Assertion : Addition of NH₄OH to an aqueous solution of BaCl₂ in the presence of NH₄Cl (excess) precipitates Ba(OH)₂.

Reason : Ba(OH)₂ is insoluble in water.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : The molecular weight of acetic acid determined by depression in freezing point method in benzene and water was found to be different.

Reason : Water is polar and benzene is non-polar.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Which one of these, is not a colligative property ?

• vapour pressure

• osmotic pressure

• lowering in freezing point

• Elevation in boiling point

The osmotic pressure of which solution is maximum? (consider that decimormal solution of each is 90% dissociated) :

• Aluminium sulphate

• Barium chloride

• Sodium sulphate

• A mixture of equal volumes of (b) and (c)

The mixture ofconcentrated HCl and HNO₃ made in 3 : 1 ratio contains

• ClO₂

• NOCl

• NCl₃

• N₂O₄

The average osmotic pressure of human blood is 7.8 bar at 37°C. What is the concentration of an aqueous NaCl solution that could be used in the blood stream?

• 0.16 mol/L

• 0.32 mol/L

• 0.60 mol/L

• 0.45 mol/L

Which one of the statements given below concerning properties of solutions, describes a colligative effect?

• Boiling point of pure water decreases by the addition of ethanol.

• Vapour pressure of pure water decreases by the addition of nitric acid.

• Vapour pressure of pure benzene decreases by the addition of naphthalene.

• Boiling point of pure benzene increases by the addition of toluene.

Which one of the following is not a buffer solution?

• 0.8M H₂S + 0.8M KHS

• 2M C₆H₅NH₂ + 2M C₆H₅NH₃^-Br^-

• 3M H₂CO₃ + 3M KHCO₃

• 0.05M KClO₄ + 0.05M HClO₄

In aqueous alkaline solution, two electrons reduction of HO${}_2^{-}$ gives

• HO^-

• H₂O

• O₂

• ${\mathrm{O}}_2^{-}$

Vapour pressure of benzene at 30°C is 121.8 mm. When 15 g of a non-volatile solute is dissolved in 250 g of benzene, its vapour pressure is decreased to 120.2 mm. The molecular weight of the solute is

• 35.67 g

• 356.7 g

• 432.8 g

• 502. 7 g