Sketch the probable geometric shape of a molecule of (a) \(\mathrm{N}_{2} \mathrm{O}_{4}\left(\mathrm{O}_{2} \mathrm{NNO}_{2}\right) ;\) (b) \(\mathrm{C}_{2} \mathrm{N}_{2}(\mathrm{NCCN}) ;\) (c) \(\mathrm{C}_{2} \mathrm{H}_{6}\) \(\left(\mathrm{H}_{3} \mathrm{CCH}_{3}\right) ;(\mathrm{d}) \mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}\left(\mathrm{H}_{3} \mathrm{COCH}_{3}\right)\).

(a) For \$\mathrm{N}_{2} \mathrm{O}_{4}\left(\mathrm{O}_{2} \mathrm{NNO}_{2}\right)\$, start by identifying the central atom (N) and arrange other atoms around it. Then fill in the valence electrons, making sure each atom besides hydrogen has an octet.(b) For \$\mathrm{C}_{2} \mathrm{N}_{2}(\mathrm{NCCN})\$, similarly identify the central atoms (C) and arrange N atoms around them. Then fill in the valence electrons.(c) For \$\mathrm{C}_{2} \mathrm{H}_{6}(\$\mathrm{H}_{3} \mathrm{CCH}_{3}\$)\$, identify the central atoms (C) and arrange H atoms around them. Then fill in the valence electrons.(d) For \$\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}(\mathrm{H}_{3} \mathrm{COCH}_{3})\$, identify the central atoms (C) and arrange H and O atoms around them. Then fill in the valence electrons.

(a) For \$\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{O}_{2} \mathrm{NNO}_{2})\$, the N atom is surrounded by one lone pair and three atoms. Therefore, its electron pair geometry is tetrahedral and its molecular shape is trigonal pyramidal.(b) For \$\mathrm{C}_{2} \mathrm{N}_{2}(\mathrm{NCCN})\$, the C atoms are surrounded by two atoms. Therefore, its electron pair geometry is linear and its molecular shape is linear.(c) For \$\mathrm{C}_{2} \mathrm{H}_{6}(\mathrm{H}_{3} \mathrm{CCH}_{3})\$, each C atom is surrounded by three atoms. Therefore, its electron pair geometry is tetrahedral and its molecular shape is tetrahedral.(d) For \$\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}(\mathrm{H}_{3} \mathrm{COCH}_{3})\$, the C atom attached to O is surrounded by three atoms and a lone pair. Therefore, its electron pair geometry is tetrahedral and its molecular shape is trigonal pyramidal.