GATE 2024 CY – Question 59

Inorganic Chemistry · Organometallics: 18-Electron rule; metal-alkyl, metal-carbonyl, metal-olefin and metal-carbene complexes and metallocenes. Fluxionality in organometallic complexes. Types of organometallic reactions. Homogeneous catalysis – Hydrogenation, hydroformylation, methanol to acetic acid process, olefin metathesis and Wacker oxidation. Heterogeneous catalysis – Fischer-Tropsch reaction, Ziegler-Natta polymerization. · 2 marks · Numerical answer

The turnover frequency (in h−1) of a reaction where 5 mol% of a catalyst is required for 90% conversion in 3 h is ____. (rounded off to the nearest integer)

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Correct answer: 6

Explanation

The **turnover frequency (TOF)** is the number of moles of product formed per mole of catalyst per unit time:
$$\text{TOF}=\frac{\text{mol product}}{\text{mol catalyst}\times\text{time}} .$$

Take 1 mol of starting material.
- 90% conversion gives 0.90 mol of product.
- 5 mol% catalyst means 0.05 mol of catalyst.
- Time: 3 h.

$$\text{TOF}=\frac{0.90}{0.05\times3}=\frac{0.90}{0.15}=\mathbf{6\ h^{-1}}.$$