.01 M and 0.001 M, respectively. The value of van’t Hoff factor for these solution will be in the order of
(a) i_A < i_B < i_C  
(b) i_A > i_B >i_C 
(c) i_A = i_B =i_C 
(d) i_A < i_B >i_C             

Question. The depression in freezing point of 0.01 M aqueous solution of urea, sodium chloride and sodium sulphate is in the ratio of
(a) 1 : 1 : 1
(b) 1 : 2 : 3
(c) 1 : 2 : 4
(d) 2 : 2 : 3           

Question. When 20 g of naphthoic acid (C₁₁H₈O₂ ) is dissolved in 50 g of benzene (K_f = − 1.72K kg mol⁻¹), a freezing point depression of 2 K is observed. The van’t Hoff factor (i) is
(a) 0.5
(b) 1
(c) 2
(d) 3           

Question. The molar mass of a solute c in g mol^−1. If its 1% solution is isotonic with 95% solution of cane sugar (molar mass = 342 g mol⁻¹) is
(a) 68.4
(b) 34.2
(c) 136.2
(d) 171.2         

Question. Which of the following liquid pairs shows a positive deviation from Raoult’s law?
(a) Water           — Hydrochloric acid
(b) Benzene       — Methanol
(c) Water            — Nitric acid
(d) Acetone        — Chloroform         

Question. The degree of dissociation (a) of a weak electrolyte, AxBy is related to van’t Hoff factor (i ) by the
expression 
(a) α = i − 1/ (x + y − 1)
(b) α = i − 1/ x + y + 1
(c) α = x + y − 1 / i − 1
(d) α = x + y + 1 / i − 1               

Question. 45 g of ethylene glycol (C₂H₆O₂ ) is mixed with 600 g of water, what is depression in freezing point? 
(a) 7.9 K
(b) 2.5 K
(c) 6.6 K
(d) 2.2 K

Question. Which one of the following solutions exhibits the maximum elevation in boiling point?
(a) 0.1 m NaCl
(b) 0.1 m FeCl₃
(c) 0.1 m CaCl₂
(d) 0.1 m BaCl₂

Question. The temperature at which the vapour pressure of a liquid becomes equal to external (atmospheric) pressure is its
(a) melting point
(b) sublimation point
(c) inversion point
(d) critical temperature
(e) boiling point

Question. Vapour pressure in mm Hg of0.I mole of urea in 180 g of water at 25° C is ( the vapow· pressw·e of water at 25° C is 24 mm Hg) 
(a) 2.376
(b) 20.76
(c) 23.76
(d) 24.76       

Question. Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is are
(a) ΔG is positive 
(b) ΔS_system is positive
(C) ΔS_surroundings = 0
(d) ΔH = 0     

Question. Identify the mixture that shows positive deviation from Raoult’s law. 
(a) CHCI₃ + (CH₃ )₂CO
(b) (CH₃ )₂CO+ C₆H₅NH
(c) CHCI₃ + C₆H₆
(d)(CH₃ )₂CO + CS₂
(e) C₆H₅N + CH₃COOH   

Question. On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressw·es of the two liquid components (heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressw·e of the solution obtained by mixing 25 g of heptane and 35 g of octane will be (molar mass of heptane = 100 g mol^-1 and ofoctane = 114 g mol^-1 ) .
(a) 72.0 kPa
(b) 36. l kPa
(c) 96.2 kPa
(d) 144.5 kPa         

Question. The vapour pressure of a pure liquid A is 40 mm Hg at 310 K. The vapour pressure of this liquid in a solution with liquid B is 32 mm Hg. What is the mole fraction of A in the solution if it obeys the Raoult’s law? 
(a) 0.5
(b) 0.6
(c) 0.7
(d) 0.8       

Question. Two liquids X and Y form an ideal solution at 300 K, vapour pressure of the solution containing 1 mol of X and 3, mo! of Y is 550 mm Hg. At the san1e temperature, if I mo! of Y is further added to this solution, vapour pressure of the solution increases by 10 mmHg. Vapour pressure (in mmHg) of X and Yin their pure states will be, respectively
(a) 200 and 300
(b) 300 and 400
(c) 400 and 600
(d) 500 and 600       

Question. At 80°C, the vapour pressure of pure liquid’ A ‘ is 520 mm Hg and that of pure liquid ‘B’ is 1000 mm Hg. If a mixture solution of ‘A’ and ‘B’ boils at 80°C and 1 atm pressure, the amount of’ A’ in the mixture is (1 atm = 760 mm Hg)
(a) 52 mole per cent 
(b) 34 mole per cent
(c) 48 mole per cent
(d) 50 mole per cent         

Question. An aqueous solution freezes at- 0.186° Cthen elevation in boiling point is (K_b = 0.512, K_f = 1.86) 
(a) 0.0512° C
(b) 100.0512°C
(c) – 0.0512° C
(d) None of these

Question. K1 for water is 1.86 K kg mol^-1 . If your automobile radiator holds 1.0 kg of water, how many grams of ethylene glycol (C₂H₆O₂ )must you add to get the freezing point of the solution lowered to – 2.8° C? 
(a) 72g
(b) 93g
(c) 39g
(d) 27g

