Question

Write a balanced chemical equation for each acid-base reaction. a. Potassium hydroxide is neutralized by nitric acid. b. Hydrochloric acid is neutralized by barium hydroxide. c. Sulfuric acid is neutralized by ammonium hydroxide.

Short answer

a: \( \text{KOH} + \text{HNO}_3 \rightarrow \text{KNO}_3 + \text{H}_2\text{O} \); b: \( 2 \text{HCl} + \text{Ba(OH)}_2 \rightarrow \text{BaCl}_2 + 2 \text{H}_2\text{O} \); c: \( \text{H}_2\text{SO}_4 + 2\text{NH}_4\text{OH} \rightarrow \text{(NH}_4)_2\text{SO}_4 + 2\text{H}_2\text{O} \).

Step-by-step solution

Identify the Reactants and Products for Reaction a

The reactants in reaction (a) are potassium hydroxide (\( \text{KOH} \)) and nitric acid (\( \text{HNO}_3 \)). The products formed are potassium nitrate (\( \text{KNO}_3 \)) and water (\( \text{H}_2\text{O} \)).

Write the Unbalanced Equation for Reaction a

Write the unbalanced chemical reaction: \( \text{KOH} + \text{HNO}_3 \rightarrow \text{KNO}_3 + \text{H}_2\text{O} \).

Balance the Equation for Reaction a

The equation is already balanced because the number of each type of atom is equal on both sides: \( \text{KOH} + \text{HNO}_3 \rightarrow \text{KNO}_3 + \text{H}_2\text{O} \).

Identify Reactants and Products for Reaction b

For reaction (b), the reactants are hydrochloric acid (\( \text{HCl} \)) and barium hydroxide (\( \text{Ba(OH)}_2 \)). The products are barium chloride (\( \text{BaCl}_2 \)) and water (\( \text{H}_2\text{O} \)).

Write the Unbalanced Equation for Reaction b

Write the unbalanced chemical reaction: \( \text{HCl} + \text{Ba(OH)}_2 \rightarrow \text{BaCl}_2 + \text{H}_2\text{O} \).

Balance the Equation for Reaction b

To balance the equation, we need 2 \( \text{HCl} \) molecules to provide 2 chloride ions, matching the 2 chloride ions in \( \text{BaCl}_2 \): \( 2 \text{HCl} + \text{Ba(OH)}_2 \rightarrow \text{BaCl}_2 + 2 \text{H}_2\text{O} \).

Identify the Reactants and Products for Reaction c

For reaction (c), the reactants are sulfuric acid (\( \text{H}_2\text{SO}_4 \)) and ammonium hydroxide (\( \text{NH}_4\text{OH} \)). The products formed are ammonium sulfate (\( \text{(NH}_4)_2\text{SO}_4\)) and water (\( \text{H}_2\text{O} \)).

Write the Unbalanced Equation for Reaction c

The unbalanced chemical reaction is: \( \text{H}_2\text{SO}_4 + \text{NH}_4\text{OH} \rightarrow \text{(NH}_4)_2\text{SO}_4 + \text{H}_2\text{O} \).

Balance the Equation for Reaction c

To balance the hydrogen and ammonium ions, we need 2 \( \text{NH}_4\text{OH} \) to provide the correct amount of ammonium, matching \( \text{(NH}_4)_2\text{SO}_4 \): \( \text{H}_2\text{SO}_4 + 2\text{NH}_4\text{OH} \rightarrow \text{(NH}_4)_2\text{SO}_4 + 2\text{H}_2\text{O} \).

Key concepts

Acid-Base Reactions

Acid-base reactions are a fundamental type of chemical reaction where an acid reacts with a base to produce a salt and water. This is known as neutralization. Acids are substances that donate protons (H^+), while bases accept protons. This exchange leads to the formation of water and an ionic compound, generally referred to as a salt.
For example, the reaction between potassium hydroxide (KOH) and nitric acid (HNO_3) demonstrates this process. The acid (HNO3) and the base (KOH) react to form potassium nitrate (KNO_3) and water (H_2O).

• Acids react with bases to neutralize each other.
• Products of an acid-base reaction typically include water and a salt.

Recognizing these features helps in predicting the products of similar reactions. Understanding acid-base reactions lays the groundwork for exploring the broader topic of chemical reactions and balancing equations.

Molecule Balancing

Balancing chemical equations is crucial because it reflects the law of conservation of mass. This law states that matter is neither created nor destroyed in a chemical reaction. Thus, the number of atoms for each element should be equal on both sides of the equation.
Let's take, for instance, the reaction between hydrochloric acid (HCl) and barium hydroxide (Ba(OH)_2). Initially, the equation is unbalanced: HCl + Ba(OH)_2  forms BaCl_2 + H_2O. In order to balance it, we note that two chloride ions are needed. Thus, the balanced form becomes 2HCl + Ba(OH)_2  -> BaCl_2 + 2H_2O.

• Check the number of each type of atom on both sides of the equation.
• Adjust coefficients, not subscripts, to balance atoms.
• Re-assess to ensure balance is maintained across both reactants and products.

Mastering molecule balancing skills is key to successfully tackling more complex chemical reactions.

Chemical Reactants

In any chemical reaction, the substances that start off or participate in the reaction are called reactants. Their molecular structures define what kinds of products can be formed from the reaction.
Consider the acid-base reaction in scenario (c) where sulfuric acid (H_2SO_4) reacts with ammonium hydroxide (NH_4OH). Here, sulfuric acid is the acid, and ammonium hydroxide is the base.

• Reactants are consumed during the reaction.
• Their specific chemical properties and amounts directly influence the resulting products.
• Knowing the reactants allows for the prediction and balancing of the corresponding equation.

Understanding the role and nature of chemical reactants is fundamental in comprehending how chemical reactions occur and the outcomes they produce.

Chemical Products

The substances formed from a chemical reaction are known as products. The properties of the reactants largely determine the characteristics of these products.
Taking the example of the reaction between sulfuric acid H_2SO_4 and ammonium hydroxide NH_4OH, the products formed are ammonium sulfate (NH_4)_2SO_4 and water H_2O. Ammonium sulfate is the salt resulting from the acid-base neutralization of this particular pair.

• Products can include salts, water, gases, or other compounds, based on the reaction type.
• In acid-base reactions, water and a salt are typically the primary products.
• Identifying products helps in balancing chemical equations accurately.

Recognizing and understanding the products of chemical reactions aids in grasping the broader scope and implications of these chemical processes.