Although soap and detergent are often referred to interchangeably, they are in fact chemically very different from each other.

Soap

• Is a potassium or sodium salt of a carboxylic acid with a long aliphatic chain attached to it
• Is hydrophilic due to the presence of carboxylate at the end of its molecular structure
• Derived from natural sources, usually through saponification of vegetable oils and animal fats
• Is biodegradable and environment-friendly
• Not effective in hard water or saline water

Detergent

• Is a potassium or sodium salt of a long alkyl chain ending with a sulfonate group
• Is soluble in hard water because the sulfonate group does not attach itself to the ions present in water
• Is a synthetic derivative and not easily biodegradable
• Do not lose their effectiveness in hard water or saline water