JEE Main202529 Jan 2025Morning ShiftChemistrySolutionsActual
1.24 g of ( AX ₂ ) (molar mass (124 ~g ~mol ⁻¹ ) ) is dissolved in 1 kg of water to form a solution with boiling point of (100.0156^ C ), while (25.4 ~g ^ ) of ( AY ₂ ) (molar mass (250 ~g ~mol ⁻¹ ) ) in 2 kg of water constitutes a solution with a boiling point of (100.0260^ C ). ( K _ b ( H ₂ O )=0.52 ~K ~kg ~mol ⁻¹ ) Which of the following is correct ?
Options
- A( AX ₂ ) is fully ionised while ( AY ₂ ) is completely unionised.
- B( AX ₂ ) is completely unionised while ( AY ₂ ) is fully ionised.
- C( AX ₂ ) and ( AY ₂ ) (both) are completely unionised.
- D( AX ₂ ) and ( AY ₂ ) (both) are fully ionised.
Correct answer
A. ( AX ₂ ) is fully ionised while ( AY ₂ ) is completely unionised.
Step-by-step solution
For AX ₂ aligned & T _ b = i ~K ~m & 0.0156= i 0.52 1.24 124 1 & 3= i & 3=1+2 & 1= aligned For AY ₂ aligned & T _ b = i ~K _ b ~m & 0.0260= i 0.52 25.4 250 2 & i 1 aligned A X₂ is completely ionised & A Y₂ is completely unionised