Question

Write the balanced formula, complete ionic, and net ionic equations for each of the following acid–base reactions. a. \(\mathrm{HNO}_{3}(a q)+\mathrm{Al}(\mathrm{OH})_{3}(s) \rightarrow\) b. \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q)+\mathrm{KOH}(a q) \rightarrow\) c. \(\mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HCl}(a q) \rightarrow\)

Short answer

a. Balanced formula equation: \[3\mathrm{HNO}_{3}(a q)+\mathrm{Al}(\mathrm{OH})_{3}(s) \rightarrow \mathrm{Al(NO}_{3})_{3}(a q) + 3\mathrm{H}_{2}\mathrm{O}(l)\] Net ionic equation: \[3\mathrm{H^{+}}(a q) + 3\mathrm{OH}^{-}(a q) \rightarrow 3\mathrm{H}_{2}\mathrm{O}(l)\] b. Balanced formula equation: \[\mathrm{HC}_{2}\mathrm{H}_{3}\mathrm{O}_{2}(a q)+\mathrm{KOH}(a q)\rightarrow\mathrm{KC}_{2}\mathrm{H}_{3}\mathrm{O}_{2}(a q)+\mathrm{H}_{2}\mathrm{O}(l)\] Net ionic equation: \[\mathrm{H^{+}}(a q) + \mathrm{OH}^{-}(a q) \rightarrow \mathrm{H}_{2}\mathrm{O}(l)\] c. Balanced formula equation: \[\mathrm{Ca}(\mathrm{OH})_{2}(a q)+2\mathrm{HCl}(a q) \rightarrow \mathrm{CaCl}_{2}(a q) + 2\mathrm{H}_{2}\mathrm{O}(l)\] Net ionic equation: \[2\mathrm{H^{+}}(a q) + 2\mathrm{OH}^{-}(a q) \rightarrow 2\mathrm{H}_{2}\mathrm{O}(l)\]

Step-by-step solution

In this reaction, \(\mathrm{HNO}_{3}\) is the acid and \(\mathrm{Al(OH)}_{3}\) is the base. When they react, they will form a salt (aluminium nitrate) and water. #Step 2: Write the balanced formula equation#

The balanced formula equation for this reaction is: \[3\mathrm{HNO}_{3}(a q)+\mathrm{Al}(\mathrm{OH})_{3}(s) \rightarrow \mathrm{Al(NO}_{3})_{3}(a q) + 3\mathrm{H}_{2}\mathrm{O}(l)\] #Step 3: Write the complete ionic equation#

The complete ionic equation for this reaction is: \[3\mathrm{H^{+}}(a q) + 3\mathrm{NO}_{3}^{-}(a q) + \mathrm{Al^{3+}}(a q) + 3\mathrm{OH}^{-}(a q) \rightarrow \mathrm{Al^{3+}}(a q) + 3\mathrm{NO}_{3}^{-}(a q) + 3\mathrm{H}_{2}\mathrm{O}(l)\] #Step 4: Write the net ionic equation#

The net ionic equation for this reaction is: \[3\mathrm{H^{+}}(a q) + 3\mathrm{OH}^{-}(a q) \rightarrow 3\mathrm{H}_{2}\mathrm{O}(l)\] # For Reaction (b) # #Step 1: Identify reactants and products#

In this reaction, \(\mathrm{HC}_{2}\mathrm{H}_{3}\mathrm{O}_{2}\) (acetic acid) is the acid and \(\mathrm{KOH}\) is the base. When they react, they will form a salt (potassium acetate) and water. #Step 2: Write the balanced formula equation#

The balanced formula equation for this reaction is: \[\mathrm{HC}_{2}\mathrm{H}_{3}\mathrm{O}_{2}(a q)+\mathrm{KOH}(a q)\rightarrow\mathrm{KC}_{2}\mathrm{H}_{3}\mathrm{O}_{2}(a q)+\mathrm{H}_{2}\mathrm{O}(l)\] #Step 3: Write the complete ionic equation#

The complete ionic equation for this reaction is: \[\mathrm{H^{+}}(a q) + \mathrm{C}_{2}\mathrm{H}_{3}\mathrm{O}_{2}^{-}(a q) + \mathrm{K}^{+}(a q) + \mathrm{OH}^{-}(a q) \rightarrow \mathrm{K}^{+}(a q) + \mathrm{C}_{2}\mathrm{H}_{3}\mathrm{O}_{2}^{-}(a q) + \mathrm{H}_{2}\mathrm{O}(l)\] #Step 4: Write the net ionic equation#

The net ionic equation for this reaction is: \[\mathrm{H^{+}}(a q) + \mathrm{OH}^{-}(a q) \rightarrow \mathrm{H}_{2}\mathrm{O}(l)\] # For Reaction (c) # #Step 1: Identify reactants and products#

