Question

Select the incorrect pair:

Options

• Soap - Effective in Hard Water

• Detergents - Form Suds Easily

• Soap - Biodegradable

• Detergents - Suitable for Woollens

Answer 1

Soap - Effective in Hard Water

Explanation:

This pair is incorrect because soap is highly ineffective in hard water. Hard water contains dissolved calcium and magnesium ions that chemically react with ordinary soap to form a sticky, insoluble precipitate called soap scum. This reaction prevents the soap from creating a proper lather (suds) and ruins its cleaning ability. Detergents, on the other hand, do not form scum and remain highly effective in hard water.