Final answer:
In a double replacement reaction between compounds A and B, the major product named C is formed by the "switching partners" of cations and anions, leading to a synthesis reaction if one product is formed from two reactants.
Step-by-step explanation:
The question pertains to a substitution reaction where the major product needs to be determined. This is typically a part of an organic chemistry topic that high school or college students would encounter. To solve this problem, one must consider the molecular structure of the reactants and predict the outcome of the reaction. In a double replacement reaction, the cations and anions from the reacting compounds typically "switch partners". For example, if compound A is AC and compound B is BD, the reaction would produce AD and BC, assuming AB is not formed due to reactivity issues.
A correct response would require a visual description or drawing of the major product formed in the reaction between A and B, but since we're limited in text format here, a representation in words will be used. The product named C would be a result of cations A and C pairing with anions B and D, as appropriate based on charge balance and the solubility rules.
This reaction is a synthesis reaction if two reactants combine to form one product. For instance, if A and B combine to form AB, it is a synthesis reaction. On the other hand, the reaction would be a decomposition reaction if one reactant breaks down into two or more products. In this context, since we are talking about a substitution reaction leading to a product C, we might be dealing with a synthesis process, particularly if C is being formed from a combination of elements from A and B.