Calculate the molality ( 𝑚 ) of the potassium ion ( K+ ) in a 0.681 𝑚 aqueous solution of K2CO3 . molality of K+ : 𝑚

Answer 1

The dissociation of K₂CO₃:

K₂CO₃ ==> 2K⁺(aq) + CO₃^2-(aq)

Thus, for each mol of K₂CO₃, you get 2 mols of K⁺

0.681 m K₂CO₃ x 2 m K⁺ / 1 m K₂CO₃ = 1.362 m K⁺

(note: this assume a van't Hoff factor of 1 for K₂CO₃)