MISSION 04 · CHEMISTRY DISCOVERY
Two clear liquids look alike. Can your test strips identify the hidden base?
2 · Follow the Colour Clues
Your new skill: Identify known acid, water and base samples from evidence.
Revisit the skill you will reuse: Previous main-path mission
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.
This spoon measures a repeatable amount of powder so our comparisons use the same amount.
Look for: Find the kit's supplied measure and its labelled amount. A level spoon is flat across the top.
Before using it: Use the approved kit measure, not a random kitchen spoon. Powder amount and spoon size must match the kit batch instructions.
Your turn: Show the difference between level and heaped using an empty spoon and a drawing.
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.
Citric acid is our labelled acidic material. Dissolved in water it can change an indicator's colour and react with baking soda.
Look for: Find the sealed container with its correct label. Similar-looking powders are not interchangeable.
Before using it: Use only the stated amount, goggles and adult supervision. Experiment materials are not food. Keep away from eyes and mouth.
Your turn: Read the label with a grown-up before opening it.
Baking soda is our labelled mild base. With citric acid and water, the reaction releases carbon dioxide gas.
Look for: Find the container labelled baking soda, not baking powder.
Before using it: Use only the stated amount with adult supervision. Never close a fizzing mixture in a sealed container.
Your turn: Predict where bubbles can escape safely in the open experiment.
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 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. Calibrated kit measuring spoon. This spoon measures a repeatable amount of powder so our comparisons use the same amount. Find the kit's supplied measure and its labelled amount. A level spoon is flat across the top. Use the approved kit measure, not a random kitchen spoon. Powder amount and spoon size must match the kit batch instructions. 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. Citric acid. Citric acid is our labelled acidic material. Dissolved in water it can change an indicator's colour and react with baking soda. Find the sealed container with its correct label. Similar-looking powders are not interchangeable. Use only the stated amount, goggles and adult supervision. Experiment materials are not food. Keep away from eyes and mouth. Baking soda. Baking soda is our labelled mild base. With citric acid and water, the reaction releases carbon dioxide gas. Find the container labelled baking soda, not baking powder. Use only the stated amount with adult supervision. Never close a fizzing mixture in a sealed container. 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. 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. The adult prepares or labels the mystery tubes. Use a fresh strip for every sample.
YOUR REWARD
PREDICT BEFORE YOU BEGIN
Which evidence would be stronger: one indicator result or two different indicator results?
YOUR CHALLENGE
NEW POWER-UP
Identify known acid, water and base samples from evidence.
You have just practised use a small indicator mark to detect acidity. Now: identify known acid, water and base samples from evidence.
BUILD PATH
STEP 1 OF 8
Ask the adult to prepare and label the three tubes A, B and C without telling you which is which.
A video demonstration will appear here when it is ready. You can follow the written step now.
Ask the adult to prepare and label the three tubes A, B and C without telling you which is which.
WHAT'S REALLY HAPPENING?
Acids and bases can both look like plain water. Indicators provide evidence that our eyes cannot see. A basic solution usually changes red litmus toward blue and gives a basic-range colour on the supplied pH chart.
Testing unknown samples is a basic laboratory skill. Scientists use several pieces of evidence before making a conclusion.
FAIR-TEST CHALLENGE
Repeat one sample twice with fresh strips. If the two results disagree, check your dropper and procedure rather than choosing the result you prefer.
WHEN IT DOESN'T WORK YET
WHAT YOU SEE LIKELY REASON TRY THIS FIRST All samples give the same result The dropper may have carried material between tubes. Use fresh strips and rinse the dropper completely between samples. Colours are weak The solutions may be too dilute or strips may be wet. Use fresh dry strips and the stated quantities. You are unsure which colour matches Lighting may change how colours look. Compare under bright white light beside the supplied chart.
CLEAN, RESET AND STORE
Discard all used strips. Pour the small solutions into the sink with plenty of water. Rinse and dry the tubes, stand tools and dropper.
NEXT SKILL
Read a coarse chart and compare sample colours.