Question

sep interpret data the table compares vapor pressure values for water, ethanol, and diethyl ether at six temperatures. determine the approximate normal boiling point for each substance. what do the data suggest about the relative strength of attraction between particles in each substance? vapor pressure (in kpa) of three substances at different temperatures substances 0°c 20°c 40°c 60°c 80°c 100°c water 0.61 2.33 7.37 19.92 47.34 101.33 ethanol 1.63 5.85 18.04 47.02 108.34 225.75 diethyl ether 24.70 58.96 122.80 230.65 399.11 647.87

Explanation:

Step1: Recall boiling - point definition

The normal boiling point is the temperature at which the vapor pressure of a liquid equals the standard - atmospheric pressure (101.33 kPa).

Step2: Determine boiling points from the table

For water, when the vapor pressure is 101.33 kPa, the temperature is 100°C. So the normal boiling point of water is 100°C.
For ethanol, we look for the vapor - pressure value closest to 101.33 kPa. When the vapor pressure is 108.34 kPa at 80°C and 47.02 kPa at 60°C, by interpolation or just observing the trend, the normal boiling point of ethanol is around 78°C.
For diethyl ether, since its vapor pressure exceeds 101.33 kPa even at 20°C (58.96 kPa) and 40°C (122.80 kPa), its normal boiling point is around 35°C.

Step3: Analyze particle - attraction strength

The lower the normal boiling point of a substance, the weaker the intermolecular forces (attraction between particles). Diethyl ether has the lowest boiling point, so the attraction between its particles is the weakest. Water has the highest boiling point among the three, so the attraction between water particles is the strongest. Ethanol has an intermediate boiling point, so the attraction between its particles is intermediate.

Answer:

The normal boiling point of water is 100°C, of ethanol is around 78°C, and of diethyl ether is around 35°C. The strength of attraction between particles is strongest in water, intermediate in ethanol, and weakest in diethyl ether.