The structure shown is an example of what kind of polymer? a. polyester
b. nylon
c. polyamine
d. polyalkane

Pretty sure it's d. heterogeneous is separated by physical properties. 

If each of the reactants have 2 elements it is usually double displacement. when there is double displacement, if one reactant has hydrogen then it can be acid base. if one reactant has 2 and one has 1, than it is usually single displacement. if there is only one reactant it is decomposition. if there are two reactants that each have one element it is synthesis. if one of the reactants is 02 it can be combustion and the products has to include h20 and c02.

Hope you figure it out: )