Concentration rule
Keeps the beaker honest by relating amount of solute to amount of liquid.
Solute amount 11 Solvent volume 1
Concept module
Concentration and Dilution
Use one beaker to separate how concentration changes when you add solvent from how it changes when you add more solute.
The simulation shows a beaker with dissolved particles, a concentration readout, and controls for solute amount and solvent volume. The mixture holds 11 units of solute in 1 units of solvent, giving a concentration of about 11. The beaker is crowded, so the same volume holds a lot of solute.
Interactive lab
Keep the stage, graph, and immediate control feedback in one working view.
Concentration and dilution
Keep solute amount and solution volume on the same beaker so dilution reads as spreading the same amount out rather than making it disappear.
Graphs
Switch graph views without breaking the live stage and time link.
Concentration vs solvent volume
One graph shows how concentration changes with solvent volume, and a second shows how concentration changes with solute amount.
solvent volume: 0.8 to 2.8concentration: 0 to 16
Concentration
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
Adding solvent lowers concentration even when the solute amount has not changed.
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.
Solute amount
11Changes how much dissolved material is present in the beaker.
Graph: Concentration vs solute amountOverlay: Density cueOverlay: Particle motion
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 beaker and the concentration graph in view together.
ObservationPrompt 1 of 2
Graph: Concentration vs solvent volume
Adding solvent lowers concentration even when the solute amount has not changed.
Control: Solvent volumeGraph: Concentration vs solvent volumeOverlay: Density cueOverlay: Amount-volume guideEquation
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
Density cue
Show how crowded or sparse the particle view is.
What to notice
- The same number of particles can look more dilute when they occupy more volume.
Why it matters
It makes concentration visible rather than purely numerical.
Control: Solute amountControl: Solvent volumeGraph: Concentration vs solvent volumeGraph: Concentration vs solute amountEquationEquation
Challenge mode
Use dilution honestly: do not smuggle in a different solute amount.
0/1 solved
ConditionCore
4 of 6 checks
Dilute without losing solute
Starting from a fairly crowded beaker, lower the concentration clearly while keeping the solute amount near the same starting value.
Graph-linkedGuided start
Matched
Open the Concentration vs solvent volume graph.
Concentration vs solvent volumeMatched
Keep the Density cue visible.
OnMatched
Keep the Amount-volume guide visible.
OnMatched
Keep solute amount between 10.5 and 11.5.
11Pending
Keep solvent volume between 1.8 and 2.6.
1Pending
Keep concentration between 3.6 and 5.6.
11The checklist updates from the live simulation state, active graph, overlays, inspect time, and compare setup.
The mixture holds 11 units of solute in 1 units of solvent, giving a concentration of about 11. The beaker is crowded, so the same volume holds a lot of solute.
Equation detailsDeeper interpretation, notes, and worked variable context.
Dilution story
Shows that dilution keeps the solute amount fixed while the liquid amount changes.
Solute amount 11 Solvent volume 1
Progress
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Current bench
Crowded beaker preset
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Stable links
1. Concentration and Dilution2. Acid-Base / pH Intuition
This concept is the track start.
Short explanation
What the system is doing
Concentration becomes easier to trust when the amount of solute and the amount of liquid stay visible together. This bench keeps one vessel, a concentration readout, and a particle view in the same frame so crowding and dilution do not turn into slogans.
The key distinction is that adding solvent changes concentration without adding solute, while adding solute changes concentration in a different way.
Key ideas
01Concentration is about how much solute is present in how much liquid.
02Dilution lowers concentration by increasing the amount of liquid while keeping the solute amount the same.
03Adding solute and adding solvent can both change concentration, but for different reasons.
Worked example
Read the full frozen walkthrough.
Frozen walkthrough
Use the current beaker state rather than a detached ratio problem.
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, how concentrated is the beaker?
Solute amount
11
Solvent volume
1
1. Read how much solute is present
The beaker currently holds 11 units of solute.
2. Read how much liquid is present
The same solute is spread through 1 units of solvent.
3. Read the concentration and density cue together
That gives a concentration of about 11, with roughly 40 visible particles in the beaker.
Current concentration
With less liquid in the beaker, the same solute occupies a tighter space and the concentration rises.
Common misconception
If the beaker looks fuller, that must mean there is more solute in it.
A fuller beaker can simply mean there is more solvent present.
Dilution changes concentration even when the solute amount does not change.
Mini challenge
Make the beaker clearly less concentrated without removing any solute.
Prediction prompt
Decide whether to change the amount of solute, the amount of solvent, or both before you try it.
Check your reasoning
You need to add solvent while keeping the solute amount fixed.
That is the cleanest way to model dilution rather than simply making a different mixture.
Quick test
Misconception check
Question 1 of 2
Answer from the live beaker story, not from a memorized slogan.
What is the cleanest description of dilution 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 a beaker with dissolved particles, a concentration readout, and controls for solute amount and solvent volume.
Graph summary
One graph shows how concentration changes with solvent volume, and a second shows how concentration changes with solute 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.
Use the same solution language to read pH and neutral balanceSolutions and pH
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.
Useful comparisonRates 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.
Useful comparisonThermodynamics
Ideal Gas Law and Kinetic Theory
Connect pressure, volume, temperature, and particle number on one bounded particle box, then read the same pressure changes back as changes in particle speed and wall-collision rate.