Chemistry: Acids, Bases, and pH

Acids and Bases

• Identification of Acids:

  • Any compound that starts with an 'H' is classified as an acid.

  • Example: HCl (hydrochloric acid)

• Identification of Bases:

  • Any compound that ends with 'OH' is classified as a base.

  • Example: NaOH (sodium hydroxide)

pH Scale

• The pH scale measures the acidity or alkalinity of a solution.

• Values range from 0 to 14:

  • Acidic solutions: pH < 7

  • Neutral solutions: pH = 7

  • Alkaline (basic) solutions: pH > 7

pH Levels:

• 0 - Strongly acidic

• 1

• 2

• 3

• 4

• 5

• 6

• 7 - Neutral

• 8

• 9

• 10

• 11

• 12

• 13

• 14 - Strongly alkaline

Important Equation

• The relationship between pH and pOH is expressed as:

  • pH + pOH = 14

• This equation helps in calculating one if the other is known, indicating their inverse relationship in aqueous solutions.

Identification of Acids: Any compound that starts with an 'H' is classified as an acid.

Example: HCl (hydrochloric acid)

Identification of Bases: Any compound that ends with 'OH' is classified as a base.

Example: NaOH (sodium hydroxide)

pH Scale

The pH scale measures the acidity or alkalinity of a solution.

Values range from 0 to 14: Acidic solutions: pH < 7; Neutral solution: pH = 7; Basic solutions: pH > 7.

Important Equation

The relationship between pH and pOH is expressed as: pH + pOH = 14

This equation helps in calculating one if the other is known, indicating their inverse relationship in aqueous solutions.

Example of pH Calculation: If a solution has a pH of 3, then pOH can be calculated as follows:

ext{pOH} = 14 - ext{pH} = 14 - 3 = 11.