Quiz 1 - Covalent Bonding and Compounds | Covalent Bonding and Molecular Structure

General Chemistry 1 - Quiz 1 - Covalent Bonding and Compounds


How many covalent bonds should form a neutral oxygen atom to follow the octet rule?

Electronic configuration of O (Z = 8): 1s2 2s2 2p4 ⇒ 6 valence electrons

A neutral oxygen atom needs 2 more electrons to follow the octet rule


What type of bond exists between the nitrogen atoms of N2H2?


Which of the following species has a triple covalent bond?


What is the formal charge of boron atom in the molecule BF4-?

nb of valence electrons in a free boron atom: 3

nb of valence electrons in the bound boron atom of BF4-: 4

Formal charge = 3 – 4 = -1



Which of the following atoms could have an expanded valence shell?

Valence shell of Li, O and Ne: n =2

Valence shell of S: n = 3

Expanded valence shell can happen only for atoms with a valence shell n  3


Which species has the longest carbon-oxygen bond?

In CO32- (carbonate ion), the resonance structures distribute the double-bond character among the three C-O bonds, making them longer than a typical C=O bond in CO2, COS, and HCO2-.


What is the formal charge on the chlorine atom in the oxyacid HOClO2 if it contains only single bonds?

Chlorine in HOClO2 with single bonds has a formal charge of +2, calculated by considering the valence electrons (7), non-bonding electrons (2), and bonding electrons (3).


Which resonance form makes the greatest contribution to the structure of N2O?

This form places negative charge on the more electronegative oxygen, making it more stable.


The concept of resonance is used to describe molecular structures which

Resonance forms are different Lewis structures that represent the same molecule, showing the delocalization of electrons.


What is the correct name for N2O4?

The correct naming convention for molecular compounds uses prefixes to denote the number of atoms. N2O4 is named dinitrogen tetraoxide. The final "a" or "o" of a prefix is often dropped if the element name begins with a vowel to make the name easier to pronounce.