1.3 Covalent Bonds Structural formulas of this type in which electrons are represented as dots are called Lewis structures The amount of energy required to dissociate a hydrogen molecule H2 to two sep arate hydrogen atoms is called its bond dissociation energy (or bond energy). For H it is quite large, being equal to 435 k/mol(104 kcal/mol). The main contributor to the strength of the covalent bond in H, is the increased binding force exerted on its two electrons. Each electron in H,"feels"the attractive force of two nuclei, rather than one as it would in an isolated hydrogen atom Covalent bonding in F2 gives each fluorine 8 electrons in its valence shell and a stable electron configuration equivalent to that of the noble gas neon: Two fluorine atoms. each with seven electrons in nding by way of ts valence shell electron pai PROBLEM 1.5 Hydrogen is bonded to fluorine in hydrogen fluoride by a cova- lent bond. Write a Lewis formula for hydrogen fluoride The Lewis model limits second-row elements(Li, Be, B, C, N, O, F, Ne) to a total of 8 electrons(shared plus unshared) in their valence shells. Hydrogen is limited to 2. Most of the elements that we'll encounter in this text obey the octet rule: in forming compounds they gain, lose, or share electrons to give a stable electron configuration characterized by eight valence electrons. When the octet rule is satisfied for carbon nitrogen, oxygen, and fluorine, they have an electron configuration analogous to the noble gas neon Now lets apply the Lewis model to the organic compounds methane and carbon tetrafluoride to write a Combine. C. and four h Lewis structure H: C: H for methane H Combine·C· and four Lewis structure F: C: F for carbon tetrafluoride Carbon has electrons in its valence shell in both methane and carbon tetrafluoride. By forming covalent bonds to four other atoms, carbon achieves a stable electron configu ration analogous to neon. Each covalent bond in methane and carbon tetrafluoride is quite strong--comparable to the bond between hydrogens in H2 in bond dissociation energy PROBLEM 1.6 Given the information that it has a carbon -carbon bond write a satisfactory Lewis structure for C2H(ethane) Representing a 2-electron covalent bond by a dash () the Lewis structures for hydrogen fluoride, fluorine, methane, and carbon tetrafluoride become Back Forward Main MenuToc Study Guide ToC Student o MHHE WebsiteStructural formulas of this type in which electrons are represented as dots are called Lewis structures. The amount of energy required to dissociate a hydrogen molecule H2 to two sep￾arate hydrogen atoms is called its bond dissociation energy (or bond energy). For H2 it is quite large, being equal to 435 kJ/mol (104 kcal/mol). The main contributor to the strength of the covalent bond in H2 is the increased binding force exerted on its two electrons. Each electron in H2 “feels” the attractive force of two nuclei, rather than one as it would in an isolated hydrogen atom. Covalent bonding in F2 gives each fluorine 8 electrons in its valence shell and a stable electron configuration equivalent to that of the noble gas neon: PROBLEM 1.5 Hydrogen is bonded to fluorine in hydrogen fluoride by a cova￾lent bond. Write a Lewis formula for hydrogen fluoride. The Lewis model limits second-row elements (Li, Be, B, C, N, O, F, Ne) to a total of 8 electrons (shared plus unshared) in their valence shells. Hydrogen is limited to 2. Most of the elements that we’ll encounter in this text obey the octet rule: in forming compounds they gain, lose, or share electrons to give a stable electron configuration characterized by eight valence electrons. When the octet rule is satisfied for carbon, nitrogen, oxygen, and fluorine, they have an electron configuration analogous to the noble gas neon. Now let’s apply the Lewis model to the organic compounds methane and carbon tetrafluoride. Carbon has 8 electrons in its valence shell in both methane and carbon tetrafluoride. By forming covalent bonds to four other atoms, carbon achieves a stable electron configu￾ration analogous to neon. Each covalent bond in methane and carbon tetrafluoride is quite strong—comparable to the bond between hydrogens in H2 in bond dissociation energy. PROBLEM 1.6 Given the information that it has a carbon–carbon bond, write a satisfactory Lewis structure for C2H6 (ethane). Representing a 2-electron covalent bond by a dash (—), the Lewis structures for hydrogen fluoride, fluorine, methane, and carbon tetrafluoride become: Combine to write a Lewis structure for methane and fourC H CH H H H Combine to write a Lewis structure for carbon tetrafluoride and fourC F F F F F C Fluorine molecule: covalent bonding by way of a shared electron pair F F Two fluorine atoms, each with seven electrons in its valence shell F F 1.3 Covalent Bonds 13 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website