Chemistry 111 - Final Exam Review

Chemistry 111 - Final Exam Review - CHEM 111 From Chapter 9...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEM 111 Exam 4 Review Sheet From Chapter 9 you should: - Draw Lewis Structures (molecules, polyatomic ions, exceptions to octet rule, and those with more than one central atom). Ex. Ethane. - Formal Charge: Hypothetical charge you obtain by assuming that bonding electrons are equally shared between bonded atoms and that electrons of each lone pair belong completely to one atom. o Equation: (Periodic electrons) – (number of bonds) – (number of non-bonded) = FORMAL CHARGE o RULE A Write the Lewis Dot formula that has the lowest magnitudes of formal charges. o RULE B When two Lewis formulas for a molecule have the same magnitude choose the negative formal charge or more electronegative atom. - Delocalized Electrons: An electron that is shared over the entire region of the molecule; seen most often in resonance. - Bond Energies—Generally, the enthalpy of reaction is approx. equal to the sum of the bond energies; if you subtract the sum of the bond energies from the bonds broken. o Example: H H H H C = C + (H-Br) H – C – C – Br H H H H Bonds Broken -> (C=C), 4(C-H), (H-Br) Bonds Formed -> 5(C-H), (C-Br), (C-C) (Cancel out the 4(C-H) = left with 1(C-H) in “formed” (Add bonding energies found in table 9.5 [given] ) Subtract: (Bonds broken) – (Bonds formed) = Change in Energies From Chapter 10 you should: - VSEPR Theory: 1) Write the electron dot structure. 2) Determine the number of electron pairs.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

Chemistry 111 - Final Exam Review - CHEM 111 From Chapter 9...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online