Teacher Pacing Guide Color Shift Chemistry
Teacher Pacing Guide: 2-Week pH Unit (2 Days/Week)
Week 1: The pH Scale & Cabbage Chemistry
Day 1 Introduction to Acids & Bases
0-10 min: Hook - The "Invisible Ink" demo (Lemon juice + Heat or Phenolphthalein).10-30 min: Instructional Slides: What is pH? Acids vs. Bases properties.30-50 min: Guided Practice: "pH Scale Explorer" worksheet.50-60 min: Exit Ticket: Name 2 acids and 2 bases in your kitchen.
Day 2 The Red Cabbage Lab
0-15 min: Lab Safety & Making the Indicator (Boiling/Blending red cabbage).15-45 min: Lab Rotation: Testing 6-8 household liquids (Vinegar, Soap, Soda, Bleach-diluted).45-60 min: Clean up and Data Analysis (Comparing colors to the pH key).
Week 2: Reactions & Mastery
Day 3 Butterfly Pea Tea Reactions
0-15 min: Introduction to Butterfly Pea Flower Tea (Natural anthocyanins).15-40 min: "Magic Color Change" Experiment: Adding lemon juice (acid) then baking soda (base) to observe shifts.40-55 min: Discussion: Neutralization reactions and molecular changes.55-60 min: Quick Reflection: Why does the tea change back to blue?
Day 4 Review & Assessment
0-20 min: "pH Jeopardy" or Review Game (Testing knowledge of the scale).20-50 min: Summative Assessment: "Color Shift Quiz".50-60 min: Unit Wrap-up: Real-world applications (Soil pH, Ocean Acidification).
Lab Prep Checklist
For Day 2:
1 Large Red Cabbage
Hot water or blender
Filter paper/Strainers
Clear plastic cups
Household samples (Vinegar, Ammonia, etc.)
For Day 3:
Dried Butterfly Pea Flowers
Lemon juice & Baking soda
Hot water & stir sticks
Graduated cylinders or clear cups
pH Power Slides pH Power
The Secret Language of Acids & Bases
Day 1: Introduction
What is pH?
pH stands for "Potential Hydrogen."
It measures how many Hydrogen ions (\(H^+\)) are in a solution.
More \(H^+\) = Acidic
Less \(H^+\) = Basic (Alkaline)
0-14
The Range
The pH Scale
0 7 14
Acids
"Sharp & Sour"
pH 0 - 6.9
Neutral
"Pure & Plain"
pH 7.0
Bases
"Bitter & Slippery"
pH 7.1 - 14
Who's Who?
Acids
🍋 Lemon Juice (pH 2)
🔋 Battery Acid (pH 0)
🍎 Vinegar (pH 3)
Bases
🧼 Soap (pH 9-10)
🍞 Baking Soda (pH 8)
✨ Bleach (pH 13)
pH Scale Explorer Worksheet pH Scale Explorer
Foundations of Chemistry: Lesson 1
Name:
Date:
1
Defining pH
What does the letters "pH" actually stand for?
Fill in the blanks:
Solutions with a high concentration of ions are considered , while solutions with a low concentration are considered .
2
Mapping the Scale
Label the scale below. Mark the Acidic, Neutral, and Basic zones, and write the pH number for each point.
Most Acidic
Most Basic
pH Number
pH Number
pH Number
3
Who's Who?
Classify the following household items as Acid (A), Base (B), or Neutral (N).
Orange Juice
Liquid Hand Soap
Distilled Water
Ammonia Cleaner
Stomach Acid
Baking Soda
4
Prediction
If you mixed a strong acid (like lemon juice) with a strong base (like baking soda), what do you think would happen to the pH of the mixture? Why?
Cabbage Chemistry Lab Report Cabbage Chemistry
Student Lab Report & Guide
Name:
Period:
Objective
Use red cabbage juice as a natural pH indicator to identify the acidity or alkalinity of common household substances.
Safety
• Wear safety goggles at all times.
• Do NOT taste any chemicals or liquids.
• Wash hands immediately if liquids touch skin.
Hypothesis
If I add red cabbage juice to an unknown liquid, then its color will change because...
