Question

Complete the following neutralization reactions. Balance each reaction, and then write the overall ionic and net ionic equation for each. $$ \begin{array}{l}{\text { a. } \mathrm{HCl}(a q)+\mathrm{NaOH}(a q) \longrightarrow} \\ {\text { b. } \mathrm{HNO}_{3}(a q)+\mathrm{KOH}(a q) \longrightarrow} \\ {\text { c. } \mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HNO}_{3}(a q) \longrightarrow} \\ {\text { d. } \mathrm{Mg}(\mathrm{OH})_{2}(a q)+\mathrm{HCl}(a q) \longrightarrow}\end{array} $$

Short answer

The balanced neutralization reactions are: a. HCl + NaOH -> H2O + NaCl; b. HNO3 + KOH -> H2O + KNO3; c. Ca(OH)2 + 2HNO3 -> 2H2O + Ca(NO3)2; d. Mg(OH)2 + 2HCl -> 2H2O + MgCl2. The net ionic equation for all is: H⁺ + OH⁻ -> H2O.

Step-by-step solution

Title - Identify the Products of the Reactions

Neutralization reactions typically produce water and a salt. For each given reactant pair, determine the products: (a) HCl + NaOH -> H2O + NaCl (b) HNO3 + KOH -> H2O + KNO3 (c) Ca(OH)2 + HNO3 -> H2O + Ca(NO3)2 (d) Mg(OH)2 + HCl -> H2O + MgCl2

Title - Balance the Reactions

Balance each reaction: (a) HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq) (b) HNO3(aq) + KOH(aq) -> H2O(l) + KNO3(aq) (c) Ca(OH)2(aq) + 2HNO3(aq) -> 2H2O(l) + Ca(NO3)2(aq) (d) Mg(OH)2(aq) + 2HCl(aq) -> 2H2O(l) + MgCl2(aq)

Title - Write the Full Ionic Equations

Dissociate all strong electrolytes: (a) H⁺(aq) + Cl⁻(aq) + Na⁺(aq) + OH⁻(aq) -> H2O(l) + Na⁺(aq) + Cl⁻(aq) (b) H⁺(aq) + NO3⁻(aq) + K⁺(aq) + OH⁻(aq) -> H2O(l) + K⁺(aq) + NO3⁻(aq) (c) Ca²⁺(aq) + 2OH⁻(aq) + 2H⁺(aq) + 2NO3⁻(aq) -> 2H2O(l) + Ca²⁺(aq) + 2NO3⁻(aq) (d) Mg²⁺(aq) + 2OH⁻(aq) + 2H⁺(aq) + 2Cl⁻(aq) -> 2H2O(l) + Mg²⁺(aq) + 2Cl⁻(aq)

Title - Write the Net Ionic Equations

Cancel out the spectator ions: (a) H⁺(aq) + OH⁻(aq) -> H2O(l) (b) H⁺(aq) + OH⁻(aq) -> H2O(l) (c) 2H⁺(aq) + 2OH⁻(aq) -> 2H2O(l) (d) 2H⁺(aq) + 2OH⁻(aq) -> 2H2O(l)

Key concepts

ionic equations

Ionic equations are a way to show the details of a chemical reaction. They specifically display which ions are present in the solution. In neutralization reactions, acids and bases dissociate into their respective ions when dissolved in water. For instance, when HCl and NaOH react, they dissociate into their ions as follows:
HCl(aq) -> H⁺(aq) + Cl⁻(aq) and NaOH(aq) -> Na⁺(aq) + OH⁻(aq).
The products, NaCl and H₂O, can also be expressed in ionic form, where water remains as a molecule, and sodium chloride dissociates into its ions: NaCl(aq) -> Na⁺(aq) + Cl⁻(aq).
This results in a full ionic equation that indicates all ions involved in the reaction.

net ionic equations

Net ionic equations help us focus on the actual chemical change without interference from spectator ions. Spectator ions appear on both sides of a complete ionic equation but do not participate in the reaction. To write the net ionic equation, first, write the overall ionic equation. For example, in the reaction between HCl and NaOH:
H⁺(aq) + Cl⁻(aq) + Na⁺(aq) + OH⁻(aq) -> H₂O(l) + Na⁺(aq) + Cl⁻(aq).
Here, Na⁺ and Cl⁻ are spectator ions. By removing these spectator ions, we get the net ionic equation:
H⁺(aq) + OH⁻(aq) -> H₂O(l).
This focuses on the actual reaction happening in the solution.

balancing chemical reactions

Balancing chemical reactions ensures that the same number of atoms of each element is present on both the reactant and product sides of the equation. This follows the Law of Conservation of Mass. To balance a reaction, adjust the coefficients of the reactants and products. For example, the reaction between Ca(OH)₂ and HNO₃:
Ca(OH)₂ + 2HNO₃ -> 2H₂O + Ca(NO₃)₂.
Each side of the balanced equation has:
- 1 calcium (Ca)
- 2 nitrogen (N)
- 6 oxygen (O)
- 4 hydrogen (H).
This balance ensures that matter is conserved in the reaction.

products of reactions

Products of neutralization reactions generally include water and a salt. The specific products depend on the acid and base that react. For instance:
- HCl + NaOH -> H₂O + NaCl
- HNO₃ + KOH -> H₂O + KNO₃
- Ca(OH)₂ + HNO₃ -> H₂O + Ca(NO₃)₂
- Mg(OH)₂ + HCl -> H₂O + MgCl₂.
The salt formed is a compound consisting of the cation from the base and the anion from the acid. Water is produced from the hydrogen ion of the acid combining with the hydroxide ion of the base. Knowing the products can help in predicting the outcome of chemical reactions.