91Ó°ÊÓ

Draw Lewis structures for \(\mathrm{CS}_{2}, \mathrm{PF}_{3}, \mathrm{SnH}_{4}, \mathrm{HONH}_{2}\)

Draw Lewis structures for \(\mathrm{H}_{2} \mathrm{CO}_{3}, \mathrm{HNO}_{3}, \mathrm{NO}, \mathrm{Be}\left(\mathrm{CH}_{3}\right)\)

Draw Lewis structures for \(\mathrm{BF}_{3}, \mathrm{SF}_{6}, \mathrm{XeF}_{2}, \mathrm{PF}_{3},\) IF

Write the MO eleciron configuration for the NO" ion. a. What is the bond order? b. Will the bond length be shorter or longer than in \(\mathrm{NO}\) ? c. How many unpaired electrons will be present? d. Will the unpaired electrons be concentrated more on the N or the O? Explain.

The resonance of \(\mathrm{BF}\), (page 145 ) is still a mather of some dispute becatise one chemist will point to the double bond in structure II (favorably); another will point to \(F^{+}\) (unfavorably). Surgest a molecule for which charges completely rule out resonance.

Write resonance sirvciures, including formal charges, for \(\mathbf{O}_{3}, \mathrm{SO}_{3}, \mathrm{NO}_{2}\)

The assumption was made ihat the carbon-carbon \(\sigma\) bond in \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\) is the same as that in \(\mathrm{CH}_{3} \mathrm{CH}_{3}\). In reality, is is probably somewhat stronger, biscuss.

The methyl sroup is usually considered to be electron-donating with regard to hydrogen, yet is electronegativity is not lower than hydrogen but slightly higher. Explain. (Hint: Think specifically about situations in which the methyl eroup is a good donor.