AP Reaction Set Quickie Notes
1. Know all of the solubility rules – especially the exceptions!!!
2. Try to ID the type of reaction first – then think about the rules that apply to that type of Rxn.
3. All nitrates are soluble so drop it (one exception: copper in nitric acid – the nitrate goes to NO (if acid is dilute) or to NO2 (if acid is concentrated).
4. Group 1 metals are all soluble so if they are already in solution on the left, drop them
5. No ions unless a solution!
6. Synthesis: element + element makes a compound – watch diatomics!
7. Synthesis: compound + compound happens usually with a metal oxide and nonmetal oxide
– they make a salt
8. Metal oxide is a basic anhydride – nonmetal oxide is an acidic anhydride, so when you put each in water separately, the metal oxide makes base, the nonmetal oxide an acid
9. Strong acids and bases - write separately; weak acids and bases stay together
10. Group 1 metals in water – strong base and H2 gas
11. Group 2 metals in water – strong base and H2 gas for the more reactive ones (look for heated solution to help production of H2)
12. Decomposition: easy – look for heating of a salt, two compounds formed - usually oxides (generally never the metal by itself)
- watch for chlorates – decompose to metal chloride plus water
13. Electrolysis – (other type of decomposition) compound breaks into elements ; if aqueous solution, water can be either oxidized or reduced
14. Combustion: some hydrocarbon (or alcohol) plus O2 (even if it says air, put O2) – must have heat/burn - produces water and CO2 (watch for N2 - mostly same but with N instead of C) – even if you don’t know the formula of the hydrocarbon you can still get points for putting the CO2 and water
15. Single replacements: are technically redox but – element plus compound so the element goes into the new compound and one of the species of the compound becomes the element – look for a halogen (diatomic) plus a compound with a halogen (the “new” halogen also becomes diatomic – remember, not diatomic while in compound – also, metal plus compound etc.
16. Double replacements: usually two salt solutions where you get a precipitate – know colors!, sometimes you have two precipitates but rare – don’t forget to drop the spectator ions
17. Weak stuff, watch these – remember equilibrium, and the moving of the H, watch polyprotic acids, watch the molarity to determine how many H’s come off
18. Redox – watch for terms “acidified or alkaline”, Cr (esp. chromate & dichromate), Fe, Mn, halogens, SO2, NO31- & HNO2, H2O2 (acts as both oxiziding & reducing agent), disproportionation (one element doing both – generally the halogens but have seen the others do it to
19. Complexes – watch for ammonia (but don’t confuse with a weak base question), silver, copper, iron, aluminum, zinc, cobalt – generally the charge and subscript add up to “6” – never more than 6, but for reaction complexes, the coordination number is most commonly “4”. Know names of ligands.
20.Pay special attention to complexes of Al & Zn - Zn(OH)2 dissolves in aq. NH3 – Al(OH)3 doesn’t
21. Memorize the common polyatomic ions! and the oxidation states of common metals!
22. If the word “solution” describes the substance (ex. a solution of sodium carbonate) then write “it” separately in ion form (ie. only use the carbonate ion)– but only if it is an ionic compound (molecules like H2O2 stay together)
– but if it says gas or solid or metal you write the entire compound (ex. solid sodium carbonate)
23.Do NOT write the state of matter in the equation – if you write it incorrectly, it will lose you points.
24. Aqueous ammonia – can be used for hydroxide ion, ammonia gas, or ammonium ion.