Solutions NEET MCQ

Answer:d) They are independent of the nature of both the solute and solvent. (Colligative properties of a solution, such as boiling point elevation, freezing point depression, osmotic pressure, and vapor pressure lowering, depend only on the number of solute particles present in the solution, and not on their chemical nature.)

Answer:c) Surface area of the solid solute. (The solubility of a solid solute in a liquid solvent is affected by temperature, pressure (in the case of gases), and the nature of both the solute and solvent. However, the surface area of the solid solute does not have any significant effect on solubility.).

Answer:d) 0.2 M CaCl2 (Osmotic pressure is directly proportional to the concentration of solute particles in solution, and CaCl2 dissociates into three particles in solution (one Ca2+ ion and two Cl- ions), whereas NaCl dissociates into two particles (one Na+ ion and one Cl- ion). Therefore, a 0.2 M CaCl2 solution will have a higher osmotic pressure than any of the other options.)

Answer:c) The solute and solvent molecules should be of similar sizes. (Raoult’s law assumes that the solute and solvent molecules are of similar sizes and have similar intermolecular forces. This assumption may not hold true for all solutes and solvents, especially in cases where there is a significant difference in molecular sizes or intermolecular forces. However, this is not a limitation of Raoult’s law as such, but rather a limitation of its applicability in certain cases.)

Answer:b) It holds true only for dilute solutions. (Henry’s law is valid only for dilute solutions, where the solute concentration is much lower than the solvent concentration. It is an empirical law and does not take into account the non-ideality of solutions.)

Answer:d) 2.0 m. (The relation between mole fraction and molality is given by: molality = (mole fraction of solute) / (solvent’s molal constant). Since the molal constant for water is approximately 1000 g/mol, we have: molality = (0.2) / 1000 = 0.0002 mol/g. Since 1 liter of water weighs approximately 1000 g, we have: 0.0002 mol/g x 1000 g/L = 0.2 mol/L = 2.0 m.)

Answer:c) It holds true for both ideal and non-ideal solutions. (Raoult’s law is valid for both ideal and non-ideal solutions, where the non-ideality of the solution is accounted for by introducing activity coefficients. It is applicable to all concentrations and temperatures.)

Answer:c) ΔTb = Kb m. (The boiling point elevation is directly proportional to the molal concentration of the solute, and the proportionality constant is known as the molal boiling point elevation constant, Kb. Therefore, ΔTb = Kb m.)

Answer:a) ΔTf = Kf m. (The freezing point depression is directly proportional to the molal concentration of the solute, and the proportionality constant is known as the molal freezing point depression constant, Kf. Therefore, ΔTf = Kf m.)

Answer:b) 1.0 m. (The molecular weight of NaCl is 58.44 g/mol. Therefore, the number of moles of NaCl present in the solution is: 29.22 g / 58.44 g/mol = 0.5 mol. The mass of water present in the solution is: 500 mL x 1 g/mL = 500 g. Therefore, the molality of the solution is: (0.5 mol / 500 g) x 1000 g/kg = 1.0 m.)

Answer:c) 0.105. (The mole fraction of water vapor in the mixture is given by: mole fraction = (partial pressure of water vapor) / (total pressure of the mixture). Therefore, mole fraction = 20 torr / 760 torr = 0.026. Alternatively, we can use the fact that the mole fraction of water vapor is equal to the ratio of the vapor pressure of water at the given temperature to the total pressure of the mixture. At 25°C, the vapor pressure of water is 23.76 torr. Therefore, mole fraction = 23.76 torr / 760 torr = 0.105.)

Answer:d) 0.050. (The vapor pressure of the solution is related to the mole fraction of the solute by Raoult’s law: vapor pressure of solution = mole fraction of solvent x vapor pressure of pure solvent. Therefore, the mole fraction of glucose in the solution is given by: mole fraction of glucose = (vapor pressure of solution) / (vapor pressure of pure water) = 22.50 mm Hg / 23.76 mm Hg = 0.947. The mole fraction of water in the solution is then 1 – 0.947 = 0.053. Since there is only one solute present, the mole fraction of glucose is 0.053 x 10 g / (180.16 g/mol) = 0.029. Therefore, the mole fraction of glucose in the solution is 0.029 / (0.029 + 0.053) = 0.050.)

Answer:c) The heat of mixing is always negative. (In an ideal solution, the intermolecular forces between the components are similar to those between the molecules of each component, the vapor pressure of the solution follows Raoult’s law, and the osmotic pressure of the solution follows van’t Hoff’s law. However, the heat of mixing is always negative, indicating that energy is released when the components are mixed.)

Answer: Answer: c) The heat of mixing can be either positive or negative. (In a non-ideal solution, the intermolecular forces between the components are different from those between the molecules of each component, and the vapor pressure and osmotic pressure of the solution do not follow Raoult’s and van’t Hoff’s laws, respectively. The heat of mixing can be either positive or negative, depending on the nature of the intermolecular forces and the size and shape of the molecules.)

Answer:a) Boiling point elevation. (Colligative properties are properties of a solution that depend only on the number of solute particles present, and not on their nature or identity. Boiling point elevation, freezing point depression, vapor pressure lowering, and osmotic pressure are examples of colligative properties.)

Answer:a) The vapor pressure of the solution is higher than that of the pure solvent. (In a dilute solution, the number of solute particles is small compared to the number of solvent molecules, so the vapor pressure of the solution is higher than that of the pure solvent.)

Answer:c) The boiling point elevation of the solution is higher than that of a dilute solution. (In a concentrated solution, the number of solute particles is large compared to the number of solvent molecules

Answer:a) The vapor pressure of the solution is always higher than that of the pure solvent. (Raoult’s law states that the vapor pressure of a solution is proportional to the mole fraction of the solvent in the solution. Therefore, if the solution obeys Raoult’s law, its vapor pressure will always be higher than that of the pure solvent.)

Answer:c) The boiling point of the solution is always higher than that predicted by Raoult’s law. (A positive deviation from Raoult’s law means that the vapor pressure of the solution is higher than that predicted by Raoult’s law, indicating that the intermolecular forces between the components are stronger than those between the molecules of each component. This results in a higher boiling point than predicted by Raoult’s law.)

Answer:b) The vapor pressure of the solution is always lower than that predicted by Raoult’s law. (A negative deviation from Raoult’s law means that the vapor pressure of the solution is lower than that predicted by Raoult’s law, indicating that the intermolecular forces between the components are stronger than those between the molecules of each component. This results in a lower vapor pressure than predicted by Raoult’s law.).

Answer:b) The vapor pressure of the solution follows Raoult’s law. (In an ideal solution, the intermolecular forces between the components are similar to those between the molecules of each component, and the vapor pressure of the solution follows Raoult’s law.)