Find the temperature at which ethanol boils on a day in the mountains when the barometric pressure is 547 mmHg. (Given: The heat of vaporization of ethanol is 39.3 kJ/mol; the normal boiling point of ethanol is 78.3^$\circ$C.) A) 10.0^$\circ$C B) 69.9^$\circ$C C) 74.6^$\circ$C D) 76.5^$\circ$C E) 77.9^$\circ$C

Question

Quizplus · Accepted Answer

The boiling point of a liquid decreases when the external pressure is reduced, such as at higher altitudes. Since the normal boiling point of ethanol is 78.3°C at 1 atm (760 mmHg), and the pressure in the question is lower (547 mmHg), the boiling point of ethanol would be lower than 78.3°C. Among the options, 69.9°C is the only temperature significantly lower than 78.3°C, making it the correct choice.

Find the Temperature at Which Ethanol Boils on a Day ∘\circ∘

Find the Temperature at Which Ethanol Boils on a Day $\circ$