1. Chemical testing for Ions
OCR SCIENCE – UNIT 1 BEST PRACTICE
Chemical testing for Ions
Prior learning
Chemicals can react together and change colour
Key words
React, precipitate, colour change, identify, Cations, Anions

2. OCR SCIENCE – UNIT 1 BEST PRACTICE
I am learning to: identify cations and anions in different solutions by their colour change
I will be successful if I can:
Describe the term cation and anion and explain the test to be carried out
Carry out a practical activity safely (having completed a risk assessment) to confirm the presence of different cations an anions
Complete a table to show results of practical tests
Conclude, Evaluate and comment on reliability of the test
Outcome: I can identify unknown ions in a given solution.
TO ACHIEVE A MERIT:
Add DETAIL to your report by explaining what is happening in each step using the guidance sheets.
Relate the results of the test back to the scenario of students becoming ill having played on the playing fields.
Complete an aim, prediction and method in handwritten form to add to your testing notes.
Any of these can be completed at home or with Ms C’s help at break, lunch or after school.

3. Introduction: what are ions?
I am learning to:identify cations and anions in different solutions by their colour change
Introduction: what are ions?
Ions are charged particles.
Positively charged particles are called CATIONS (because they are attracted to the negative electrode called the cathode which are usually metals)
Negative Ions are called ANIONS because they are attracted to the anode these are usually non-metals
CuSO4
Cu 2+
SO4-

4. I am learning to:identify cations and anions in different solutions by their colour change
Reference
Ion
Test
Result
Chloride
Add Silver nitrate Solution
White precipitate
Sulphate
Add acidified Barium chloride solution
Carbonate
Add dilute acid and test gas with limewater
Milky white precipitate
Copper (Cu++)
Add Sodium hydroxide solution
Blue precipitate
Iron
Brown precipitate

5. I am learning to:identify cations and anions in different solutions by their colour change
Reference
Copper Cations
Sodium hydroxide
Iron Cations

6. I am learning to:identify cations and anions in different solutions by their colour change
Reference
Carbonate Anions
Acid
Chloride Anions
Silver Nitrate

7. I am learning to:identify cations and anions in different solutions by their colour change
Reference
Sulphate Anions
Barium Chloride

8. I am learning to:identify cations and anions in different solutions by their colour change
Risk Assessment
Department: Science Room Number: R4
Brief summary of activity: Chemical tests for chlorides, sulphates and carbonates
List hazardous procedures and the hazards) relating to them
Procedure
Using squirt bottles & glass
Hazard
Chemical in eye, broken glass cuts
List the substances hazardous to health and the hazards) relating to them
Substance
chemicals
Irritant, harmful and corrosive
Risk and Safety phrases
Wear goggles
List who might be exposed to the hazard substance(s).
(e.g. staff, students, visitors, cleaners)
Staff & pupils
Assessing the level of risk
How severe is any injury or health effect likely to be? Medium
How likely is exposure to the hazard? Medium
High Medium Low
Emergency Procedures
(first aid actions, fire actions, spill action)
Wash hands under cold water
Wipe up any spills
Brush up broken glass and put in glass bin
Disposal requirements
Technician to dispose of waste in prep room
Date: Name: Signature:
What is the overall level of risk? (Tick appropriate box – if risk is high further steps must be taken to
minimum the risk of the procedure) x

9. I am learning to:identify cations and anions in different solutions by their colour change
Results
Test
Samples
Add Silver nitrate solution
Add acidified Barium chloride solution
Add dilute acid and bubble gas through limewater
Add Sodium hydroxide
Sample ion A B C
Soil
Water

10. I am learning to:identify cations and anions in different solutions by their colour change
Results
Test
Samples 1 2 3
water
soil
Add Silver nitrate solution
yes X
Yes
Add acidified Barium chloride solution
Add dilute acid and bubble gas through limewater
Add Sodium hydroxide x
Sample ion
chloride
sulphate
copper
Iron

11. Conclusion of findings
I am learning to:identify cations and anions in different solutions by their colour change
Conclusion of findings
Conclusion of findings:
____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

12. I am learning to:identify cations and anions in different solutions by their colour change
Reliability
Do qualitative tests tell you how much of a substance is present?
No, just if the substance is present
If the test substance is a mixture will one get clear results?
No more than one result may show
3. Will the tests work if the substance is insoluble? no
4. Is there an amount of substance needed to get a positive test?
Small amounts of each substance should work
5. Can your test substances be contaminated?
Yes if clean pipettes are not used

13. Complete the associated worksheet on Chemical tests
I am learning to: view samples using a microscope and test samples for metals using flame tests
HOMEWORK
Complete the associated worksheet on Chemical tests
Approx. 10mins

14. OCR SCIENCE – UNIT 1 BEST PRACTICE
I am learning to: identify cations and anions in different solutions by their colour change
I will be successful if I can:
Describe the term cation and anion
Carry out a practical activity safely to confirm the presence of different cations an anions
Complete a table to show results of practical tests
Outcome: I can identify unknown ions in a given solution.

15. Summary – draw the colour changes of each test on plain paper
I am learning to:identify cations and anions in different solutions by their colour change
Summary – draw the colour changes of each test on plain paper
Copper Cations
Sodium hydroxide
Iron Cations