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Acids, Bases, And Litmus

Define acidic, basic, and neutral substances and introduce Litmus as the primary indicator.

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Sour and Slippery

Setting the context for everyday acids and bases.

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Sour and Slippery Concepts
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Not all 'Limes' are the same

Distinguishing lime fruit from lime water.

🍋‍🟩 The fruit lime is similar to a lemon and contains citric acid. But the lime water used in science labs is completely different—it is a basic solution made by mixing calcium oxide (chuna) in water!
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What are Acids and Bases?

Explanation of the properties of acids and bases.

Substances that taste sour tend to contain acids and are acidic in nature.

Common edible examples include Lemons and Oranges (citric acid), Amla (ascorbic acid and citric acid), and Tamarind (tartaric acid).

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Acids in Our Food

Visual mapping of common fruits to their internal acids.

Bold editorial infographic, clean data-forward design mapping common fruits to their natural acids: Orange and Lemon pointing to Citric Acid, Amla pointing to Ascorbic Acid, Tamarind pointing to Tartaric Acid, and Tomatoes pointing to Citric and Oxalic Acid. High-contrast color blocks, elegant typography hierarchy, geometric shapes and icons, professional magazine layout quality, 3-4 color maximum.
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Common edible substances and the natural acids present in them.

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The Litmus Test

Comparison of blue and red litmus paper reactions.

Clean side-by-side comparison diagram showing the Litmus Test. Left side shows a drop of acidic lemon juice falling on a blue litmus strip, turning the spot red. Right side shows a drop of basic soap solution falling on a red litmus strip, turning the spot blue. Consistent visual treatment for both sides, same scale and style, pastel color coding to distinguish categories, elegant typography, white background, generous whitespace.
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Acids turn blue litmus red, and bases turn red litmus blue.

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Litmus: The Natural Indicator

Introduction to indicators and litmus extracted from lichens.

How do we safely test a substance without tasting it? We use an acid-base indicator—special substances that change color in acidic or basic solutions.

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Classifying Solutions

Matrix showing how different solutions react to litmus.

Acidic Solutions

  • Examples: Vinegar, lemon juice
  • Blue Litmus: Turns Red
  • Red Litmus: Remains Red

Basic Solutions

  • Examples: Soap, baking soda
  • Blue Litmus: Remains Blue
  • Red Litmus: Turns Blue

Neutral Solutions

  • Examples: Tap water, sugar
  • Blue Litmus: No change
  • Red Litmus: No change