A mixture initially contains crystalline iodine (I )
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A mixture initially contains crystalline iodine (I2), potassium iodide (KI), and liquid water in a separatory funnel. After the addition of an immiscible layer of hexane (C6H14), the funnel is stoppered and shaken vigorously, then allowed to stand until two clear liquid layers re-form.
(1) Identify the dominant intermolecular attraction between neighboring I2 molecules within the hexane layer once equilibrium is established.
(2) Identify the dominant particle–particle attraction between KI (which dissociates into ions) and water molecules in the aqueous layer.
(3) Explain, on the basis of the interactions named in parts (a) and (b), why the deep purple color of dissolved iodine is observed in the hexane layer rather than in the water layer.
(4) If water were replaced by acetone, (CH3)2CO, predict whether more, less, or approximately the same amount of iodine would be extracted into the organic (non-aqueous) layer. Support your prediction with reference to relevant intermolecular attractions.