CHEM 104 Study Guide - Winter 2018, Comprehensive Midterm Notes - Ion, Acid, Ph
CHEM 104
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Lecture 1-Chen 104, - VSEPR, VBT, and Polarity
Pre-class 01/24/17
Chem 103 review
e- = electrons
1. Lewis Structures
• single covalent bond: formed when two atoms share one pair of electrons.
ex.: diatomic molecules ( )
• Lewis structure: shows all valence e- as dots and others as lines that represent covalent
bond
Octet Rule:
• Atoms with more than two valence e- achieve a noble-gas structure by sharing enough
e- to aHain an octet of valence e- ( configuration)
• to form bonds, main-group elements gain, lose, or share electrons to achieve a stable
configuration characterized by 8 valence r-
bonding e-: shared electron pairs
lone pair e-: unshared pairs
* the number of e- that an atom of a main-group element must share to achieve an octet
euals eight ius it’s a-group number *
double-bond: two shared pairs of electrons
triple-bond: two shared e- pairs
ex.: (of multiple bonds)
double bond triple bond
find more resources at oneclass.com
find more resources at oneclass.com
carbonyl group: one of several functional groups that are very important in organic and
biochemical molecules
2. Polarity
nonpolar covalent bond: equal sharing of the bonding election pair
polar covalent bond: bonding e- are shared unequally
3. Electronegativity
electronegativity: ability of an atom in a covalent bond to attract shared e- to itself
F = most electronegative
• metals (least electronegative) lose e- when they form ionic compounds
nonmetals (most electronegative) usually gain
= less electronegative atom
= more electronegative atom
nonpolar
covalent
bond
polar
covalent
bond
ionic
bond
used to
predict polanty
decreases down a group
increases across
overall trend
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 1-chen 104, - vsepr, vbt, and polarity. Chem 103 review e- = electrons: lewis structure: shows all valence e- as dots and others as lines that represent covalent, lewis structures, single covalent bond: formed when two atoms share one pair of electrons. (cid:1832) (cid:1832) ex. : diatomic molecules ((cid:2870),(cid:1832)(cid:2870),(cid:1829)(cid:2870)) (cid:1829) (cid:1829) e- to ahain an octet of valence e- ((cid:2870)(cid:2872) configuration) bond. * the number of e- that an atom of a main-group element must share to achieve an octet e(cid:395)uals eight (cid:373)i(cid:374)us it"s a-group number * double-bond: two shared pairs of electrons (cid:1829)=(cid:1829) (cid:1829) (cid:1829) triple-bond: two shared e- pairs ex. C || / \ h h double bond (cid:1840)(cid:2870) (cid:1840) (cid:1840): triple bond carbonyl group: one of several functional groups that are very important in organic and biochemical molecules. C=o: polarity nonpolar covalent bond: equal sharing of the bonding election pair polar covalent bond: bonding e- are shared unequally.
