Problem+Set+12

Problem Set 12

Above is the Lewis structure for sulfur hexaflouride. According to the octet rule, this configuration should not be possible because sulfur has 12 valence electrons. Expanded octets, however, allow this to be possible. An expanded octet refers to the ability for a given central atom to use its 'd' orbitals in order to obtain more valence electrons. Since sulfur is in the third energy level, it has the capability to use its 3d orbitals so that more electrons can bond with sulfur. In this configuration, two pairs of shared electrons are shared in sulfur's 3d orbitals, not the 3s or 3p orbitals. Expanded octets give atoms more orbitals available for bonding.
 * 7. Some compounds are stable with what is referred to as an //expanded octet//. Sulfur hexaflouride is one such compound. Draw a Lewis structure for this compound and explain how an expanded octet can be possible.**
 * -Alex Kaplan**

( While this picture is inaccurate for its depiction of electron configuration, it is good visual for the electron transfer and formation of NaCl) The compound hydrogen fluoride is one such polar covalent compound, where because of fluoride’s higher electronegativity; the electron spends more time around said ion than hydrogen; their difference is 1.9. Now, with sodium chloride, this compound is considered ionic. However, it is impossible for a compound to be a true ionic compound. Why? This is because of that one electron that is given off by sodium and given to chlorine. By quantum mechanics, we don’t know where that electron will be one hundred percent of the time; it might travel around, stay close to sodium, thus being shared between the two; sometimes. This is why it is hard to differentiate the difference between the two because there are no true bonds that are completely ionic. Sadly the picture of our whiteboard will not post. (Sam Crowe)
 * 8. Explain why it is often difficult to define the difference between an //ionic bond// and a //polar covalent bond//.**