I prepared a solution of zncl2 in acetone. It was readily soluble with exothermic reaction. I’m trying to understand chemical reaction behind this. Will the solution be acidic?
And why some other chlorides such as LiCl is not soluble in acetone?
Zn2+ is soft Lewis acid (catalyst), Li+ is hard Lewis acid (catalyst). Acetone C=O is soft. More see
https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Map%3A_Organic_Chemistry_(Smith)/Chapter_20%3A_Introduction_to_Carbonyl_Chemistry%3B_Organometallic_Reagents%3B_Oxidation_and_Reduction/20.02_General_Reactions_of_Carbonyl_Compounds
The carbonyl oxygen of acetone has a noticeably tendency to interact by means of attractive ion–induced dipole force with either the undissociated ZnCl2 or with the dissociated cation, Zn2+, both acting as Lewis acid. Such interaction can slightly displace the keto-enol equilibrium of the acetone solvent to the enol side, despite still largely dominated by the ketone form; while otherwise this last form would be even more preponderant. The enol form is a (weak) Brønsted–Lowry acid, and may possibly donate a proton to dissociated chloride ions, thus possibly generating a small content of dissolved HCl, even if the acetone solvent is truly anhydrous. If the acetone solvent is not dry, even a small water content may play a considerable solvation role, chiefly by favouring salt dissociation and salt cation hydrolysis.
I have discussed the speciation of ZnCl2 in water elsewhere at this forum: https://www.researchgate.net/post/when_i_prepare_a_zinc_chloride_solution_a_white_precipitate_is_shown_plz_can_someone_tell_me_why_and_how_i_can_avoid_this_problem
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