Exam 12: Intermolecular Forces: Liquids,solids,and Phase Changes

The density of solid sodium chloride,NaCl,is 2.17 g/cm³.Use your knowledge of the sodium chloride lattice to calculate the spacing between Na⁺ and Cl^- nearest neighbors,in cm.(Atomic masses (amu)are: Na,22.99;Cl,35.45.Also,1 amu = 1.661 $\times$ 10^-24 g)

Which of the following statements concerning a face-centered cubic unit cell and the corresponding lattice,made up of identical atoms,is incorrect?

Which of the following statements about the packing of monatomic solids with different unit cells is incorrect?

A metal such as chromium in the body-centered cubic lattice will have _______________ atom(s)per unit cell.

A temperature increase causes __________________ in the conductivity of a semiconductor.

The energy of a hydrogen bond is greater than that of a typical covalent bond.

Select the pair of substances in which the one with the higher vapor pressure at a given temperature is listed first.

Comparing the energies of the following intermolecular forces on a kJ/mol basis,which would normally have the highest energy (i.e. ,be the strongest force)?

Which of the following liquids is likely to have the highest surface tension?

Consider the following phase diagram and identify the process occurring as one goes from point C to point D.

For the solid forms of the following elements,which one is most likely to be of the molecular type?

Lead crystallizes in the face-centered cubic lattice.What is the coordination number for Pb?

Which of the following should have the highest boiling point?

Hexagonal close packing of identical atoms occurs when close-packed layers are stacked in an abcabc....arrangement.

Neon condenses due to

Which of the following atoms should have the greatest polarizability?

The phase diagram for xenon has a solid-liquid curve with a positive slope.Which of the following is true?

A cubic unit cell has an edge length of 400.pm.The length of its body diagonal (internal diagonal)in pm is therefore

Assuming that atoms are spherical,calculate the fraction of space which is occupied by atoms (i.e. ,the packing efficiency)in a metal with a simple cubic unit cell.

In metals,the conduction bands and valence bands of the molecular orbitals are separated by a large energy gap.