Consider the given plots of vapour pressure (VP) vs temperature(T/K). Which amongst the following options is correct graphical representation showing $\Delta \mathrm{T}_{\mathrm{f}}$, depression in the freezing point of a solvent in a solution?

• Correct answer
  A

  
  
• B

  
  
• C

  
  
• D

  
  

Solution

On adding non-volatile solute in a solvent, the freezing point of solution decreases. $\mathrm{T}_{\mathrm{f}} < \mathrm{T}_{\mathrm{f}}^0$ F.P. of solution $ < $ F.P. of pure solvent Also V.P. of solution decreases on adding nonvolatile solute in a solvent.

Hence, the correct answer is option: 'A'.