1.24 g of AX2 (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 AY2 (molar mass 250 g mol–1) in 2 kg of water constitutes a so

Question

1.24 g of AX2 (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 AY2 (molar mass 250 g mol–1) in 2 kg of water constitutes a solution with a boiling point of 100.0260°C. Kb(H2O) = 0.52 K kg mol–1 Which of the following is correct?

(A) AX2 is completely unionised while AY2 is fully ionised.
(B) AX2 and AY2 (both) are completely unionised.
(C) AX2 is fully ionised while AY2 is completely unionised.
(D) AX2 and AY2 (both) are fully ionised.

Prashant Kotian · Accepted Answer

Correct answer: C. For solution of AX2 in water Molarity = 10–2 (Tb)obs = 0.0156 (DTf)obs = i × Kb × molarity 0.0156 = i × 0.52 × 10–2 i = 3 Hence AX2 is 100% ionised. For solution of AY2 in water Molarity = 250 / . = 0.0508 (Tb)obs = 0.0260 = i ×Kb × molarity . 52 . 0260 .  = i = 1 completely unionised

💡 Solution & Explanation

Practice 22,000+ questions like this