Question. For a dilute solution containing 2.5 g of a non-volatile non-electrolyte solute in 100 g of water, the elevation in boiling point at 1 atrn pressure is 2° C Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressw·e (mm of Hg) of the solution is (take K_b = 0.76 K kg mol^-1)
(a) 724
(b) 740
(c) 736
(d) 718

Question. 1.2% NaCl solution is isotonic with 7.2% glucose solution. What will be the van’t Hoff factor ‘f for NaCl? 
(a) 0.5
(b) 1
(c) 2
(d) 6

Question. The relative lowering of vapour pressure of an aqueous solution containing a non-volatile solute is 0.0125. The molality of the solution is 
(a) 0.70
(b) 0.30
(c) 0.125
(d) 0.07

Question. Volume of 0.6 M NaOH required to neutralise 30cm³ of 0.4 M HCI is 
(a) 20cm³
(b) 40cm³
(c) 45cm³
(d) 30cm³

Question. The relative lowering of vapour pressure of a dilute solution is equal to mole fraction of solute present in the solution. Which of the following law is state this? 
(a) Henry law
(b) Avogadro’s law
(c) Raoult’s law
(d) Law of definite proportion

Question. Which one of the following aqueous solutions will exhibit highest boiling point?
(a) 0.01 M Na₂SO₄
(b) 0.01 M KNO₃
(c) 0.015 M urea
(d) 0.015 M glucose                 

Question. If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water (ΔT_f ), when 0.01 mole of sodium sulphate is dissolved in 1kg of water, is (K_f = 1.86 K kg mol₋₁ ) 
(a) 0.0372 K
(b) 0.0558 K
(c) 0.0744 K
(d) 0.0186 K             

Question. The vapour pressure of a solvent decreases by 10 mm of mercury, when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent, if the decrease in vapour pressure is to be 20 mm of mercury?
(a) 0.8
(b) 0.6
(c) 0.4 
(d) 0.7             

Question. A compound X undergoes tetramerisation in a given organic solvent. The van’t Hoff factor is
(a) 4.0
(b) 0.25
(c) 0.125
(d) 2.0               

Question. The freezing point of benzene decreases by 0.45°C when 0.2 g of acetic acid is added to 20 g of benzene. If acetic acid associates to form a dimer in benzene, percentage association of acetic acid in benzene will be (K_f for benzene = 5.12 K kgmol⁻¹) 
(a) 64.6 %
(b) 80.4 %
(c) 74.6 %
(d) 94.6 %             

Question. The molecular weight of benzoic acid in benzene is determined by depression in freezing point method corresponds to
(a) ionisation of benzoic acid
(b) dimerisation of benzoic acid
(c) trimerisation of benzoic acid
(d) solvation of benzoic acid             

Question. At 10°C, the osmotic pressure of urea solution is 500 mm Hg. The solution is diluted and the temperature is raised to 25°C. The osmotic pressure of dilute solution is 105.3 mm Hg at 25°C. The extent of dilution can be shown as
(a) V_final = 5 V_initial 
(b) V_initial > V_final 
(c) V_final = 4 V_initial 
(d) V_final = 6 V_initial           

Question. Which of the following aqueous solutions should have the highest boiling point?
(a) 1.0 M NaOH
(b) 1.0 M Na₂SO₄
(c) 1.0 M NH₄NO₃
(d) 1.0 M KNO₃               

Question. Ethylene glycol is used as an antifreeze in 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_f for water = 1.86 K kg mol⁻¹ and molar mass of ethylene glycol = 62 g mol⁻¹). 
(a) 800.00 g
(b) 204.30 g
(c) 400.00 g
(d) 304.60 g                   

Question. In a 0.2 molal aqueous solution of a weak acid HX, the degree of ionisation is 0.3. Taking Kf for water as 1.85 K kg mol⁻¹, the freezing point of the solution will be nearest to
(a) −0.360°C
(b) −0.260°C
(c) +0.480°C
(d) −0.481°C           

Question. To neutralise completely 20 mL of 0.1 M aqueous solution of phosphorus acid (H PO ), 3 3 the volume of 0.1 M aqueous KOH solution required is
(a) 10 mL
(b) 20 mL
(c) 40 mL
(d) 60 mL           

Question. An aqueous solution freezes at −0.186° C
( K_f 1.86 K kg mol⁻¹ ,K_b = 0.512 K kg mol⁻¹).  What is the elevation in boiling point ?
(a) 0.186°C
(b) 0.512°C
(c) 0.86°C
(d) 0.0512°C             

Question. When mercuric iodide is added to the aqueous solution of potassium iodide, the
(a) freezing point is raised
(b) freezing point is lowered
(c) freezing point does not change
(d) boiling point does not change           

Question. Consider separate solution of 0.500 M C₂H₅OH (aq), 0.100M Mg₃ (PO₄)₂(aq), 0.250M KBr(aq) and 0.125 MNa₃PO₄ (aq) at 25° C. Which statement is true about these solution, assuming all salts to be strong electrolytes? 
(a) They all have the same osmotic pressure
(b) 0.100M Mg₃ (PO₄ )₂ aq has the highest osmotic pressure
(c) 0.125 M Na₃PO₄ (aq) has the highest osmotic pressure
(d) 0.500 M C₂H₂OH(aq) has the highest osmotic pressure           

