Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AIIMS2006ChemistrySolutions

Assertion : The water pouch of instant cold pack for treating athletic injuries breaks when squeezed and NH ₄ NO ₃ dissolves lowering the temperature. Reason : Addition of non-volatile solute into solvent results into depression of freezing point of solvent.

Options

  1. AIf both assertion and reason are true and reason is the correct explanation of the assertion
  2. BIf both assertion and reason are true but reason is not the correct explanation of the assertion
  3. CIf assertion is true, but reason is false
  4. DBoth assertion and reason are false statements.

Correct answer

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

Step-by-step solution

Freezing point of a substance is defined as the temperature at which the vapour pressure of its liquid is equal to the vapour pressure of the corresponding solid. Since the addition of a non-volatile solute always lowers the vapour pressure of solvent, therefore it will be in equilibrium with solid phase at a lower pressure and hence at a lower temperature.

Practice Solutions on Quantrex Academy →

More from Solutions

What is boiling point of solution containing 7.45 g of KCl in 500 g of water, assuming 80 % dissociation of KCl ? (molar mass of KCl = 74.5 g/mole , k_b for water = 0.52 K/molal ) 2026Identify from the following pair of solutions on mixing exhibits positive deviation from Raoult's law. 2026A solution containing 1.2 g nonvolatile solute in 100 g. of a solvent has a boiling point elevation 1.2 K. Calculate the molar mass of solute if molal elevation constant of solvent 2026The osmotic pressure of barium chloride and glucose solution of the same concentration at the same temperature are respectively 0.62 atm and 0.24 atm. Calculate the van't Hoff fact 2026Which of the following aqueous solutions exhibits maximum freezing point depression assuming complete dissociation? 2026A solution contains 50 g of common salt in 500 gm of water. Find the concentration of the solution in terms of percentage. 2026What should be the molarity of aqueous solution of K ₂ SO ₄ so that it is isotonic with aqueous 1 M glucose at same temperature, assuming complete dissociation? 2026Which of the following solutions has maximum vapour pressure? 2026 Full Solutions list All AIIMS PYQs