Test four mystery materials, mix a solid with a liquid, then test what comes back to find out which mixtures made a brand new substance and which ones just mixed together without reacting.
How do I explore?
- On the Test Bench, pick a sample from the shelf, choose a test (Density, Heating, Solubility, Flame, or Odor), then press Run Test.
- On the Mixing Station, choose one solid (A or B) and one liquid (C or D), then press Mix and watch closely.
- When a mix finishes, press Send for Separation. The samples that come back appear on your shelf with new letters, so you can test them too.
What should I do/notice?
- First test all four starting materials and note each property.
- After a mix, compare the products with the starting materials. Do the properties match a starting material, or are they new?
- Watch for signs of a new substance, like fizzing gas or a set of properties that does not match any starting material.
Accessibility
- Press Tab to move through the tabs, test buttons, sample shelf, and apparatus. Press Enter or Space to choose.
- On the Test Bench, the Arrow keys move between the shelf samples and the apparatus.
- Press Escape to put a carried sample back on the shelf.
Test four mystery materials, mix a solid with a liquid, then test what comes back to find out which mixtures made a brand new substance and which ones just mixed together without reacting.
Standards
MS-PS1-2 Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
Design intent
- Characteristic properties (density, melting or boiling point, solubility, flammability, and odor) identify a substance. If a product's properties match a starting material, no new substance formed.
- The letter names are hidden so students cannot shortcut by recognizing a familiar chemical. They have to compare measured properties.
- One reacting pair and three non-reacting pairs give both positive and negative cases of chemical change, including a pair where nothing visible happens.
Discussion prompts
- Which mixtures made a new substance? What property evidence supports that?
- One pair produced a gas. How can you tell the gas is not one of the starting materials?
- After a mix, is the recovered solid new or one of the reactants? How do you know?
Model details
The two solids are zinc granules and glucose; the two liquids are dilute hydrochloric acid and water. Only zinc plus dilute acid reacts, producing a new solid (zinc chloride) and hydrogen gas. Each substance carries its real measured properties, so a teacher can work out the letter mapping quickly with a reference table.
- The dilute acid is treated as one liquid substance. Liquids get a boiling point only and solids get a melting point only, matching what a school hot plate can show.
- The gas sample cannot be weighed or heated at this bench, so its density and melting or boiling point stay unavailable.
- Flammability is tested by state of matter: solids in the flame with tongs, a few drops of a liquid with a splint, and a gas with the lit-splint pop test. Organic material burns; the metal and its salt do not.
- Heating is time-compressed; real melting and boiling take far longer.
- Separation of a mixture happens off stage, and leftover excess liquid is not modeled.
- The reacting amounts are fixed so the solid is fully consumed.