Question

State whether each of the following solutions is acidic, basic, or neutral: a. soda, \(\mathrm{pH} 3.22\) b. shampoo, \(\mathrm{pH} 5.7\) c. laundry detergent, \(\mathrm{pH} 9.4\) d. rain, \(\mathrm{pH} 5.83\) e. honey, \(\mathrm{pH} 3.9\) f. cheese, \(\mathrm{pH} 5.2\)

Short answer

Soda, shampoo, rain, honey, and cheese are acidic. Laundry detergent is basic.

Step-by-step solution

- Understand pH scale

The pH scale ranges from 0 to 14. A pH of 7 is neutral, below 7 is acidic, and above 7 is basic.

- Analyze the pH value of soda

Given: soda, \( \mathrm{pH} 3.22 \). Since 3.22 is less than 7, soda is acidic.

- Analyze the pH value of shampoo

Given: shampoo, \( \mathrm{pH} 5.7 \). Since 5.7 is less than 7, shampoo is acidic.

- Analyze the pH value of laundry detergent

Given: laundry detergent, \( \mathrm{pH} 9.4 \). Since 9.4 is greater than 7, laundry detergent is basic.

- Analyze the pH value of rain

Given: rain, \( \mathrm{pH} 5.83 \). Since 5.83 is less than 7, rain is acidic.

- Analyze the pH value of honey

Given: honey, \( \mathrm{pH} 3.9 \). Since 3.9 is less than 7, honey is acidic.

- Analyze the pH value of cheese

Given: cheese, \( \mathrm{pH} 5.2 \). Since 5.2 is less than 7, cheese is acidic.

Key concepts

acidic solutions

Acidic solutions have a pH value less than 7. This means they have more hydrogen ions \(H^+\) than hydroxide ions \(OH^-\). Examples of acidic solutions include:

• Soda, with a pH of 3.22
• Shampoo, with a pH of 5.7
• Rain, with a pH of 5.83
• Honey, with a pH of 3.9
• Cheese, with a pH of 5.2

These substances are all on the acidic side of the pH scale. Since their pH values are below 7, they are considered acidic. Most foods and beverages with tart or sour taste are acidic. Understanding the properties of acidic solutions can help in predicting their reactions and behavior in different environments.

basic solutions

Basic solutions, also known as alkaline solutions, have a pH value greater than 7. They contain more hydroxide ions \(OH^-\) than hydrogen ions \(H^+\). Examples of basic solutions include:

• Laundry detergent, with a pH of 9.4
  

Substances like laundry detergents are basic and are excellent for cleaning because they can react with oils and fats to form soaps. Basic solutions often feel slippery to the touch and can also be corrosive. Knowing the pH of a solution helps in figuring out its basicity and suitable applications.

neutral solutions

Neutral solutions have a pH value of exactly 7. This means they have an equal number of hydrogen ions \(H^+\) and hydroxide ions \(OH^-\). A classic example of a neutral solution is pure water. Neutral solutions do not exhibit the properties of acids or bases.

Understanding neutral solutions is essential because they serve as a baseline for measuring the acidity or basicity of other solutions. They are helpful in many biological and chemical processes where a balanced pH is crucial for maintaining stability and proper function.

pH value analysis

Analyzing the pH value of a solution helps to determine whether it is acidic, basic, or neutral. The pH scale ranges from 0 to 14:

• pH < 7: Acidic
• pH = 7: Neutral
• pH > 7: Basic

The formula for calculating pH is \(pH = -\log[H^+]\), where \(\log\) is the base-10 logarithm and \( [H^+] \) is the concentration of hydrogen ions in moles per liter. Solutions like soda, shampoo, honey, and cheese are acidic, evidenced by their pH values below 7. Laundry detergent is basic with a pH above 7. Neutral solutions like pure water have a pH of exactly 7.

Understanding pH value analysis is important in various fields such as chemistry, biology, medicine, and environmental science. It helps us predict chemical behaviors, maintain biological balances, and solve everyday practical problems.