Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

11.25. Intermolecular Forces The following picture represents atoms of hypotheti

ID: 928354 • Letter: 1

Question

11.25. Intermolecular Forces

The following picture represents atoms of hypothetical, nonmetallic, monatomic elements A, B, and C in a container at a temperature of 4 K (the piston maintains the pressure at 1 atm). None of these elements reacts with the others.

a. What is the state (solid, liquid, or gas) of each of the elements represented in the container?

b. Rank the elements in the container from greatest to least, in terms of intermolecular interactions. Explain your answer.

c. What type(s) of intermolecular attractions are present in each of these elements?

d. Explain which element has the greatest atomic mass.

e. One of the elements in the container has a normal boiling point of 2 K. Which element would that be (A, B, or C)? How do you know?

f. One of the elements has a melting point of 50 K. Which element would that be (A, B, or C)? Why?

Explanation / Answer

A is solid, as atoms are very closely packed. B is liquid, as atoms are somewhat free to move. C is gas, as atoms are far to each other.

Intermolecular forces decrease from solid to liquid to gas. So, order of intermolecular forces:

A > B > C

A (solid) can have metallic, molecular, ionic or covalent network. B (liquid) can have dispersion forces or dipole-dipole etc. C (gas) has weak intermolecular forces.

Element A has the greatest atomic mass, as it is solid.

Container temeprature is 4 K, and boiling point of element is 2 K. Element exists as vapor at 4 K, and thus C.

Container temeprature is 4 K, and melting point of element is 50 K. Element exists as solid at 4 K, and thus A.