Problem 52 - Chemistry: An Atoms-Focused Approach

Question

Complete and balance each of the following neutralization reactions, name the products, and write the net ionic equations. a. \(\mathrm{HI}(a q)+\mathrm{LiOH}(a q) \rightarrow\) b. \(\mathrm{H}_{3} \mathrm{PO}_{4}(a q)+\mathrm{KOH}(a q) \rightarrow\) c. \(\mathrm{Al}(\mathrm{OH})_{3}(s)+\mathrm{CH}_{3} \mathrm{COOH}(a q) \rightarrow\) d. \(\mathrm{HNO}_{3}(a q)+\mathrm{Ba}(\mathrm{OH})_{2}(a q) \rightarrow\)

Step-by-Step Solution

Answer

Question: Provide the net ionic equation for each of the following neutralization reactions: a. Hydroiodic acid (HI) reacting with lithium hydroxide (LiOH) b. Phosphoric acid (H3PO4) reacting with potassium hydroxide (KOH) c. Aluminum hydroxide (Al(OH)3) reacting with acetic acid (CH3COOH) d. Nitric acid (HNO3) reacting with barium hydroxide (Ba(OH)2) Answer: a. \(\mathrm{H}^{+}(a q)+\mathrm{OH}^{-}(a q) \rightarrow \mathrm{H}_{2}\mathrm{O}(l)\) b. \(3\mathrm{H}^{+}(a q)+3\mathrm{OH}^{-}(a q) \rightarrow 3\mathrm{H}_{2}\mathrm{O}(l)\) c. \(3\mathrm{H}^{+}(a q)+3\mathrm{OH}^{-}(s) \rightarrow 3\mathrm{H}_{2}\mathrm{O}(l)\) d. \(2\mathrm{H}^{+}(a q)+2\mathrm{OH}^{-}(a q) \rightarrow 2\mathrm{H}_{2}\mathrm{O}(l)\)

Step 1: 1. Identify the products:

In this reaction, hydroiodic acid (HI) reacts with lithium hydroxide (LiOH). A salt is formed between the metal ion (Li) and the non-metal ion (I). So, the products will be lithium iodide (LiI) and water (H2O).

Step 2: 2. Balance the reaction:

The chemical equation is already balanced. The balanced equation is: \(\mathrm{HI}(a q)+\mathrm{LiOH}(a q) \rightarrow \mathrm{LiI}(a q)+\mathrm{H}_{2}\mathrm{O}(l)\)

Step 3: 3. Write the net ionic equation:

In this case, the net ionic equation is: \(\mathrm{H}^{+}(a q)+\mathrm{OH}^{-}(a q) \rightarrow \mathrm{H}_{2}\mathrm{O}(l)\) b. Complete and balance the reaction and find the products:

Step 4: 1. Identify the products:

In this reaction, phosphoric acid (H3PO4) reacts with potassium hydroxide (KOH). A salt is formed between the metal ion (K) and the non-metal ion (PO4). So, the products will be potassium phosphate (K3PO4) and water (H2O).

Step 5: 2. Balance the reaction:

To balance the equation, we need to add 3 KOH on the reactant side and 3 H2O on the product side. The balanced equation is: \(\mathrm{H}_{3} \mathrm{PO}_{4}(a q)+3\mathrm{KOH}(a q) \rightarrow \mathrm{K}_{3} \mathrm{PO}_{4}(a q)+3\mathrm{H}_{2}\mathrm{O}(l)\)

Step 6: 3. Write the net ionic equation:

In this case, the net ionic equation is: \(3\mathrm{H}^{+}(a q)+3\mathrm{OH}^{-}(a q) \rightarrow 3\mathrm{H}_{2}\mathrm{O}(l)\) c. Complete and balance the reaction and find the products:

Step 7: 1. Identify the products:

In this reaction, aluminum hydroxide (Al(OH)3) reacts with acetic acid (CH3COOH). A salt is formed between the metal ion (Al) and the non-metal ion (CH3COO). So, the products will be aluminum acetate (Al(CH3COO)3) and water (H2O).

