Problem 55 - Chemistry Matter and Change

Question

Predict What type of product would the following reaction be most likely to produce? Explain your reasoning. $$\mathrm{Ba}(\mathrm{OH})_{2}(\mathrm{aq})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow$$

Step-by-Step Solution

Answer

The reaction produces barium chloride (\( \text{BaCl}_2 \)) and water (\( \text{H}_2\text{O} \)).

Step 1: Identify the type of reaction

The given reaction involves a compound with hydroxide ions, \( \text{Ba(OH)}_2 \), reacting with an acid, \( 2\text{HCl} \). This is a neutralization reaction, which typically occurs when an acid reacts with a base to produce a salt and water.

Step 2: Recognize the reaction components

In this reaction, \( \text{Ba(OH)}_2 \) is the base, and \( 2\text{HCl} \) is the acid. The combination of \( \text{OH}^- \) from the base and \( \text{H}^+ \) from the acid results in water formation: \( \text{H}_2\text{O} \). Meanwhile, the \( \text{Ba}^{2+} \) and \( \text{Cl}^- \) ions will form a salt.

Step 3: Predict the products

When the hydroxide reacts with the acid's hydrogen ions, \( \text{H}_2\text{O} \) (water) is formed. The remaining ions, \( \text{Ba}^{2+} \) and \( 2\text{Cl}^- \), combine to form \( \text{BaCl}_2 \) (barium chloride). Thus, the complete products of the reaction are \( \text{BaCl}_2 \) and \( \text{H}_2\text{O} \).

Step 4: Write the balanced equation

The balanced chemical equation that represents the reaction is \[ \text{Ba(OH)}_2(\text{aq}) + 2\text{HCl}(\text{aq}) \rightarrow \text{BaCl}_2(\text{aq}) + 2\text{H}_2\text{O}(\text{l}) \]. This balanced equation confirms the predictions of the reaction products: barium chloride and water.

Key Concepts

acid-base reaction

In chemistry, an acid-base reaction represents a fundamental type of chemical interaction. This occurs when an acid reacts with a base. The result is the formation of a salt and water. In this particular reaction, we have barium hydroxide, a base, and hydrochloric acid, an acid. When these two substances interact, the

• hydrogen ions ( H^+ ) from the acid and
• hydroxide ions ( OH^- ) from the base join together to form water ( H_2O ).

The remaining components, barium and chloride ions, complete the formation of a salt, specifically barium chloride in this case. Thus, an acid-base reaction typically follows this pattern of neutralizing acid and base to produce a neutral salt and water.
Understanding this type of reaction is crucial because it highlights the way substances interact at a molecular level to achieve a state of equilibrium, effectively "neutralizing" each other's reactive properties through this exchange.

barium hydroxide

Barium hydroxide, Ba(OH)_2 , is a chemical compound consisting of barium, oxygen, and hydrogen. It is a strong base, which means it can readily dissociate in water to produce hydroxide ions ( OH^- ). These ions are negatively charged and play a key role in the neutralization process during reactions with acids. When Ba(OH)_2 interacts with an acid, the hydroxide ions find and neutralize the hydrogen ions ( H^+ ) from the acid, forming water in the process.

• This characteristic of easily donating hydroxide ions makes barium hydroxide particularly powerful in neutralization reactions.
• It effectively breaks down the acid components to form safer and more stable products: water and salt.

In this neutralization with hydrochloric acid, not only are water molecules produced, but the remaining ions, barium and chloride, join to form barium chloride, contributing to the equation's development.

hydrochloric acid

Hydrochloric acid, known chemically as HCl , is a strong acid widely used in both industrial and laboratory settings. It consists of hydrogen ( H^+ ) and chloride ( Cl^- ) ions. Due to its strong acidity, HCl readily dissociates in water, releasing hydrogen ions.
In an acid-base reaction, such as with barium hydroxide, these hydrogen ions are key participants.

• The hydrogen ions react with the hydroxide ions released by barium hydroxide, forming water ( H_2O ) molecules.
• This reaction effectively reduces the "acidic" character of the solution, neutralizing it in the process.

The leftover chloride ions are free to pair with the barium ions, creating barium chloride—an illustrative product of this chemical reaction.
This example of hydrochloric acid in action displays its reactivity and its role as a reactant in neutralization processes.

barium chloride

Barium chloride, BaCl_2 , emerges as a product from the neutralization of barium hydroxide and hydrochloric acid. It is a salt composed of barium and chloride ions. During the reaction, once the hydroxide ions and hydrogen ions have combined to form water, the remaining

• barium ions ( Ba^{2+} )
• chloride ions ( Cl^- )

combine to form barium chloride. This process exemplifies the creation of a salt from an acid-base reaction.
Barium chloride is generally found in a crystallized form and is highly soluble in water, making it useful in various chemical processes.
Understanding how barium chloride forms helps chemists predict product outcomes in neutralization reactions and offers insights into the behavior of ionic compounds in the aqueous solutions.