NTA Abhyas JEE Main2020ChemistrySolutionsPractice
What is the freezing point of a solution containing 8.1 g HBr in 100 g water, assuming that the acid to be 90% ionized K f H 2 O = 1.86 Kkgmo l - 1 .
Options
- A0.85 ° C
- B+ 3.53 ° C
- C0 ° C
- D- 3.5 ° C
Correct answer
D. - 3.5 ° C
Step-by-step solution
HBr → H + + Br − i = 1 − α +n x n = 2 i = 1 + α ΔΤ g = i kg × m ΔΤ g = 1 − α 1 .86 × 8 .1 81 × 1000 100 ΔΤ g = 1 + 9 × 1 .86 × 8 .1 81 × 10 ΔΤ g = 3 .56 T g o = 0 ° C ΔΤ g = T g o − T g T g = - 3 .534 ° C