Step 8: 2. Balance the reaction:

To balance the equation, we need to add 3 CH3COOH on the reactant side and 3 H2O on the product side. The balanced equation is: $\mathrm{Al}(\mathrm{OH})_{3}(s)+3\mathrm{CH}_{3} \mathrm{COOH}(a q) \rightarrow \mathrm{Al}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{3}(a q)+3\mathrm{H}_{2}\mathrm{O}(l)$

Step 9: 3. Write the net ionic equation:

In this case, the net ionic equation is: \(3\mathrm{H}^{+}(a q)+3\mathrm{OH}^{-}(s) \rightarrow 3\mathrm{H}_{2}\mathrm{O}(l)\) d. Complete and balance the reaction and find the products:

Step 10: 1. Identify the products:

In this reaction, nitric acid (HNO3) reacts with barium hydroxide (Ba(OH)2). A salt is formed between the metal ion (Ba) and the non-metal ion (NO3). So, the products will be barium nitrate (Ba(NO3)2) and water (H2O).

Step 11: 2. Balance the reaction:

To balance the equation, we need to add 2 HNO3 on the reactant side and 2 H2O on the product side. The balanced equation is: \(2\mathrm{HNO}_{3}(a q)+\mathrm{Ba}(\mathrm{OH})_{2}(a q) \rightarrow \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2\mathrm{H}_{2}\mathrm{O}(l)\)

Step 12: 3. Write the net ionic equation:

In this case, the net ionic equation is: \(2\mathrm{H}^{+}(a q)+2\mathrm{OH}^{-}(a q) \rightarrow 2\mathrm{H}_{2}\mathrm{O}(l)\)

Key Concepts

Balancing Chemical Equations

Balancing chemical equations is a fundamental skill in chemistry that ensures the law of conservation of mass is maintained. Each side of the equation represents the same total number of atoms for each element involved. For neutralization reactions, this balance involves acids and bases reacting to form water and salts.
Here's a simple way to balance:

• Write down the unbalanced equation.
• Count the number of atoms for each element in the reactants and the products.
• Adjust coefficients, the numbers in front of molecules, to equalize the number of each type of atom on both sides.
• Re-check each element to confirm the conservation of atoms.

Balancing is crucial for accurately describing what occurs in a reaction and is the stepping stone to understanding more complex chemical reactions.

Net Ionic Equations

Net ionic equations strip a chemical reaction down to its essentials by highlighting only the species that directly participate in the reaction. In the context of acid-base reactions, these equations usually involve only the formation of water from hydrogen ions (\(\mathrm{H}^+\)) and hydroxide ions (\(\mathrm{OH}^-\)).
To write a net ionic equation:

• Start with a balanced chemical equation.
• Break down all soluble strong electrolytes into their ions.
• Identify and cancel out spectator ions, which appear unchanged on both sides of the equation.
• Write the resulting simplified equation with only the participating ions.

This approach provides a clearer picture of the chemical process, particularly in complex solutions where multiple reactions might occur at once.

Acid-Base Reactions

Acid-base reactions, also known as neutralization reactions, involve the reaction of an acid with a base to produce water and a salt. These reactions are pivotal in chemistry due to their frequent occurrence and variety of applications.
In a typical neutralization reaction:

• An acid donates protons (\(\mathrm{H}^+\)) to the base.
• The base provides hydroxide ions (\(\mathrm{OH}^-\)) to neutralize the acid.
• The main products are water (\(\mathrm{H}_2\mathrm{O}\)) and a salt, formed from the remaining ions.

Understanding these reactions opens doors to exploring more advanced topics like buffer systems and reaction titrations. Mastering the insights of acid-base reactions also enhances one's ability to predict solubility and reactivity in chemical mixtures.