Question. The elevation in boiling point of a solution of 13.44 g of CuCl₂ in 1 kg of water using the following information will be (molecular weight of CuCl₂ =134.4 and
K_b = 0.52 K mol⁻¹ ) 
(a) 0.16
(b) 0.05
(c) 0.1  
(d) 0.2               

Question. Two liquids X andY form an ideal solution at 300 K, vapour pressure of the solution containing 1 mole of X and 3 moles ofY is 550 mm Hg. At the same temperature, if 1 mole ofY is further added to this
solution, vapour pressure of the solution increases by 10 mm Hg. Vapour pressure (in mm Hg) of X andY in their pure states will be, respectively
(a) 200 and 300
(b) 300 and 400
(c) 400 and 600
(d) 500 and 600         

Question. 58.5 g of NaCl and 180 g of glucose were separately dissolved in 1000 mL of water. Identify the correct statement regarding the elevation of boiling point (b.p.) of the resulting solutions.
(a) NaCl solution will show higher elevation of boiling point
(b) Glucose solution will show higher elevation of boiling point
(c) Both the solutions will show equal elevation of boiling point
(d) The boiling point elevation will be shown by neither of the solution           

Question. How many mL of 0.1 M HCl are required to react completely with 1g mixture of Na2CO₃ and NaHCO3 containing equimolar amount of these two?
(a) 157.8 mL
(b) 0.1578 mL
(c) 210.4 mL
(d) 105.2 mL         

Question. The vapour pressure of benzene at a certain temperature is 640 mm Hg. A non-volatile, non-electrolyte solute weighing 2.175 g, is added to 39.0 g of benzene. The vapour pressure of the solution is 600 mm Hg. What is the molecular weight of the solid substance?
(a) 6.96
(b) 65.3
(c) 63.8
(d) None of the above               

Question. Which one of the following statements is false?
(a) Raoult’s law states that the vapour pressure of a component over a solution is proportional to its mole fraction
(b) The osmotic pressure (π) of a solution is given by the equation π = MRT , whereM is the molarity of the solution
(c) The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl₂ > KCl > CH₃COOH > sucrose
(d) Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression         

Question. In comparison to a 0.01M solution of glucose, the depression in freezing point of a 0.01M MgCl₂ solution is ……….
(a) the same
(b) about twice
(c) about three times
(d) about six times         

Question. At 310 K, the vapour pressure of an ideal solution containing 2 moles of A and 3 moles of B is 550 mm of Hg. At the same pressure if one mole of B is added to this solution, the vapour pressure of solution increased by 10 mm of Hg. What is the vapour pressure of A in its pure state?
(a) 460 mm
(b) 610 mm
(c) 360 mm
(d) 750 mm             

Question. The freezing point (in °C) of a solution containing 0.1 g of K₃ [ Fe(CN)₆ ] (mol. wt. 329 gmol⁻¹) in 100 g of water  (Kf = .86 K kg mol⁻¹ )  is
(a) −  2.3 × 10⁻²
(b) −  5.7 × 10⁻²
(c) −  5.7 × 10⁻³
(d) − 1.2 × 10⁻²           

Question. Sea water is found to contain 5.85% NaCl and 9.5%MgCl₂ by weight of solution. Calculate its normal boiling point assuming 70% ionisation for NaCl and 50% ionisation of MgCl₂ [K_b (H₂O) = 0.51 K kg mol⁻¹ ]  
(a) 101.4°C
(b) 102.29°C
(c) 103.27°C
 (d) 99.46°C               

Question. 10 mL of 2 M NaOH solution is added to 200 mL of 0.5 M of NaOH solution. What is the final concentration?
(a) 0.57 M
(b) 5.7 M
(c) 11.4 M
(d) 1.14 M     

Question. For 1 molal aqueous solution of the following compounds, which one will show the highest freezing point?
(a) [Co(H₂O)₆ ]Cl₃
(b) [Co(H₂O)₅ Cl]Cl₂ H₂O 
(c) [Co(H₂O)₄ Cl₂ ]Cl 2H₂O 
(d) [Co(H₂O)₃ Cl₃ ] 3H₂O           

Question. A 0.001 molal solution of [Pt(NH₃)₄ Cl₄ ] in water had a freezing point depression of 0.0054° C. If Kf for water is 1.80, the correct formulation of the above molecule is
(a) [Pt(NH₃)₄ Cl₃]Cl 
(b) [Pt(NH₃)₄ Cl₂]Cl₂
(c) [Pt(NH₃)₄ Cl]Cl₃
(d) [Pt(NH₃)₄ Cl₄]Cl               

Question. The density of a solution prepared by dissolving 120 g of urea (mol. mass = 60 u) in 1000 g of water is 1.15 g/mL. The molarity of this solution is 
(a) 0.50 M
(b) 1.78 M
(c) 1.02 M
(d) 2.05 M       

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