5.3 TRANSITION METALS

Question 1

State the two types of precipitation reactions transition metals can undergo

Answer 1

1) Sodium hydroxide + transition metal
2) Ammonia + transition metal

Question 2

State the colour of Cu2+ / Copper solution

Answer 2

• Blue

Question 3

State the colour of Fe2+ / Iron(II) solution

Answer 3

• Green

Question 4

State the colour of Fe3+ / Iron(III) solution

Answer 4

• Yellow

Question 5

State the colour of Mn2+ / Manganese solution

Answer 5

• Pink

Question 6

State the colour of Co2+ / Cobalt solution

Answer 6

• Pink

Question 7

State the colour of Cr3+ / Chronium solution

Answer 7

• Green

Question 8

State the observation of Cu2+ with dropwise then excess aqueous NaOH/ Sodium hydroxide

Answer 8

• Blue precipitate forms
• no change with excess NaOH

Question 9

State the observation of Fe2+ with dropwise then excess aqueous NaOH/ Sodium hydroxide

Answer 9

• Green precipitate forms
• No change with excess NaOH

Question 10

State the observation of Fe3+ with dropwise then excess aqueous NaOH/ Sodium hydroxide

Answer 10

• Brown precipitate forms
• No change with excess NaOH

Question 11

State the observation of Mn2+ with dropwise then excess aqueous NaOH/ Sodium hydroxide

Answer 11

• Brown precipitate forms
• No change with excess NaOH

Question 12

State the observation of Co2+ with dropwise then excess aqueous NaOH/ Sodium hydroxide

Answer 12

• Blue precipitate forms
• No change with excess NaOH

Question 13

State the observation of Cr3+ with dropwise then excess aqueous NaOH/ Sodium hydroxide

Answer 13

• Green precipitate forms
• Precipitate dissolves in excess NaOH

Question 14

State the observation of Cu2+ with dropwise then excess aqueous NH3/Ammonia

Answer 14

• Blue precipitate forms
• Deep blue solution forms with excess NH3

Question 15

State the observation of Fe2+ with dropwise then excess aqueous NH3/Ammonia

Answer 15

• Green precipitate forms
• No change with excess NH3

Question 16

State the observation of Fe3+ with dropwise then excess aqueous NH3/Ammonia

Answer 16

• Brown precipitate forms
• No change with excess NH3

Question 17

State the observation of Mn2+ with dropwise then excess aqueous NH3/Ammonia

Answer 17

• Brown precipitate forms
• No change with excess NH3

Question 18

State the observation of Co2+ with dropwise then excess aqueous NH3/Ammonia

Answer 18

• Blue precipitate forms
• No change with excess NH3

Question 19

State the observation of Cr3+ with dropwise then excess aqueous NH3/Ammonia

Answer 19

• Green precipitate forms
• Purple solution forms with excess NH3

Question 20

Define transition element

Answer 20

• A d-block element that has an incomplete d-sub-shell when a stable ion

Question 21

State the two elements are not classed as a transition element/metal

Answer 21

• Zinc Zn2+
• Scandium Sc3+

Question 22

State the electron configuration to explain why scandium 3+ is not a transition element/metal

Answer 22

• Scandium’s d-orbital is empty

Question 23

State the electron configuration to explain why zinc 2+ is not a transition element/metal

Answer 23

• Zinc’s d-orbital is full/complete

Question 24

Give two examples of transition metals as catalysts

Answer 24

1) MnO2 catalyses the decompostion of H202
2) Cu2+ catalyses the reaction of Zn with acids

Question 25

Give **two** examples of **transition elements** with **variable oxidation states**

Answer 25

1) **Fe2+** and **Fe3+** 2) **Cr2+** and **Cr3+** and **Cr6+**

Question 26

State an **advantage** and **disadvantage** of using **transition metals** as **catalysts**

Answer 26

- **Reduces energy usage** which **improves profits** - However, they are **toxic**

Question 27

Define **complex**

Answer 27

- A **central metal ion** surrounded by **ligands**

Question 28

Define **ligand**

Answer 28

- An **atom**, **ion** or **molecule** which can **donate** a **lone pair** of **electrons**

Question 29

State the type of **bonding** used in **complex** formation

Answer 29

- **Co-ordinate/dative covalent**

Question 30

Define **co-ordination number**

Answer 30

- The number of **co-ordinate bonds** formed to a **central metal ion**

Question 31

Define **bidentate ligand**

Answer 31

- A **ligand** that donates **two electron pairs** to a **metal ion** to form **two co-ordinate bonds** with the **metal ion**

