A reaction has two reactants and two products.

Which type of reaction does not fit the descriptive statement?
Select all that apply.
A. Double-displacement
B. Single-displacement
C. Synthesis
D. Decomposition
E. Combustion
C & D right?

I agree.

Synthesis is 2Na + O2 ==>2Na2O2
Decomposition is Na2CO3 ==> Na2O + CO2
Neither meets the criteria in the problem.

I'm glad at least DrBob is still around.

To determine which type(s) of reaction do not fit the descriptive statement, we need to understand the characteristics of each reaction type and see if any of them differ from the given statement.

A. Double-displacement reaction: In this type of reaction, the positive ions of two different compounds switch places, forming two new compounds. This reaction involves two reactants and two products, so it fits the descriptive statement.

B. Single-displacement reaction: In this type of reaction, an element reacts with a compound, displacing another element from it. This reaction involves one reactant and one product, so it does not fit the descriptive statement.

C. Synthesis reaction: In this type of reaction, two or more substances combine to form a new compound. This reaction involves multiple reactants and one product, so it does not fit the descriptive statement.

D. Decomposition reaction: In this type of reaction, a compound breaks down into two or more simpler substances. This reaction involves one reactant and multiple products, so it does not fit the descriptive statement.

E. Combustion reaction: In this type of reaction, a substance reacts with oxygen, usually producing heat and light. This reaction often involves one reactant and multiple products, so it does not fit the descriptive statement.

Based on the explanations above, the types of reactions that do not fit the descriptive statement are B (Single-displacement), C (Synthesis), D (Decomposition), and E (Combustion).