Transition elements

Question 1

What are the colours of different transition metal compounds?

Answer 1

• Copper compounds are often blue.
• Iron(II) compounds are often pale green.
• Iron(III) compounds are often orange/brown.

Question 2

Transition metals as catalysts

Answer 2

• Iron is used in the Haber process to make ammonia, which is used in fertilisers.
• Nickel is used in the manufacture of margarine to harden oil.( ͡° ͜ʖ ͡°)

Question 3

What is a catalyst?

Answer 3

A catalyst is a chemical that speeds up a reaction but it is not changed or used up by the reaction

Question 4

What happens when metal carbonate is heated?

Answer 4

It undergoes thermal decomposition to form metal oxide and carbon dioxide.

Question 5

Copper Thermal Decomposition

Answer 5

CuCO₃ ⇒ CuO + CO₂

Question 6

Iron Thermal Decomposition

Answer 6

FeCO₃ ⇒ FeO + CO₂

Question 7

Manganese Thermal Decomposition

Answer 7

MnCO₃ ⇒ MnO + CO₂

Question 8

Zinc Thermal Decomposition

Answer 8

ZnCO₃ ⇒ ZnO + CO₂

Question 9

What happens when sodium hydroxide reacts with a transition metal?

Answer 9

• A solid called metal hydroxide precipitates form.
  
  • Cu2+ ions form a blue solid.
  • Fe2+ ions form a grey/green solid.
  • Fe3+ ions form a orange/brown gelatinous solid.

Question 10

Precipitation reaction of copper ions.

Answer 10

Fe²⁺ + 2OH^- ⇒ Cu(OH)₂

Question 11

Precipitation reaction of iron(II) and iron (III) ions.

Answer 11

Fe²⁺ + 2OH^- ⇒ Fe(OH)₂

Fe³⁺ + 3OH^- ⇒ Fe(OH)3