Question 32

Define **monodetate ligand**

Answer 32

- A **ligand** that donates **one electron pair** to a **metal ion** to form **one co-ordinate bond** with the **metal ion**

Question 33

Draw the **two optical isomers** of the **complex ion ethandioate** and state the **co-ordinate number**

Answer 33

- **6**

Question 34

Draw the **two optical isomers** of the **complex ion** and state the **co-ordinate number**

Answer 34

- **6**

Question 35

State what is required for **cis-trans isomerism** in **square planar complexes**

Answer 35

- **Four ligands** where **two** are the **same** and the **other two** are the **same**

Question 36

State what is required for **cis-trans isomerism** in **octahedral complexes**

Answer 36

- **Six ligands** where **four** are the **same** and the **other two** are the **same**

Question 37

State what is required for **optical isomerism** in **octahedral complexes**

Answer 37

- **Three bidentate ligands**

Question 38

Describe the **advantages** and **disadvantages** of the use of **cisplatin**

Answer 38

- **Anti-cancer drug** used in **chemotherapy** - **Binds** to the **DNA** in **cancer cells** to **prevent division** and stop cancer - However can cause **hairloss**, **sickness** and **fatigue** if it **binds** to **healthy cells**

Question 39

Define **ligand substitution**

Answer 39

- A reaction where **one ligand** is **substituted** for **another ligand** in a **complex ion**

Question 40

Explain the importance of **iron** in **haemoglobin** in terms of **ligand substitution**

Answer 40

- **O₂** is a **ligand** that **datively/co-ordinately** bonds with **Fe²⁺** so that **oxygen** can be carried in the **blood** - When required, **O₂** is **released**

Question 41

Explain why **carbon monoxide** is **toxic** in terms of **ligand substitution**

Answer 41

- **CO** is a **ligand** that **datively/co-ordinately** bonds with **Fe²⁺** in **haemoglobin** - These are **stronger** than the ones **O₂** forms with **Fe²⁺** in haemoglobin - This **prevents O₂** from bonding to it

Question 42

State the **three** typical reaction of **transition metals**

Answer 42

1) **Percipitation** 2) **Ligand substitution** 3) **Redox**

Question 43

Draw out all the reactions of **iron** as a **transition metal**

Answer 43

Question 44

Draw out all the reactions of **copper** as a **transition metal**

Answer 44

Question 45

Draw out all the reactions of **chronium** as a **transition metal**

Answer 45

Question 46

Draw out all the reactions of **cobalt** as a **transition metal**

Answer 46

Question 47

Draw out all the reactions of **manganese** as a **transition metal**

Answer 47

Question 48

Test for **Cu²⁺** ions

Answer 48

- **Cu²⁺** is a **blue solution** - **Dropwise NH₃** or **OH⁻** produces a **blue percipitate** - **Excess NH₃ dissolves** the **blue percipitate** to form a **blue solution** - No change with **excess OH⁻**

Question 49

Test for **Fe²⁺** ions

Answer 49

- **Fe²⁺** is a **green solution** - **Dropwise NH₃** or **OH⁻** produces a **green percipitate** - No change with **excess NH₃** - No change with **excess OH⁻**

Question 50

Test for **Fe³⁺** ions

Answer 50

- **Fe³⁺** is a **yellow solution** - **Dropwise NH₃** or **OH⁻** produces a **brown percipitate** - No change with **excess NH₃** - No change with **excess OH⁻**

Question 51

Test for **Mn²⁺** ions

Answer 51

- **Mn²⁺** is a **pink solution** - **Dropwise NH₃** or **OH⁻** produces a **brown percipitate** - No change with **excess NH₃** - No change with **excess OH⁻**

Question 52

Test for **Cr³⁺** ions

Answer 52

- **Cr³⁺** is a **green solution** - **Dropwise NH₃** or **OH⁻** produces a **green percipitate** - **Excess NH₃ dissolves** the **green percipitate** to form a **purple solution** - **Excess OH⁻ dissolves** the **green percipitate** to form a **green solution**

Question 53

Test for **NH₄⁺**

Answer 53

- Add **NaOH** and **gentle warming** - **Distinctive ammonia** gas **smell** will turn **red litmus** paper into **blue**

Question 54

Test for **CO₃²⁻**

Answer 54

- Add **strong acid** - Produces **carbon dioxide gas** which turns **limewater cloudy**

Question 55

Test for **SO₄²⁻**

Answer 55

- Add **barium chloride** - A **white percipitate** of **barium sulfate** forms

Question 56

Test for **Cl⁻**,**Br⁻**,**I⁻** ions

Answer 56

Question 57

State in which order **4s** **electrons** are **added** and **removed**

Answer 57

- **added first** and **removed first**