Chemical Reactions

blue fire   =   copper sulfate+ chlorine donor+fire
copper sulfate is available as septic tank root killer treatment.  Used alone will produce a pretty green flame.
Not as brilliant a green as the boric acid but pretty none the less.

A chlorine donor may be PVC plastic or ferric chloride.  A similar campfire color demonstration is done with a copper pipe inside a segment old old vinyl garden hose.  The hose provides the chlorine.
PVC plastic is often used as a chlorine donor to produce blue flame effects in fireworks.
 
calcium carbonate   =   calcium hydroxide (in solution) + carbon dioxide
many alkaline earth/metal hydroxides absorb CO2 from the air.
Used in diving "rebreathers" submarines and space shuttle to "scrub" air.

 
calcium hydroxide   =   calcium oxide + water
"slaked" lime
 
Calcium oxide   =   calcium carbonate + intense heat
quicklime  Used to make concrete. 
 
carbon dioxide   =   vinegar + baking soda
acetic acid (3%) and sodium bicarbonate.  Sodium carbonate works too but is caustic and more difficult to find in pure form.
 
green fire   =   boric acis + fire
boric acid is NOT borax (sodium tetraborate) Its actrually the  sodium salt of boric acid.  The sodium will overwhelm any green in the flame.  Use Boric acid
 
hydrogen gas   =   muriatic acid (HCl) + aluminum foil
Generates a lot of heat. HCl and Aluminum Chloride tainted steam/vapor isn't very pleasant
 
hydrogen gas #2   =   strong sodium hydroxide solution + aluminum foil
the lye (sodium hydroxide) acts as a catalyst for the decomposition of water
 
magnesium hydroxide (milk of magnesia)   =   magnesium oxide + water
"gently" alkaline solutions to resolve/neutralize heartburn.  Magnesium is poorly absorbed from the gut and acts as an osmotic laxative.
 
magnesium oxide   =   magnesium + oxygen
A protective layer of magnesium oxide form on magnesium metal exposed to moist air.  Dulls its finish.  Burning magnesium in air gives pure magnesium oxide
 
oxygen   =   household bleach + hydrogen peroxide
The sodium hypochlorite from the bleach and the peroxide react...
 
test   =   test
test
 
Water   =   2 hydrogen, 1 oxygen