Answer: 73 °C.
Explanation:
See figure attached.
1) You need to use a vapor pressure table or graph.
2) Find attached the graph that accompanies this question.
3) To find the temperature at which the vapor pressure of ethanol equals 80 kPa, identify such pressure in the vertical axis, then move parallel to the horizontal axis until you reach the curve of ethanol, then move vertically downward until the horizontal axis, where you read the temperature. There you can see that it is between the marks for 70 and 75°C, which means that it is about 72.5°C.
