OPTIONAL CHALLENGE 02 · CHEMISTRY DISCOVERY
Soap touches water every day. What chemical clue will its solution reveal?
Optional · Try Another Angle
Your new skill: Extend a main-path idea without making the course longer.
Match the names to your parts before you build. New parts appear when you first need them. You can point, say the name or show a grown-up.
A dropper moves a small amount of liquid, one drop at a time.
Look for: Find its squeeze bulb and narrow tip.
Before using it: Squeeze before dipping, release to draw liquid, then press gently. Rinse between samples. Never mouth-pipette. Drop size can vary.
Your turn: Practise three separate drops of clean water into a tray.
A tube holds a small sample. The stand helps keep tubes upright while we compare them.
Look for: Find the narrow containers and matching holes in the stand.
Before using it: Label samples before filling. Keep them open and stable; never seal a fizzing reaction.
Your turn: Place two empty tubes in the stand and label them A and B.
A mixing stick moves liquid and powder together so we can compare how mixing affects a result.
Look for: Find the clean stirrer named in the materials.
Before using it: Use a clean stick for each sample, or rinse and dry between samples. Never taste it.
Your turn: Rehearse a gentle stir in an empty container without splashing.
These papers give colour clues about acidity. Litmus tells us acid or base clues; pH paper is compared with its matching colour chart.
Look for: Find red or blue litmus, or pH strips with their supplied chart. They are not interchangeable.
Before using it: Use a fresh piece for each sample and read at the stated time. A colour estimate is not an exact laboratory pH or a food safety test.
Your turn: Match an unused strip to its packet and chart.
A little dish soap changes how the surface of water behaves and can help trap bubbles as foam.
Look for: Use ordinary dish soap named by the mission, from home.
Before using it: Use tiny amounts only, keep away from eyes and do not substitute bleach or cleaning chemicals.
Your turn: Predict whether plain water and soapy water will behave the same.
A video demonstration will appear here when it is ready. You can follow the written step now.
Before we build, match these names to the parts in front of you. Dropper. A dropper moves a small amount of liquid, one drop at a time. Find its squeeze bulb and narrow tip. Squeeze before dipping, release to draw liquid, then press gently. Rinse between samples. Never mouth-pipette. Drop size can vary. Test tube and stand. A tube holds a small sample. The stand helps keep tubes upright while we compare them. Find the narrow containers and matching holes in the stand. Label samples before filling. Keep them open and stable; never seal a fizzing reaction. Mixing stick. A mixing stick moves liquid and powder together so we can compare how mixing affects a result. Find the clean stirrer named in the materials. Use a clean stick for each sample, or rinse and dry between samples. Never taste it. Litmus and pH paper. These papers give colour clues about acidity. Litmus tells us acid or base clues; pH paper is compared with its matching colour chart. Find red or blue litmus, or pH strips with their supplied chart. They are not interchangeable. Use a fresh piece for each sample and read at the stated time. A colour estimate is not an exact laboratory pH or a food safety test. Dish soap. A little dish soap changes how the surface of water behaves and can help trap bubbles as foam. Use ordinary dish soap named by the mission, from home. Use tiny amounts only, keep away from eyes and do not substitute bleach or cleaning chemicals. Pause and point to the part that will do the main job in this mission. If it is missing or looks different, ask a grown-up before building.
WHAT YOU'LL USE
Kit list: match the named parts to your box and its component cards. Home list: gather these before starting; some may also be supplied in your kit. Reuse components between missions. Stop and ask a grown-up if an essential part or label is missing.
BEFORE YOU BUILD
Wear goggles. Do not touch your eyes after handling soap solution. Never taste a sample, even if the ingredient is used at home.
YOUR REWARD
PREDICT BEFORE YOU BEGIN
Will two drops of soap make a result closer to acid, neutral or base?
YOUR CHALLENGE
NEW POWER-UP
Use a control sample and avoid confusing pH with overall product safety.
You can use pH paper and control small additions. Now you will compare a real-life sample with plain water.
BUILD PATH
STEP 1 OF 8
Label the tubes WATER and SOAP.
A video demonstration will appear here when it is ready. You can follow the written step now.
Label the tubes WATER and SOAP.
WHAT'S REALLY HAPPENING?
Many soaps are mildly basic, but the exact result depends on the product and concentration. pH tells us about acidity or basicity in a water-based sample. It does not tell us every ingredient, whether something is clean, or whether it is safe to consume.
Product developers test pH to help design shampoos, cleaners, cosmetics and water-treatment products.
FAIR-TEST CHALLENGE
Test soap solutions made with 1 drop and 3 drops in the same amount of water. Keep everything else the same.
WHEN IT DOESN'T WORK YET
WHAT YOU SEE LIKELY REASON TRY THIS FIRST Water and soap give identical colours The soap solution may be very dilute or the paper range broad. Try the approved 3-drop comparison and use fresh paper. The water result is unusual The water or tools may contain residue. Use freshly rinsed, dry tools and clean water. The dropper fills with foam The solution was stirred too vigorously. Wait for foam to settle and collect liquid below the bubbles.
CLEAN, RESET AND STORE
Pour both samples down the sink, rinse all tools, wash hands and dry the tube stand area.
NEXT SKILL
Next you will leave pH behind and use glitter to make invisible liquid motion visible.