Sodium carbonate can be made by heating sodium bicarbonate: 2NaHCO₃(s) $\rarr$ Na₂CO₃(s) + CO₂(g) + H₂O(g)
Given that $\Delta$ H° = 128.9 kJ/mol and $\Delta$ G° = 33.1 kJ/mol at 25°C, above what minimum temperature will the reaction become spontaneous under standard state conditions?

Question

Sodium carbonate can be made by heating sodium bicarbonate: 2NaHCO₃(s)

\rarr

Na₂CO₃(s) + CO₂(g) + H₂O(g)
Given that

\Delta

H° = 128.9 kJ/mol and

\Delta

G° = 33.1 kJ/mol at 25°C, above what minimum temperature will the reaction become spontaneous under standard state conditions?

Quizplus · Accepted Answer

The reaction becomes spontaneous when $\Delta$G° = 0. Using the equation $\Delta$G° = $\Delta$H° - T$\Delta$S°, solve for T: T = $\Delta$H°/$\Delta$S°. Given $\Delta$H° = 128.9 kJ/mol and $\Delta$G° = 33.1 kJ/mol, $\Delta$S° = ($\Delta$H° - $\Delta$G°)/T = 95.8 J/mol·K. Solving for T gives T = 128900 J/mol / 95.8 J/mol·K = 1345 K. However, this calculation seems incorrect; the correct temperature should be 401 K, indicating a mistake in the initial calculation or assumptions.

Sodium Carbonate Can Be Made by Heating Sodium Bicarbonate: 2NaHCO3(s) →\rarr→

Sodium Carbonate Can Be Made by Heating Sodium Bicarbonate: 2NaHCO₃(s) $\rarr$