pH balance story
Keeps the pH number attached to the current acid-base balance.
Acid amount 4.2 Base amount 3.1
Concept module
Acid-Base / pH Intuition
Keep acid amount, base amount, water, and the pH strip visible together so acidity and basicity stay intuitive rather than memorized.
The simulation shows one acid-base vessel, a pH strip, and controls for acid amount, base amount, and water volume. The current mixture sits near pH 6.85 with acid share 55.45% and base share 44.55%. The mixture sits near neutral because the acid and base character are close together.
Interactive lab
Keep the stage, graph, and immediate control feedback in one working view.
Acid-base and pH intuition
Keep H+ character, OH- character, and the pH strip on one bounded bench so pH reads like a meaningful scale instead of a memorized number line.
Graphs
Switch graph views without breaking the live stage and time link.
pH vs acid amount
One graph shows pH against acid amount, and a second shows pH against base amount.
acid amount: 0 to 10pH: 0 to 14
pH
Controls
Adjust the live parameters and watch the bench respond.
Presets
Predict -> manipulate -> observe
Keep the active prompt next to the controls so each change has an immediate visible consequence.
ObservationPrompt 1 of 2
When acid character is stronger than base character, the pH strip should move below the neutral middle rather than feeling like a separate fact.
Equation map
See each variable before you move it.
Select a symbol to highlight the matching control and the graph or overlay it most directly changes.
Acid amount
4.2Increases the acid-side influence in the mixture.
Graph: pH vs acid amountOverlay: pH stripOverlay: Character bars
Equations in play
Choose an equation to sync the active symbol, control highlight, and related graph mapping.
More tools
Detailed noticing prompts, guided overlays, and challenge tasks stay available without taking over the main bench.
Hide
More tools
Detailed noticing prompts, guided overlays, and challenge tasks stay available without taking over the main bench.
What to notice
Keep the pH strip and the mixture character bars visible together.
ObservationPrompt 1 of 2
Graph: pH vs acid amount
When acid character is stronger than base character, the pH strip should move below the neutral middle rather than feeling like a separate fact.
Control: Acid amountGraph: pH vs acid amountOverlay: pH stripOverlay: Character barsEquation
Guided overlays
Focus one overlay at a time to see what it represents and what to notice in the live motion.
3 visible
Overlay focus
Character bars
Show the acid and base character bars together.
What to notice
- The pH strip and the mixture bars should agree about which side is stronger.
Why it matters
It keeps the pH number attached to a visible mixture story.
Control: Acid amountControl: Base amountControl: Water volumeGraph: pH vs acid amountGraph: pH vs base amountEquationEquationEquation
Challenge mode
Use the pH strip and the mixture bars together instead of chasing the number alone.
0/1 solved
TargetCore
4 of 6 checks
Land near neutral
Adjust the mixture until the pH sits near neutral while acid and base character stay visibly close together.
Graph-linkedGuided start
Matched
Open the pH vs acid amount graph.
pH vs acid amountMatched
Keep the pH strip visible.
OnMatched
Keep the Character bars visible.
OnMatched
Keep p h between 6.6 and 7.4.
6.85Pending
Keep acid share between 0.45 and 0.55.
0.55Pending
Keep base share between 0.45 and 0.55.
0.45The checklist updates from the live simulation state, active graph, overlays, inspect time, and compare setup.
The current mixture sits near pH 6.85 with acid share 55.45% and base share 44.55%. The mixture sits near neutral because the acid and base character are close together.
Equation detailsDeeper interpretation, notes, and worked variable context.
Water softening story
Shows why dilution can pull the mixture back toward the middle of the scale.
Water volume 1.4
Progress
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Let the live model runChange one real controlOpen What to notice
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Stable links
Starter track
Step 2 of 20 / 2 completeSolutions and pH
Earlier steps still set up Acid-Base / pH Intuition.
1. Concentration and Dilution2. Acid-Base / pH Intuition
Previous step: Concentration and Dilution.
Short explanation
What the system is doing
Acid-base intuition becomes easier to trust when the pH scale and the mixture character stay visible together. This bench keeps acid amount, base amount, water volume, and the current pH in one bounded scene.
The point is not fake precision. The goal is to see why more acid pushes the mixture one way, more base pushes it the other way, and extra water softens both influences toward the middle.
Key ideas
01pH is a scale that tracks whether acid character or base character is currently stronger.
02Adding acid and adding base push the mixture in opposite directions on the same pH strip.
03Adding more water softens the strength of both sides and can move the mixture back toward neutral.
Worked example
Read the full frozen walkthrough.
Frozen walkthrough
Use the current acid-base bench instead of a detached number-line exercise.
Live worked examples are available on Premium. You can still read the full frozen walkthrough on the free tier.
View plansFrozen valuesUsing frozen parameters
For the current mixture, what does the pH say about acid and base character?
Acid amount
4.2
Base amount
3.1
Water volume
1.4
1. Read the current mixture amounts
The bench currently has acid amount 4.2, base amount 3.1, and water volume 1.4.
2. Compare the two mixture characters
That gives acid character 4 and base character 3.21.
3. Read the pH scale together with the mixture bars
The resulting pH is about 6.85, with acid share 55.45% and base share 44.55%.
Current pH reading
The acid and base character are close here, so the pH scale stays near neutral rather than leaning sharply to one side.
Common misconception
A pH number is just a memorized label, so the particle picture does not add much.
The pH number summarizes which character is stronger in the mixture right now.
The particle and bar cues help show why the scale moves instead of treating pH like an isolated fact.
Mini challenge
Move the mixture toward neutral without simply removing the stronger side completely.
Prediction prompt
Decide whether a balancing addition or extra water is the cleaner move before you try it.
Check your reasoning
You can move toward neutral by adding the opposite character or by diluting the mixture with more water.
Both actions soften the imbalance, but for different reasons.
Quick test
Reasoning
Question 1 of 2
Answer from the live pH and mixture cues.
What does the current pH most directly summarize on this bench?
Choose one answer to reveal feedback, then test the idea in the live system if a guided example is available.
Accessible description
The simulation shows one acid-base vessel, a pH strip, and controls for acid amount, base amount, and water volume.
Graph summary
One graph shows pH against acid amount, and a second shows pH against base amount.
Read next
Keep moving through the concept map.
These suggestions come from the concept registry, so the reason label reflects either curated guidance or the fallback progression logic.
Carry the chemistry branch into successful collisions and reaction changeRates and Equilibrium
Reaction Rate / Collision Theory
Keep one chemistry box visible so temperature, concentration, activation threshold, and catalysts can be read as changes in successful collisions instead of chemistry slogans.
Next in How crowded the solution isSolutions and pH
Concentration and Dilution
Use one beaker to separate how concentration changes when you add solvent from how it changes when you add more solute.
Useful comparisonRates and Equilibrium
Dynamic Equilibrium / Le Chatelier's Principle
Watch a reversible chemistry bench keep changing microscopically while the mixture settles toward a new balance after each disturbance.