Back to acids bases and salts
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Indicator Hunt

Use ALL the NCERT Class 10 indicators — Litmus, Turmeric, China Rose, Phenolphthalein, Methyl Orange, Universal Indicator, Onion, Vanilla & Clove Oil — to identify two mystery solutions (an Acid and a Base).

How It Works

1

Two Mystery Solutions

Tubes A and B contain an Acid (e.g. HCl) and a Base (e.g. NaOH) — in random order. Use indicators to find out which is which.

2

10 NCERT Indicators — Three Types

Pick from 4 NATURAL indicators (Blue Litmus, Red Litmus, Turmeric, China Rose), 3 SYNTHETIC indicators (Phenolphthalein, Methyl Orange, Universal Indicator), and 3 OLFACTORY indicators (Onion, Vanilla, Clove Oil).

3

Natural vs Synthetic vs Olfactory

Litmus, Turmeric & China Rose are natural (from living things). Phenolphthalein, Methyl Orange & Universal Indicator are synthetic (lab-made dyes). Onion, Vanilla & Clove Oil are olfactory — they reveal the base by losing their characteristic smell.

4

Cross-Check, Then Identify

Each indicator gives one clue. Add 2-3 indicators to each tube to be sure, then assign Acidic / Basic to each sample.

Reaction Key

Acidic Solution (e.g. HCl):

Universal Indicator → Red/Orange (pH ≈ 2)

Phenolphthalein → Colorless

Methyl Orange → Red

Blue Litmus → Turns Red (Red Litmus stays Red)

Turmeric → Stays Yellow

China Rose → Dark Pink/Magenta

Onion, Vanilla & Clove Oil → Smell REMAINS

Basic Solution (e.g. NaOH):

Universal Indicator → Blue/Violet (pH ≈ 12)

Phenolphthalein → Bright Pink

Methyl Orange → Yellow

Blue Litmus → Stays Blue (Red Litmus → Turns Blue)

Turmeric → Turns Red-Brown

China Rose → Green

Onion, Vanilla & Clove Oil → Smell DESTROYED