Final answer:
The reaction CoCl₂(aq) + 2NaOH(aq) → Co(OH)₂(s) + 2NaCI(aq) is a double-displacement reaction, where the ions in the reactants exchange partners to form new compounds.
The correct answer is option b. double-displacement reaction
Step-by-step explanation:
The reaction represented by the equation CoCl₂(aq) + 2NaOH(aq) → Co(OH)₂(s) + 2NaCI(aq) is a double-displacement reaction. In this type of reaction, the cations and anions of two different compounds switch places, forming two new compounds. The solid Co(OH)₂ which forms in this reaction is a precipitate, indicating that a chemical reaction has occurred. This is a characteristic of most double-displacement reactions.
In comparison, a single-displacement reaction involves one element being replaced by another in a compound. A combustion reaction typically involves a hydrocarbon reacting with oxygen to produce carbon dioxide and water. A synthesis or combination reaction occurs when two or more reactants combine to form a single product. Lastly, a decomposition reaction involves a single compound breaking down into two or more products.