Answer:
A) double replacement
Explanation:
Chemical equation:
NaCl +CaS → Na₂S + CaCl₂
Balanced chemical equation:
2NaCl +CaS → Na₂S + CaCl₂
The given reaction is double replacement reaction in which cation and anions of each reactant exchange with each other.
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AD +CB
Other options are incorrect because,
Synthesis reaction:
It is the reaction in which two or more simple substance react to give one or more complex product.
AB → A + B
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
Decomposition reaction:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B
