2.5 - Transition Metals 3

Question 1

Catalyst for Contact Process?

Answer 1

V₂O₅(s)

Question 2

Equations for: Contact Process

Answer 2

V₂O₅(s) + SO₂(g) |> SO₃(g) + V₂O₄(s)
V₂O₄(s) + ½O₂(g) |> V₂O₅(s)

Overall: SO₂(g) + ½O₂(g) |> SO₃(g)

Question 3

Equations for reaction between S₂O₈²⁻ & I⁻?

Answer 3

2Fe²⁺(aq) + S₂O₈²⁻(aq) |> 2Fe³⁺(aq) + 2SO₄²⁻(aq)

2Fe³⁺(aq) + 2I⁻(aq) |> 2Fe²⁺(aq) + I₂(aq)

Question 4

Intermediate for reaction between S₂O₈²⁻ & I⁻?

Answer 4

Fe³⁺(aq)

or Fe²⁺(aq) if Fe³⁺(aq) is catalyst

Question 5

Catalyst for reaction between S₂O₈²⁻ & I⁻?

Answer 5

Fe²⁺(aq)

or Fe³⁺(aq)

Question 6

How does a Heterogeneous Catalyst work?

Answer 6

Reactants are adsorbed to active sites on catalyst surface

Question 7

How does Mn²⁺ Autocatalyse the reaction between MnO₄⁻ & C₂O₄²⁻?

Answer 7

Step 1: rate v. slow whilst some Mn²⁺ is formed
2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ |> 2Mn²⁺ + 8H₂O + 10CO₂

Step 2: Mn²⁺ & MnO₄⁻ react
4Mn²⁺ + MnO₄⁻ + 8H⁺ |> 5Mn³⁺ + 4H₂O

Step 3: Mn³⁺ & C₂O₄²⁻ react
2Mn³⁺ + C₂O₄²⁻ |> 2Mn²⁺ + 2CO₂

Question 8

Define: Catalyst Poisoning

Answer 8

When reactant impurities bind to the active sites on catalyst, blocking the reactants

Question 9

Examples of a Heterogeneous Catalyst?

Answer 9

The contact process - V₂O₅(s)

Haber Process - Fe(s)

Question 10

Catalyst for Haber Process?

Answer 10

Fe(s)

Question 11

Equation for reaction between MnO₄⁻ & C₂O₄²⁻?

Answer 11

2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ |> 2Mn²⁺ + 8H₂O + 10CO₂