What is a pH test?

A pH test is a procedure used to determine how acidic or basic a substance is. The pH scale ranges from 0 to 14, with 7 as the neutral point.

Understanding pH

The pH of a substance indicates its acidity or basicity. According to the reference, a substance is considered:

• Acidic: If its pH value is less than 7.
• Basic (or alkaline): If its pH value is greater than 7.
• Neutral: If its pH value is exactly 7.

Pure water has a pH of 7 and serves as a neutral reference point for comparison.

How pH Testing Works

pH testing can be performed using various methods, including:

• pH Meters: These electronic devices provide highly accurate pH measurements.
• pH Strips: These are paper strips treated with chemicals that change color based on the pH level.
• Liquid pH Reagents: These solutions change color when mixed with the test substance, indicating the pH level.

Practical Applications

pH testing is used in numerous fields, such as:

• Chemistry: Understanding chemical reactions and processes.
• Biology: Studying cellular functions and enzyme activity.
• Agriculture: Analyzing soil quality for optimal plant growth.
• Environmental Science: Monitoring water pollution.
• Food and Beverage Industry: Ensuring quality and safety standards.
• Healthcare: Monitoring bodily fluids and diagnosing certain medical conditions.

pH Scale

Here's a basic overview of the pH scale and what different levels signify:

pH Value	Acidity/Basicity	Examples
0	Strongly Acidic	Battery acid
1	Acidic	Gastric acid
2	Acidic	Lemon juice
3	Acidic	Vinegar
4	Slightly Acidic	Tomato juice
5	Slightly Acidic	Black coffee
6	Slightly Acidic	Milk
7	Neutral	Pure water
8	Slightly Basic	Sea water
9	Basic	Baking soda solution
10	Basic	Milk of magnesia
11	Basic	Ammonia solution
12	Basic	Bleach
13	Strongly Basic	Liquid drain cleaner
14	Strongly Basic	Sodium hydroxide (lye)

Understanding pH levels is crucial in many scientific and everyday applications.