Answer:
double-displacement
Step-by-step explanation:
Na2S (aq) + Cd(NO3)2(aq) → CdS (s) + 2NaNO3(aq)
Let's look at the meaning f the various options before answering the question.
Single Displacement Reaction: A single-displacement reaction, is a chemical reaction in which one element replaces an/other element in a compound. It can be represented generically as: A + B-C → A-C + B
Double Displacement Reaction: A double-replacement reaction occurs when parts of two ionic compounds are exchanged, making two new compounds. A characteristic of a double-replacement equation is that there are two compounds as reactants and two different compounds as products. This is represented as AB + CD --> BC + AD
Decompostion Reaction: The chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction. This is represented as; A --> B + C
synthesis reaction or direct combination reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex product. The reactants may be elements or compounds, while the product is always a compound. This is represented as; A + B --> C
Among all the reactions, the reaction fits the criteria of the double displacement reaction. Hence the correct option is double displacement.