Indicators of a chemical reaction are: :
Indicators of a chemical reaction are: Color change
Energy taken in or released
(reaction gets hot or cold)
Gas is evolved (bubbling or fizzing)
Precipitate is formed
Odor released can be an indicator
Combination Reaction :
Combination Reaction Generic:
A + B C {2 reactants 1 product}
Example:
Solid copper reacts with gaseous oxygen to produce solid copper (II) oxide
2Cu (s) + O2 (g) 2CuO(s)
Decomposition Reaction :
Decomposition Reaction Generic
AB A + B
Example:
Liquid hydrogen peroxide, in the presence of a catalyst, breaks down into liquid water and oxygen gas. (KI acts as a catalyst here.)
KI
2H2O2(l) 2H2O(l) + O2 (g)