List of top Chemistry Questions on Solutions asked in UP Board XII

Define Molal depression constant. 48 g of ethylene glycol (C2H6O2) is dissolved in 600 g of water. Calculate (i) depression in freezing point and (ii) freezing point of the solution. [Given Kf(water) = 1.86 °C kg mol-1]
OR
Define molality and explain mole fraction. Calculate the mole fraction of solute and solvent of a 20% aqueous C2H6O2 solution.
0.32 g of a new compound was dissolved in 25 g of water. The freezing point of this solution was found to be \(-0.201\,^\circ\text{C}\). Determine the molecular weight of this new compound. For water \(K_f = 1.86\,^\circ\text{C}\;\text{kg mol}^{-1}\).
Which of the following solutions will have a maximum boiling point?
An aqueous solution of glucose is 10% (w/w). What would be the molality and mole fraction of each component in the solution? (Molar mass of glucose = 180 g mol⁻¹)
Explain reverse osmosis and write any one example of artificial semipermeable membrane. (1+1=2)
Define molal elevation constant. (2)
Read the following assertion and reason and choose the correct alternative.
Assertion: Elevation in boiling point for two isotonic solutions is same.
Reason: Boiling point depends upon the concentration of the solute.
(i) Explain Henry's law. (ii) 200 ml of an aqueous solution of a protein contains 1.26 g of protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 × 10-3 bar. Calculate the molar mass of the protein. (1+2=3)
Aqueous solution of sodium chloride boils at higher temperature than water, but it freezes at lower temperature than water. Explain with reason.
Define molality and molarity.
Read the following assertion and reason and choose the correct alternative.
Assertion: Osmotic pressure is a colligative property.
Reason: Osmotic pressure is directly proportional to molarity at a given temperature.
If 2 g of benzoic acid is dissolved in 25 g of benzene, its depression in freezing point was found to be 1.62 K. Molal depression constant of benzene is 4.9 K kg mol-1. If benzoic acid forms a dimer in this solution, what will be the percentage association of benzoic acid? (5)
OR
A 200 cm3 aqueous solution of a protein contains 1.26 g of protein. The osmotic pressure of this solution at 300 K is \(2.57\times10^{-3}\) bar. Calculate the molar mass of this protein. (5)
A 200 cm3 aqueous solution of a protein contains 1.26 g of protein. The osmotic pressure at 300 K was found to be \(2.57 \times 10^{-3}\) bar. Calculate the molar mass of the protein. (R = 0.083 L bar K-1 mol-1)
State Henry's law and its important applications.
What is an isotonic solution? Explain with an example.
The freezing point decreases by 0.40 K, when 1.00 g non-electrolyte is dissolved in 50 g benzene. The value of \( K_f \) for benzene is 5.12 K kg mol\(^{-1}\). Calculate the molar mass of the solute.
Which of the following is the mathematical form of Raoult's law?
Explain mole fraction. Calculate the mole fraction of ethylene glycol if 20% of the mass of ethylene glycol is present in the solution. [1+4]
OR
i) Calculate the molarity of the solution in which 5 g NaOH is dissolved in 450 mL of solution.
ii) Calculate the molality of the solution in which 2.5 g acetic acid is dissolved in 75 g benzene. [2½+2½]
What is the van't Hoff factor? Write the equation for colligative properties including the van't Hoff factor.
Which of the following is temperature independent?
What is the colligative property? Write an expression for the determination of molar mass of solute using relative lowering in vapour pressure.
45 g ethylene glycol is mixed with 600 g H2O. Calculate the depression of freezing point of this solution. \( (K_f = 1.86\ \text{K kg mol}^{-1}) \)
What is an ideal solution? Mention the characteristics of an ideal solution.
Which formula is used to calculate osmotic pressure?