Complete and balance each equation. If no reaction occurs, write 'NO REACTION.' b. KCl(aq) + CaS(aq) →

Key Concepts

Double Displacement Reaction

A double displacement reaction, also known as a double replacement reaction, occurs when two compounds exchange ions to form two new compounds. In this type of reaction, the cations and anions of the reactants switch partners, which can lead to the formation of a precipitate, gas, or water. Understanding this concept is crucial for predicting the products of the reaction between KCl and CaS.

Solubility Rules

Solubility rules are guidelines that help predict whether a compound will dissolve in water or form a precipitate. For example, most chlorides are soluble, while sulfides are generally insoluble except for those of alkali metals and alkaline earth metals. Applying these rules to the reactants KCl and CaS will help determine if a reaction occurs and what the products will be.

Balancing Chemical Equations

Balancing chemical equations is the process of ensuring that the number of atoms for each element is the same on both sides of the equation. This is based on the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Properly balancing the equation for the reaction between KCl and CaS is essential for accurately representing the reaction and its products.