AP Eqns (Net Ionics)
Objectives:
Throughout the free response portion of the AP exam you will be expected to apply the solubility rules by writing a net ionic equation and identifing the type of reaction (synthesis, decomposition, double replacement, single replacement, combustion, or REDOX). You may also be expected to answer a short descriptor about the reaction such as (not a comprehensive list):
- identify oxidation states
- color of a substance
- pH based on what occurs in the solution
- mols of products produced
- state of a product
The following are general guidelines when writing a net ionic equation.
Solubility rules
classic Lewis acids and when reacting with ammonia (a classic weak Lewis base), the product is F3BNH3(just smash everything together) since nitrogen
donated its unshared electron pair to boron in an act of extreme generosity and formed a coordinate covalent bond. Lewis Acids Accept an electron pair.
* the little guys in the IIA’s have solubility issues, write Be and Mg UNdissociated—calcium can go either way, the big guys are soluble. HF is not a strong acid since it’s the little guy as well in the halogen series. The little guys make a stronger bond with H and do not dissociate in water. Also remember that the IA
metals are named the alkali metals and the IIA’s are the alkaline earth metals. What does “alkaline” mean? BASIC, so put them in water as metals, they dissolve and you make OH-. Put IA metals in water and KABOOM. KABOOM = formation of explosive hydrogen gas, H2.
Solubility rules
- All nitrates are soluble.
- All IA metals and ammonium salts are soluble.
- Halides: All are soluble except silver, mercury or lead.
- Strong acids: hydrochloric, hydrobromic, hydroiodic, nitric, perchloric, sulfuric—WRITE THESE DISSOCIATED except concentrated sulfuric, it
really is 97% H2SO4 and 3% water in the jug, so water is way outnumbered and the molecules don’t dissociate completely. If
carbonic acid is formed as a product --> CO2 + H2O - Strong bases: hydroxides [and oxides] of IA and IIA* metals—write these bases dissociated.
classic Lewis acids and when reacting with ammonia (a classic weak Lewis base), the product is F3BNH3(just smash everything together) since nitrogen
donated its unshared electron pair to boron in an act of extreme generosity and formed a coordinate covalent bond. Lewis Acids Accept an electron pair.
* the little guys in the IIA’s have solubility issues, write Be and Mg UNdissociated—calcium can go either way, the big guys are soluble. HF is not a strong acid since it’s the little guy as well in the halogen series. The little guys make a stronger bond with H and do not dissociate in water. Also remember that the IA
metals are named the alkali metals and the IIA’s are the alkaline earth metals. What does “alkaline” mean? BASIC, so put them in water as metals, they dissolve and you make OH-. Put IA metals in water and KABOOM. KABOOM = formation of explosive hydrogen gas, H2.