Required Practical: Identifying Ions (OCR GCSE Chemistry A (Gateway Science Suite)): Revision Notes

This practical involves using a series of chemical tests to identify the ions present in various solutions. The tests include flame tests and test tube reactions.

Flame Test

1. Weigh Out the Sample: Measure 2 g of a metal oxide powder containing an unknown metal ion.
2. Perform the Flame Test:

• Use a splint to scoop up a small amount of the metal oxide powder.
• Place the splint with the powder into the flame of a Bunsen burner.
• Observe and record the colour of the flame.
• Use the flame colour to identify the metal ion present.

Test Tube Reactions 3. Prepare Samples:

• Set up 5 beakers, each containing a solution with an unknown ion.
• From each beaker, take 5 samples and add each to a separate test tube.

4. Perform Reactions:

• Test 1: Add an equal volume of sodium hydroxide $(NaOH)$to the first test tube.
• Test 2: Add an excess volume of sodium hydroxide (NaOH) to the second test tube.
• Test 3: Add dilute sulfuric acid $\ce{H2​SO4}$to the third test tube, collect any gas given off, and bubble it through lime water.
• Test 4: Add a solution of silver nitrate $\ce{(AgNO3​)}$ to the fourth test tube to test for halide ions.
• Test 5: Add a solution of barium chloride $\ce{(BaCl2​)}$ to the fifth test tube to test for sulphate ions.