All Exams Test series for 1 year @ ₹349 only
Question

A stain of curry on a white cloth become reddish brown when soap is used because the soap is:

The correct answer is

Basic in nature

Curry Stain Chemistry: Soap’s Effect

The color change observed when soap interacts with a curry stain on white cloth is due to the chemical properties of the ingredients involved.

Understanding the Color Change

  • Indicator Property: Curry stains often contain turmeric, a natural compound that acts as a pH indicator. Turmeric is typically yellow in color.

  • pH and Color Variation: Turmeric exhibits different colors depending on the acidity or alkalinity (pH) of its environment. It appears yellow in neutral or acidic conditions but changes to a reddish-brown hue in basic (alkaline) conditions.

  • Nature of Soap: Soaps are generally manufactured using alkaline substances (like sodium hydroxide) and are therefore basic in nature.

  • Reaction: When soap, being basic, comes into contact with the turmeric in the curry stain, it alters the pH. This shift to a basic environment causes the turmeric indicator to change its color from yellow to reddish-brown.

Therefore, the soap is basic in nature, causing the color change.

Was this answer helpful?

Important Questions from Equilibrium

  1. To test whether something is acidic or alkaline, we can use either a litmus paper or _______

  2. Bitter tasting food is ______ in nature.

  3. Which of the following statements is true?

  4. In a neutralisation reaction, a new substance is formed, called _____.

  5. Acidic and basic solutions in water conduct electricity because they produce ______ and hydroxide ion, respectively.

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App