ning OWLv2 | Online teaching and learning resource from Cengage Learning ChatOPT [Rovluw Toplen] [Refterenean] Use the References to access important values if needed for this question. The vapor pressure of chloroform is
at
. From the plot of vapor pressures vs temperature above, estimate the temperature at which the vapor pressure of heptane is
.
1 pt 1 req
The intermolecular forces in chloroform are
? than the intermolecular forces in heptane. tots.. 1 Bt Ireq
Trea Submit Answer. Retry Entire Group 2 more group attempts remaining (Previous Next) Sove and Exit Cengage Learning I Cengage Technical Support
prod04-cnow-owi.cengagenow.com earning OWLv2 | Online teaching and learning resource from Cengage Learning ChatOPT [Rovluw Toplen] [Refterenean] Use the References to access important values if needed for this question. The vapor pressure of chloroform is
at
. From the plot of vapor pressures vs temperature above, estimate the temperature at which the vapor pressure of heptane is
.
1 pt 1 req
The intermolecular forces in chloroform are
? than the intermolecular forces in heptane. tots.. 1 Bt Ireq
Trea Submit Answer. Retry Entire Group 2 more group attempts remaining (Previous Next) Sove and Exit Cengage Learning I Cengage Technical Support
Correct Answer:
The intermolecular forces in chloroform are stronger than the intermolecular forces in heptane.
Explanation
Chloroform and heptane differ in the types and strengths of their intermolecular forces, which directly affect their vapor pressures and boiling points.
Chloroform (CHCl₃) is a polar molecule due to the difference in electronegativity between carbon, hydrogen, and chlorine atoms. Its molecular geometry creates a net dipole moment. This polarity allows chloroform molecules to experience dipole-dipole interactions, which are significantly stronger than the London dispersion forces found in nonpolar molecules like heptane.
Heptane (C₇H₁₆), on the other hand, is a straight-chain hydrocarbon and is nonpolar. The only intermolecular force acting between heptane molecules is the London dispersion force, which arises due to temporary fluctuations in electron density. While these forces can become stronger with increasing molecular size and surface area, they are generally weaker than dipole-dipole interactions.
The strength of these forces influences vapor pressure. Substances with weaker intermolecular forces have higher vapor pressures at a given temperature because it is easier for their molecules to escape into the vapor phase. Substances with stronger intermolecular forces have lower vapor pressures because more energy is required to overcome these forces.
Therefore, at the same temperature, chloroform would have a lower vapor pressure than heptane due to its stronger intermolecular forces. This is also why chloroform usually has a higher boiling point compared to heptane. Boiling occurs when a liquid’s vapor pressure equals atmospheric pressure, so a substance with a lower vapor pressure at a given temperature must be heated more to boil.
In conclusion, the intermolecular forces in chloroform are stronger than those in heptane. This is evident from their respective vapor pressures, boiling points, and molecular structures.
