Answer:
The vapor pressure of acetic acid at 40 °C is 4569.4 mmHg.
Explanation:
- To solve this problem, we use Clausius Clapeyron equation: ln(P₁/P₂) = (ΔHvap / R) (1/T₁ - 1/T₂).
- The first case: P₁ = 1 atm = 760 mmHg and T₁ = 118 °C = 391 K.
- The second case: P₂ = ??? needed to be calculated and T₂ = 40 °C = 313 K.
- ΔHvap = 23.4 KJ/mole = 32.4 x 10³ J/mole and R = 8.314 J/mole.K.
- Now, ln(P₁/P₂) = (ΔHvap / R) (1/T₁ - 1/T₂)
- ln(760 mmHg /P₂) = (23.4 x 10³ J/mole / 8.314 J/mole.K) (1/391 K - 1/313 K)
- ln(760 mmHg /P₂) = (2814.53) (-6.373 x 10⁻⁴) = - 1.8
- Then, P₂ = (760 mmHg) / (0.1663) = 4569.4 mmHg.
So, The vapor pressure of acetic acid at 40 °C is 4569.4 mmHg.