Structure 2.2—The covalent model：練習問題

Which of the following compounds contains a dative (coordinate) covalent bond?

How many sigma (\(\sigma\)) and pi (\(\pi\)) bonds are present in a molecule of ethyne, \(C_2H_2\)?

Which molecule is polar but contains non-polar bonds?

Which of the following best describes the fundamental nature of a covalent bond?

Which set of molecules is arranged in order of decreasing bond angle?

Describe how a dative (coordinate) covalent bond differs from a normal covalent bond.

Explain how the concept of delocalized pi electrons in the nitrate ion ($$NO_3^-$$) accounts for its observed bond lengths and overall stability, despite its individual resonance structures suggesting alternating single and double bonds.

Consider the sulfite ion, $$SO_3^{2-}$$.

a) Draw all plausible Lewis structures for the sulfite ion, showing all valence electrons and formal charges where applicable. Identify the most stable resonance structure(s) based on formal charges.

b) Determine the electron domain geometry and molecular geometry around the central sulfur atom using VSEPR theory. State the approximate bond angle(s).

c) Discuss the hybridization of the central sulfur atom in the sulfite ion.