Identifying substances · Grade 10
Blood-red test for iron(III)
ChemAI · Worksheet
NameClassDate
Aim
Thiocyanate ions find even a trace of Fe³⁺.
Before you start: what do you predict will happen? Why?
What you do
| Step | What I observed | |
|---|---|---|
| 1 | Add potassium thiocyanate to tube 1 (iron(III) chloride). | |
| 2 | Add it to tube 2 (copper(II) sulfate) as a control. | |
| 3 | Tube 3 is almost colourless — but it contains a trace of Fe³⁺. Test it. |
Questions
- Write a word or symbol equation for one reaction you observed.
- Explain your most important observation using particles, ions or energy.
- Was your prediction right? What would you change to get a more reliable result?