1. COMBINATION REACTIONS: TYPE ONE (of three) group 1A metal + nonmetal → salt salt = cation + anion KCl (s) →Cl 2(g) +K (s) 2 2

2. COMBINATION RXN: TYPE 2 nonmetal oxide + water → acid sulfurous acid H 2 SO 3(aq) →H2O(l)H2O(l) +SO 2(g)

3. COMBINATION RXN: TYPE 3 metal oxide + water → base base: compound that contains hydroxide (OH - ) Ca(OH) 2(aq) →H2O(l)H2O(l) +CaO (s)

4. DOUBLE REPLACEMENT RXN: TYPE 1 ( of three) precipitate formation Na 2 S (aq) + Cd(NO 3 ) 2(aq) → 2 NaNO 3(aq) + CdS (s)

5. DOUBLE REPLACEMENT RXN: TYPE 2 one product is a gas – bubbles out of solution 2 NaCN (aq) + H 2 SO 4(aq) → Na 2 SO 4(aq) + 2 HCN (g)

6. DOUBLE REPLACEMENT RXN: TYPE 3 neutralization: acid + base will produce salt and water Ca(OH) 2(aq) + 2 HCl (aq) → CaCl 2(aq) + 2 H 2 O ( l )

7. DOUBLE REPLACEMENT RXN: TYPE 3A Na 2 CO 3(aq) + H 2 SO 4(aq) → Na 2 SO 4(aq) + H 2 CO 3 falls apart! it becomes H 2 O ( l ) + CO 2(g) ALWAYS happens with a metal carbonate + an acid H 2 CO 3(aq)

8. DOUBLE REPLACEMENT RXN: TYPE 3A Na 2 CO 3(aq) + H 2 SO 4(aq) → Na 2 SO 4(aq) + H 2 O ( l ) + CO 2(g)