Search results
Results from the WOW.Com Content Network
Salt metathesis is often employed to obtain salts that are soluble in organic solvents. Illustrative is the conversion of sodium perrhenate to the tetrabutylammonium salt: [2] NaReO 4 + N(C 4 H 9) 4 Cl → N(C 4 H 9) 4 [ReO 4] + NaCl. The tetrabutylammonium salt precipitates from the aqueous solution. It is soluble in dichloromethane.
Metathesis reactions are another term for double-displacement; that is, when a cation displaces to form an ionic bond with the other anion. The cation bonded with the latter anion will dissociate and bond with the other anion. [1] A common metathesis reaction in aqueous solutions is a precipitation reaction.
The salt metathesis reaction results in precipitation of solid calcium carbonate, leaving potassium hydroxide in solution: Ca(OH) 2 + K 2 CO 3 → CaCO 3 + 2 KOH. Filtering off the precipitated calcium carbonate and boiling down the solution gives potassium hydroxide ("calcinated or caustic potash").
Tetraethylammonium hydroxide is most commonly encountered as an aqueous solution. Several hydrates NEt 4 OH·xH 2 O. have been crystallized, including x = 4, 5, 9. These salts feature well separated Et 4 N + cations and hydroxide anions. The hydroxide groups are linked by hydrogen bonds to the water of crystallization. Anhydrous ...
The manganese dithionate solution formed can then be converted to dithionate salts of other metals by metathesis reactions: Ba 2+ (aq) + MnS 2 O 6 (aq) + MnSO 4 (aq) → BaSO 4 (s)↓ + BaS 2 O 6 · 2 H 2 O (aq) Concentrated solutions of dithionic acid can subsequently be obtained treating a barium dithionate solution with sulfuric acid:
Solutions of TMAH may be used to make other tetramethylammonium salts in metathesis reactions with ammonium (NH 4 +) salts. For example, tetramethylammonium thiocyanate may be prepared from ammonium thiocyanate as follows: [7] NMe 4 + OH − + NH 4 + SCN − → NMe 4 + SCN − + NH 3 + H 2 O
Potassium chlorate can be produced in small amounts by disproportionation in a sodium hypochlorite solution followed by metathesis reaction with potassium chloride: [7] 3 NaOCl → 2 NaCl + NaClO 3 KCl + NaClO 3 → NaCl + KClO 3. It can also be produced by passing chlorine gas into a hot solution of caustic potash: [8] 3 Cl 2 + 6 KOH → KClO ...
Lithium hydroxide is often produced industrially from lithium carbonate in a metathesis reaction with calcium hydroxide: [7] Li 2 CO 3 + Ca(OH) 2 → 2 LiOH + CaCO 3. The initially produced hydrate is dehydrated by heating under vacuum up to 180 °C.