Solutions Test - 8

Although all the given solutions have the same molarity and all the options are electrolytes yet the number of ions produced in the solution are different in each case.
The van't Hoff factor is the highest (i = 3) for Na₂SO₄ and hence, there is a maximum number of particles of the non-voatile solute in the solution and the change in the colligative property will be the maximum.
Hence, 0.1 M solution of Na₂SO₄ will show the maximum elevation in the boiling point.

Vapour pressure is not a colligative property but relative lowering of the vapour pressure on addition of a non volatile solute is.

At 10 km above the sea level, the atmospheric pressure will be less than that existing at the sea level. Hence, the boiling point of the solution will be less.

Sodium phosphate (Na₃PO₄) is a strong electrolyte and will furnish 4 moles of ions per mole of the salt in its aqueous solution.
Therefore, the van't Hoff factor is the highest for Na₃PO₄ and the depression in the freezing point will be the maximum in the solution of this compound..

Osmosis is the spontaneous net movement of solvent molecules through a semi-permeable membrane into a region of higher solute concentration, in the direction that tends to equalise the solute concentrations on the two sides.

Osmostic pressure, π = i CRT
= (2 x 0.1 mol L^–1)(0.082 atm L K^–1mol^–1)(300 K)
= 4.92 atm