RP 11 - Identifying Transition Metal Ions

Question 1

How do transition metals undergo precipitation reactions?

Answer 1

They react with OH- ions to form metal hydroxide precipitate

Question 2

What can be reacted with transition metals for a precipitation reaction to occur?

Answer 2

• Aqueous NaOH
• Ammonia

Question 3

What is the first and second test that can be carried out to identify transition metal ions?

Answer 3

• First test:
1. Place 10 drops of each solution in a test tube.
2. Add NaOH solution drop-by-drop to each until in excess. Record any observations
3. Stand in a beaker of hot water for 10 minutes
• Second test:
1. Add about 10 drops of each solution into a different test tube with Na2CO3 (aq). Shake and record observations

Question 4

There’s a yellow solution that underwent the first and second test that can be carried out to identify transition metal ions. After adding NaOH it was an orange/brown precipitate; on standing in hot water there was no visible change; after the second test it was an orange/brown precipitate and there was effervescence. What were the ions present in the solution?

Answer 4

Iron (III) ions

Question 5

There’s a light blue solution that underwent the first and second test that can be carried out to identify transition metal ions. After adding NaOH it was a deep blue precipitate; on standing in hot water there was no visible change; after the second test it was a blue/green precipitate. What were the ions present in the solution?

Answer 5

Copper (II) ions

Question 6

There’s a pale green solution that underwent the first and second test that can be carried out to identify transition metal ions. After adding NaOH it was a grey/green precipitate; on standing in hot water there was no visible change; after the second test it was a grey/green precipitate. What were the ions present in the solution?

Answer 6

Iron (II) ions

Question 7

For iron (III) ions, what colour is the solution? What are the observations when it undergoes the first and second test that can be carried out to identify transition metal ions?

Answer 7

It’s initially a yellow solution. After adding NaOH (from the first test), it’s an orange/brown precipitate. On standing in hot water (from the first test), there’s no visible change. After the second test, it’s an orange/brown precipitate and there’s effervescence

Question 8

For copper (II) ions, what colour is the solution? What are the observations when it undergoes the first and second test that can be carried out to identify transition metal ions?

Answer 8

It’s initially a light blue solution. After adding NaOH (from the first test), it’s a deep blue precipitate. On standing in hot water (from the first test), there’s no visible change. After the second test, it’s a blue/green precipitate

Question 9

For iron (II) ions, what colour is the solution? What are the observations when it undergoes the first and second test that can be carried out to identify transition metal ions?

Answer 9

It’s initially a pale green solution. After adding NaOH (from the first test), it’s a grey/green precipitate. On standing in hot water (from the first test), there’s no visible change. After the second test, it’s a grey/green precipitate