Question

Use the observation in the first column

Answer 1

Answer:

A. Substance E

A. Substance C

A. Substance A  

Explanation:

Given that:

At 4 °C, Substance E has a vapor pressure of 86. torr and Substance F has a vapor pressure of 136. torr

Which has a higher boiling point?

A. Substance E

B. Substance F

C. Neither,EandF have the same boiling point

The vapor pressure varies inversely proportional to the boiling point.

$\mathbf{vapor \ pressure \ \ \alpha \ \ \dfrac{1}{boiling \ point}}$

Therefore, the lower the vapor pressure, the higher the boiling point.

At 4°C, Substance E with a lower vapor pressure of 86. torr will have a higher boiling point from the given information.

2.

Recall that :

$\mathbf{vapor \ pressure \ \ \alpha \ \ \dfrac{1}{enthalpy \ of \ vaporization}}$

therefore, the lower the enthalpy of vaporization, the higher the vapor pressure at any given temperature.

Given that:

Substance C has an enthalpy of vaporization smaller than that of substance D. Then, substance C has a higher vapor pressure.

3.

We've earlier said that:

The vapor pressure varies inversely proportional to the boiling point.

$\mathbf{vapor \ pressure \ \ \alpha \ \ \dfrac{1}{boiling \ point}}$

Therefore, the lower the vapor pressure, the higher the boiling point.

As such, Substance A will have a higher boiling point.