Question

An acidic solution is added to a basic solution. If the resulting solution is basic, is the acid or the base the limiting reactant?

Short answer

In this case, the acid is the limiting reactant.

Step-by-step solution

Understand the Concept of Acid and Base

Acids are substances that release hydrogen ions (H+) when dissolved in water, while bases are substances that release hydroxide ions (OH-) when dissolved in water. A neutralization reaction occurs when an acid reacts with a base to form water and a salt.

Define Limiting Reactant

A limiting reactant is the reactant that is completely consumed in a chemical reaction. Once this reactant is used up, the reaction stops and no more products are formed.

Analyze Given Condition

If after the reaction the resulting solution is still basic, this means there are excess base (OH-) ions. There was less acid present to react with all of the base ions, resulting in leftover base ions.

Key concepts

Limiting Reactant

In a chemical reaction, the limiting reactant plays a crucial role in determining when the reaction will stop. It is the substance that gets entirely consumed first during the reaction, thus preventing more product from being formed. For reactions involving acids and bases, determining the limiting reactant is essential to predict the final state of the solution, such as whether it will be acidic, neutral, or basic.

• If an acidic solution is added to a basic one and the final solution is still basic, this indicates that the acid was the limiting reactant.
• Because there was not enough acid to neutralize all of the base, some base remains, making the solution basic.

Knowing which reactant is limiting helps in calculations and understanding the extent of a reaction.

Neutralization Reaction

Neutralization reactions are fundamental processes in chemistry in which an acid and a base react to form water and a salt. This type of reaction is essential for adjusting the pH of a solution to make it more neutral.

• During a neutralization reaction, hydrogen ions ( H^+ ) from the acid combine with hydroxide ions ( OH^- ) from the base, forming water ( H_2O ).
• The remaining ions typically form a salt, depending on the acid and base used.

This reaction is crucial on a daily basis, playing a significant role in areas like medicine, industry, and environmental management. Neutralization is also vital in controlling chemical processes and ensures safety in neutralizing corrosive substances.

Hydrogen Ions

Hydrogen ions, denoted as ( H^+ ), are fundamental to the concept of acidity. When an acid dissolves in water, it releases these ions, which increase the concentration of ( H^+ ) in the solution. This increase in hydrogen ions leads to the acidic characteristics of the solution.

• Acids have low pH values, usually less than 7, which indicates a higher concentration of hydrogen ions.
• The stronger the acid, the more ( H^+ ) it releases.

Understanding hydrogen ions helps us determine the acidic strength of a solution and is pivotal in analyzing reactions where acids are involved.

Hydroxide Ions

Hydroxide ions, represented as ( OH^- ), are integral to understanding basic or alkaline solutions. They are released when bases dissolve in water, leading to an increase in pH values of the solution. This gives the solution its characteristic basic properties.

• Bases that release ( OH^- ) ions often result in a pH value greater than 7, indicating their alkaline nature.
• In a neutralization reaction, ( OH^- ) ions react with ( H^+ ) ions from the acid to form water, thus neutralizing the solution.

The role of hydroxide ions is vital in reactions where controlling pH levels is important, such as in industrial cleaning, biochemical processes, and environmental applications.