Methanol, CH3OH\text{CH}_3\text{OH}CH3OH, is manufactured on an industrial scale from a mixture of carbon monoxide and hydrogen, as shown in equilibrium 1.
CO(g)+2H2(g)⇌CH3OH(g)ΔH=−91 kJ mol−1Equilibrium 1 \text{CO(g)} + 2\text{H}_2\text{(g)} \rightleftharpoons \text{CH}_3\text{OH(g)} \quad \Delta H = -91 \text{ kJ mol}^{-1} \quad \text{\textbf{Equilibrium 1}} CO(g)+2H2(g)⇌CH3OH(g)ΔH=−91 kJ mol−1Equilibrium 1Predict the conditions of pressure and temperature that would yield the maximum equilibrium amount of CH3OH\text{CH}_3\text{OH}CH3OH in equilibrium 1. Explain your reasoning.
A catalyst is employed in the industrial synthesis of methanol in equilibrium 1. State two ways in which the use of catalysts contributes to making chemical manufacturing processes more sustainable and environmentally friendly.
Standard entropy values for the substances involved are listed in the table below.
| Substance | CO(g)\text{CO(g)}CO(g) | H2(g)\text{H}_2\text{(g)}H2(g) | CH3OH(g)\text{CH}_3\text{OH(g)}CH3OH(g) |
|---|---|---|---|
| Sθ / J K−1mol−1S^\theta \text{ / J K}^{-1}\text{mol}^{-1}Sθ / J K−1mol−1 | 198 | 131 | 240 |
An industrial chemist evaluates a proposal to operate the reactor at 380 K380 \text{ K}380 K using equilibrium 1. Determine, by means of a calculation, whether the production of methanol is thermodynamically feasible at 380 K380 \text{ K}380 K.
At 298 K298 \text{ K}298 K, the standard Gibbs free energy change, ΔG\Delta GΔG, for the reaction in equilibrium 1 is −2.54×104 J mol−1-2.54 \times 10^4 \text{ J mol}^{-1}−2.54×104 J mol−1.
ΔG\Delta GΔG is related to the equilibrium constant KpK_pKp by the expression:
ΔG=−RTlnKp \Delta G = -RT \ln K_p ΔG=−RTlnKpWhere:
Calculate the value of KpK_pKp for equilibrium 1 at 298 K298 \text{ K}298 K. Give your answer to 3 significant figures and state its units, assuming partial pressures are measured in atm\text{atm}atm.
