Question

Statement-1 : Transition metals are good catalysts.
Statement-2 : V₂O₅ or Pt is used in the preparation of H₂SO₄
by contact process.

Answer 1

Transition metals are good catalysts

Explanation:

Transitional metals are belongs to d-block of the periodic table  but all the transitional metals are not belong to the block but they must contain an incompletely filled d-orbit.

Transitional metals have valance electrons in two shells and they are called as good catalyst because they can easily eliminate or take electrons from the other molecules.Ex- Chromium,nickel,iron etc.

The catalyst metals increases the frequency of collisions between the reactant but don't change their physical or chemical property.

V₂O₅ or Pt is used in the preparation of H₂S0₄

Explanation:

To prepare sulfuric acid, Pt or V₂O₅ is used as a catalyst for the reaction.

The process contain 5 steps-

1. Sulfur and oxygen combines to form sulfur dioxide.
2. Purifying the sulfur dioxide
3. In presence of vanadium pentoxide, excess amount of  oxygen is added to sulfur dioxide.
4. formation of sulfur trioxide which is added to the sulfuric acid that form disulfuric acid (oleum)

    5.Then oleum is added to the water that reacts to form  sulfuric acid.

2SO₂+O₂⇄2SO₃

2SO₂+4V⁵⁺+20²⁻⇒2SO₃+4V⁴⁺(Oxidation of SO₂)

4V⁴⁺+O₂ = 4V⁵⁺+2O₂⁻               (Oxidation of V⁴⁺)

H₂SO₄+SO₃= H₂S₂O₇(oleum)

H₂S₂O₇+H₂0=H₂SO₄