In this reaction, \(\mathrm{Ca(OH)}_{2}\) is the base and \(\mathrm{HCl}\) is the acid. When they react, they will form a salt (calcium chloride) and water. #Step 2: Write the balanced formula equation#

The balanced formula equation for this reaction is: \[\mathrm{Ca}(\mathrm{OH})_{2}(a q)+2\mathrm{HCl}(a q) \rightarrow \mathrm{CaCl}_{2}(a q) + 2\mathrm{H}_{2}\mathrm{O}(l)\] #Step 3: Write the complete ionic equation#

The complete ionic equation for this reaction is: \[\mathrm{Ca^{2+}}(a q) + 2\mathrm{OH}^{-}(a q) + 2\mathrm{H^{+}}(a q) + 2\mathrm{Cl}^{-}(a q) \rightarrow \mathrm{Ca^{2+}}(a q) + 2\mathrm{Cl}^{-}(a q) + 2\mathrm{H}_{2}\mathrm{O}(l)\] #Step 4: Write the net ionic equation#

The net ionic equation for this reaction is: \[2\mathrm{H^{+}}(a q) + 2\mathrm{OH}^{-}(a q) \rightarrow 2\mathrm{H}_{2}\mathrm{O}(l)\]

Key concepts

Balanced Chemical Equations

A balanced chemical equation represents the reactants and products in a chemical reaction with proper stoichiometric coefficients. It ensures that the number of atoms for each element is the same on both sides of the equation, following the Law of Conservation of Mass. For an acid-base reaction, balancing is crucial since it helps us understand the exact ratio of acids to bases involved, determining how much product will be formed.
The process involves identifying the reactants (acids and bases) and products (salts and water). For instance, in the reaction between nitric acid (\(\mathrm{HNO}_3\)) and aluminum hydroxide (\(\mathrm{Al(OH)}_3\)), the balanced equation is:\[3\mathrm{HNO}_3(aq) + \mathrm{Al(OH)}_3(s) \rightarrow \mathrm{Al(NO}_3)_3(aq) + 3\mathrm{H}_2\mathrm{O}(l)\]This shows that three molecules of nitric acid react with one formula unit of aluminum hydroxide to produce one formula unit of aluminum nitrate and three molecules of water. This step ensures that chemical equations are accurately representative of what happens during the reaction.

Complete Ionic Equations

Complete ionic equations break down aqueous compounds into their respective ions, providing a clearer picture of the species that are present in solution during the reaction. They are particularly useful in acid-base reactions, as they showcase how ions interact to form products.
For example, when analyzing the complete ionic equation for the reaction between acetic acid (\(\mathrm{HC}_2\mathrm{H}_3\mathrm{O}_2\)) and potassium hydroxide (\(\mathrm{KOH}\)), we separate the compounds into their ions:

• Acetic acid contributes \(\mathrm{H}^+\) and \(\mathrm{C}_2\mathrm{H}_3\mathrm{O}_2^-\)
• Potassium hydroxide contributes \(\mathrm{K}^+\) and \(\mathrm{OH}^-\)
• The complete ionic equation would then be:

\[\mathrm{H}^+(aq) + \mathrm{C}_2\mathrm{H}_3\mathrm{O}_2^-(aq) + \mathrm{K}^+(aq) + \mathrm{OH}^-(aq) \rightarrow \mathrm{K}^+(aq) + \mathrm{C}_2\mathrm{H}_3\mathrm{O}_2^-(aq) + \mathrm{H}_2\mathrm{O}(l)\]Complete ionic equations allow us to see which ions are actively participating in the reaction and which remain unchanged, often referred to as spectator ions.

Net Ionic Equations

Net ionic equations simplify the reaction by removing the spectator ions, illustrating only the ions and molecules directly involved in the chemical transformation. This form of an equation highlights the essence of the acid-base interaction.
In the case of the reaction between calcium hydroxide (\(\mathrm{Ca(OH)}_2\)) and hydrochloric acid (\(\mathrm{HCl}\)), the net ionic equation focuses solely on the ions that form water, which is the essence of the acid-base neutralization:\[2\mathrm{H}^+(aq) + 2\mathrm{OH}^-(aq) \rightarrow 2\mathrm{H}_2\mathrm{O}(l)\]Notice that calcium ions (\(\mathrm{Ca^{2+}}\)) and chloride ions (\(\mathrm{Cl^-}\)) are not part of the net ionic equation because they don't change and exist in the same form on both the reactant and product sides. By focusing on the reacting species, net ionic equations provide a clearer and more concise representation of the chemical processes occurring in the reaction.