Question

Solution A has a pH of 2, and solution \(\mathrm{B}\) has a \(\mathrm{pH}\) of 10 . Which of these statements about these solutions is true? a. Solution A has a higher \(\mathrm{H}^{+}\)concentration than solution \(\mathrm{B}\). b. Solution B is basic. c. Solution A is acidic. d. All of these are true.

Short answer

d. All of these are true.

Step-by-step solution

Statement A: Solution A has a higher H+ concentration than solution B

Since solution A has a pH of 2 and solution B has a pH of 10, we can tell without doing any calculations that solution A is more acidic than solution B because its pH is lower. The concentration of H+ ions is greater in an acidic solution compared to a basic one. Therefore, statement A is true.

Statement B: Solution B is basic

Solution B has a pH of 10, which is greater than 7. This indicates that the solution is basic. Hence, statement B is true.

Statement C: Solution A is acidic

Solution A has a pH of 2, which is less than 7. This indicates that the solution is acidic. Hence, statement C is true. Since all the statements A, B, and C are true, the correct answer is:

Answer

d. All of these are true.

Key concepts

Acidic Solutions

Acidic solutions are characterized by having a pH value less than 7. The pH scale ranges from 0 to 14 and measures how acidic or basic a solution is.
When a solution has a low pH, it indicates a high concentration of hydrogen ions (\( \text{H}^{+}\)).
This is why solution A, with a pH of 2, is considered acidic.
Here are some important points about acidic solutions:

• They taste sour and can be corrosive.
• Common examples include lemon juice and vinegar.
• Instruments like pH meters or indicators are used to measure acidity accurately.

Understanding acidic solutions is crucial in chemistry as they play vital roles in various processes, from digestion in the human body to industrial applications.

Basic Solutions

Basic solutions, also known as alkaline solutions, have a pH value greater than 7. They contain fewer hydrogen ions and more hydroxide ions (\( \text{OH}^{-}\)).
In the given exercise, solution B has a pH of 10, placing it firmly in the basic category.
Here are some key aspects of basic solutions:

• They often feel slippery to the touch.
• Common examples include baking soda and soap water.
• Basic solutions neutralize acids, which is useful in various chemical reactions.

Understanding basic solutions helps us in everyday tasks, such as cleaning and even cooking. Knowing the properties of both acidic and basic solutions allows us to utilize them effectively in various applications.

Hydrogen Ion Concentration

The hydrogen ion concentration in a solution is pivotal in determining its pH level. The pH scale is logarithmic, meaning each integer change represents a tenfold difference in (\( \text{H}^{+}\)) concentration.
For instance, a decrease in pH from 3 to 2 means the hydrogen ion concentration has increased ten times.
Here are some important things to know about hydrogen ion concentration:

• It directly influences the chemical properties of a solution.
• A high concentration indicates a more acidic solution.
• A lower concentration is associated with a more basic (alkaline) solution.

Grasping the concept of hydrogen ion concentration is essential for solving chemistry problems related to pH and understanding how different substances interact with each other. It explains why solution A is more acidic than solution B due to its higher (\( \text{H}^{+}\)) concentration.