Exam 11: Intermolecular Forces and the Physical Properties of Liquids and Solids

Octane,C₈H₁₈,boils at 125°C,whereas water boils at 100°C.This information suggests that the dispersion forces in nonpolar octane molecules are stronger than the dispersion forces and hydrogen bonding in water.

Based on the phase diagram of a pure substance given below,what change of state occurs as the substance changes from point C to point D?

Which one of the following pure substance has both dispersion forces and dipole-dipole forces?

What is another name given to dispersion forces?

What is defined as the number of atoms surrounding an atom in a crystal lattice and indicates how tightly the atoms are packed together?

Which one of the following involves ion-dipole interactions?

Which one of the following crystallizes in a metallic lattice?

Which substance has the highest vapor pressure at room temperature?

Consider the phase diagram shown below. a.What phase(s)is/are present at point A? b.What phase(s)is/are present at point B? c.Name point C and explain its significance. d.Starting at D,if the pressure is lowered while the temperature remains constant,describe what will happen.

The vapor pressure of ethanol is 400.mmHg at 63.5°C.Its molar heat of vaporization is 39.3kJ/mol.What is the vapor pressure of ethanol,in mmHg,at 34.9°C? (R = 8.314 J/K • mol)

______________ is the name given to the phase change from a solid directly to a gas.

Vanadium crystallizes in a body-centered cubic lattice,and the length of the edge of a unit cell is 305 pm.What is the density of V?

The strongest intermolecular interactions between hydrogen fluoride (HF)molecules arise from

Which has the highest surface tension at a given temperature?

Use the graph of vapor pressure to determine the normal boiling point of O₂.