91Ó°ÊÓ

Predict the molecular geometry of the following: a. HOF b. \(\mathrm{NH}_{4}^{+}\) c. \(\mathrm{PF}_{5}\) d. \(\mathrm{ClF}_{4}^{+}\)

Which of the following molecules or ions are linear? a. \(\mathrm{SeF}_{2}\) b. \(\mathrm{CHCl}_{3}\) c. \(\mathrm{SeF}_{4}\) d. \(\mathrm{SnF}_{6}^{2-}\)

Which of the following molecules or ions are trigonal planar? a. \(\mathrm{BBr}_{3}\) b. \(\mathrm{AsH}_{3}\) c. \(\mathrm{ClF}_{4}^{-}\) d. \(\mathrm{TeF}_{5}^{-}\)

Explain how the dipole moment could be used to distinguish between the cis and trans isomers of 1,2 -dibromoethene:

Explain in terms of bonding theory why all four hydrogen atoms of allene, \(\mathrm{H}_{2} \mathrm{C}=\mathrm{C}=\mathrm{CH}_{2}\), cannot lie in the same plane.

Explain in terms of bonding theory why all atoms of \(\mathrm{H}_{2} \mathrm{C}=\mathrm{C}=\mathrm{C}=\mathrm{CH}_{2}\) must lie in the same plane.

What is the molecular orbital configuration of \(\mathrm{HeH}^{+} ?\) Do you expect the ion to be stable?

What is the molecular orbital configuration of \(\mathrm{He}_{2}^{+} ?\) Do you expect the ion to be stable?

Calcium carbide, \(\mathrm{CaC}_{2}\), consists of \(\mathrm{Ca}^{2+}\) and \(\mathrm{C}_{2}^{2-}\) (acetylide) ions. Write the molecular orbital configuration and bond order of the acetylide ion, \(\mathrm{C}_{2}{ }^{2-}\).

Sodium peroxide, \(\mathrm{Na}_{2} \mathrm{O}_{2}\), consists of \(\mathrm{Na}^{+}\) and \(\mathrm{O}_{2}^{2-}\) (peroxide) ions. Write the molecular orbital configuration and bond order of the peroxide ion, \(\mathrm{O}_{2}{ }^{2-}\).