Data & Observations
Substance Initial Color Final Color (with Indicator) Acid, Base, or Neutral? Lemon Juice Vinegar Baking Soda Soln. Soapy Water Antacid Tablet Soln. Distilled Water
Cabbage Juice pH Reference Key
Red (pH 2)
Pink (pH 4)
Purple (pH 7)
Blue (pH 8)
Green (pH 10)
Yellow (pH 12)
Analysis & Conclusion
1. Which substances tested were the most acidic? How did you know based on the color?
2. What color did the cabbage juice turn when mixed with a neutral substance?
3. Research or reflect: Why does red cabbage work as a pH indicator? (Hint: Think about the pigment name mentioned in class).
Did You Know?
Red cabbage contains molecules called anthocyanins . These change shape and color depending on the concentration of hydrogen ions around them!
Magic Tea Slides Magic Tea Reactions
The Science of Butterfly Pea Flowers
The Blue Wonder
Butterfly Pea Flower tea is naturally vivid blue.
The Secret Ingredient:
"Anthocyanins" — The same pigments found in red cabbage and blueberries!
The "Magic" Shift
pH 7+
NEUTRAL
pH 2-4
ACIDIC
Adding lemon juice (acid) changes the molecule's shape, reflecting pink/purple light instead of blue!
Can We Go Back?
Neutralization
When we add a Base (like Baking Soda) to the Acidic tea, they cancel each other out.
Acid + Base = Neutral Solution
🍋
Lemon Juice makes it Pink
🧂
Baking Soda makes it Blue again!
Magic Tea Lab Handout Magic Tea Lab
Neutralization & Reversible Reactions
Scientist:
The Mystery
"Butterfly Pea Flower tea is famous for its bright blue color. But what happens when we mess with its chemistry? Today, we will perform a 'magic' trick that uses the power of acids and bases to change color and then change it back!"
1 Experimental Steps
Step 1: The Base
Observe the plain Butterfly Pea Tea. Describe its appearance.
Step 2: The Acid
Add 5-10 drops of Lemon Juice. What happened?
Step 3: The Neutralizer
Slowly add a pinch of Baking Soda. Stir gently. What happens to the color? Why do you think it is returning to its original state?
2 Reaction Analysis
What is a Neutralization Reaction?
Explain in your own words what happens when an acid and a base are mixed together in equal amounts.
The Molecular "Flip"
Anthocyanin pigments change shape when they encounter \(H^+\) ions. Based on your results, are these pigments permanent or reversible indicators?
Color Shift Chemistry Unit • Lesson 3
pH Mastery Review Slides Mastery
Unit Review
Let's Recap
Acids
High \(H^+\) concentration. Sour, corrosive, pH < 7. Turns indicators red/pink.
Bases
Low \(H^+\) concentration. Bitter, slippery, pH > 7. Turns indicators blue/green/yellow.
Neutralization Equation
ACID + BASE
WATER + SALT
The Language of Color
🥬 Red Cabbage
Our first natural indicator. Wide range of colors (Rainbow) from 0 to 14.
🍵 Butterfly Pea
"Magic" tea. Reversible reaction. Changes from blue to pink in acid.
Observe the Shift
Why does it matter?
Agriculture
Soil pH determines if plants can absorb nutrients like nitrogen.
Oceans
Absorbing CO2 makes water acidic, harming coral reefs and shells.
Body
Your blood must stay strictly between 7.35 and 7.45 pH to survive.
Color Shift Assessment Quiz Color Shift Assessment
pH, Indicators, & Chemical Reactions
Name:
Date:
Section 1: Core Concepts
1. Which pH value represents a strong acid?
pH 2
pH 7
pH 9
pH 13
2. What specific pigment in red cabbage and butterfly pea flowers allows them to act as indicators?
Chlorophyll
Anthocyanin
Hemoglobin
Melanin
3. When an acid and a base are mixed together in equal strength, what is the resulting process called?
Evaporation
Neutralization
Solidification
Fermentation
Section 2: The pH Scale
Match the descriptions to the correct part of the pH scale by drawing a line.
Pure Lemon Juice
Distilled Water
Ammonia Cleaner
0 7 14
Strong Base
Neutral
Strong Acid
Section 3: Lab Analysis & Application
4. In the "Magic Tea" experiment, what happened to the color when you added baking soda to the pink (acidified) tea? Explain why this happened using the concept of pH balance.
5. Why do farmers and gardeners care about the pH of their soil? Give one specific example of what might happen if the soil is too acidic.
6. Challenge: Ocean acidification is caused by oceans absorbing too much CO2. Based on what you know about pH, how would this affect the concentration of hydrogen ions (\(H^+\)) in the water?
End of Unit Assessment • Color Shift Chemistry • 2026
