Problem 55 - Chemistry Matter and Change

Question

In terms of ion concentrations, distinguish between acidic, neutral, and basic solutions.

Step-by-Step Solution

Answer

In terms of ion concentrations, acidic, neutral, and basic solutions can be distinguished as follows: 1. In an acidic solution: \( [H^{+}] > [OH^{-}] \), meaning the concentration of hydrogen ions (H+) is greater than the concentration of hydroxide ions (OH-). 2. In a neutral solution: \( [H^{+}] = [OH^{-}] \), meaning the concentration of hydrogen ions (H+) is equal to the concentration of hydroxide ions (OH-). 3. In a basic solution: \( [OH^{-}] > [H^{+}] \), meaning the concentration of hydroxide ions (OH-) is greater than the concentration of hydrogen ions (H+).

Step 1: Understanding the Ion Concentrations

In a solution, there are hydrogen ions (H+) and hydroxide ions (OH-). The concentration of these ions determines whether a solution is acidic, neutral, or basic. We will use their concentrations to distinguish between these types of solutions.

Step 2: Ion Concentrations in an Acidic Solution

In an acidic solution, the concentration of hydrogen ions (H+) is greater than the concentration of hydroxide ions (OH-). In other words, it can be represented as: \( [H^{+}] > [OH^{-}] \) Here, the square brackets indicate the concentration of the respective ions.

Step 3: Ion Concentrations in a Neutral Solution

In a neutral solution, the concentration of hydrogen ions (H+) is equal to the concentration of hydroxide ions (OH-). This can be represented as: \( [H^{+}] = [OH^{-}] \)

Step 4: Ion Concentrations in a Basic Solution

In a basic (alkaline) solution, the concentration of hydroxide ions (OH-) is greater than the concentration of hydrogen ions (H+). This can be represented as: \( [OH^{-}] > [H^{+}] \)

Step 5: Summary

To distinguish between acidic, neutral, and basic solutions in terms of ion concentrations, remember the following: 1. In an acidic solution: \( [H^{+}] > [OH^{-}] \) 2. In a neutral solution: \( [H^{+}] = [OH^{-}] \) 3. In a basic solution: \( [OH^{-}] > [H^{+}] \) By comparing the concentrations of hydrogen ions (H+) and hydroxide ions (OH-) in a solution, you can determine whether the solution is acidic, neutral, or basic.

Key Concepts

Acidic Solutions

Acidic solutions are an important part of understanding the pH scale. They are characterized by having a higher concentration of hydrogen ions \([H^{+}]\) compared to hydroxide ions \([OH^{-}]\). This results in a pH value that is less than 7.
Acids are substances that increase the hydrogen ion concentration in a solution.
Common examples include lemon juice, vinegar, and gastric acid.
An easy way to remember this is that the more hydrogen ions present, the lower the pH.
In chemical reactions, acidic solutions often release protons, influencing reactions and the behavior of other substances.
This is why acids can be corrosive and are effective at breaking down other materials.

Neutral Solutions

Neutral solutions are those that have a balance between hydrogen ions \([H^{+}]\) and hydroxide ions \([OH^{-}]\).
This balance means that the pH is exactly 7, which is considered neutral on the pH scale.
Water is the most common example of a neutral solution. However, not all water is neutral due to added minerals or impurities.
The neutrality of these solutions plays a crucial role in various environmental and biological processes.In biological systems, a neutral pH is essential for maintaining homeostasis, allowing enzymes and cells to function optimally.
In its pure form, a neutral solution does not favor either proton release or acceptance, making it stable in many reactions and processes.

Basic Solutions

Basic solutions, also known as alkaline solutions, have a higher concentration of hydroxide ions \([OH^{-}]\) than hydrogen ions \([H^{+}]\).
Their pH value is greater than 7, indicating their basic nature.
Common examples of basic substances include baking soda, soap, and bleach.Basic solutions tend to accept protons and can neutralize acids to form water and salts.
This quality makes them useful in various industries, such as cleaning and manufacturing.
Just like acids, strong bases can also be corrosive, but they often feel slippery to the touch.
Recognizing whether a solution is basic is crucial for chemical safety and for carrying out chemical reactions responsibly.
By understanding these properties, you can predict reactions and characteristics of basic solutions effectively.