Exam 4 Study Guide
Exam 4 Study Guide CHMY 141N - 00
Popular in College Chemistry I
Popular in Chemistry
This 4 page Study Guide was uploaded by Isabella Sturgeon on Monday November 30, 2015. The Study Guide belongs to CHMY 141N - 00 at University of Montana taught by Mark Cracolice (P) in Fall 2015. Since its upload, it has received 18 views. For similar materials see College Chemistry I in Chemistry at University of Montana.
Reviews for Exam 4 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 11/30/15
Chemistry 141 Study Guide Exam 4 Lesson 27 How do Atoms Combine to Form Ionic Compounds and Molecules This lesson is about ionic compounds forming This happens when atoms lose an electron to another atom So one atom gains an electron while one loses one These generally occur between a metal and nonmetal element Metals have a tendency to lose electrons while nonmetals tend to gain electrons This also discusses the bonds created between to nonmetals when they share their electrons instead of steal metal s electrons These bonds are called covalent bonds There can be more than one of these bonds also if the nonmetals share more than one set of electrons Covalent bonds can be polar or nonpolar When there is a large difference in electronegativity the bond becomes more polar The period trend of electronegativity is that it increases towards the right and top Key terms Anion An ion that has a negative charge and gains electrons Cation An ion that has a positive charge and loses electrons Crystal a metal and nonmetal that have ionic bonded Covalent bond the bond between two nonmetal atoms where they share electrons onic bond the bond between a metal and nonmetal that steal or give up electrons Electron cloud charge density the area where the two electrons formed between the two nuclei of bonded atoms Electronegativity the ability for an atom to attract electron pairs to itself Lewis structure the drawn out structure depicting all bonds and unshared electron pairs of a covalent bonded molecule Lone pair a pair of electrons that are not bonded Nonpolar bond a covalent bond where the two atoms have a small difference in electronegativity Polar bond a covalent bond where the two atoms have a large difference in electronegativity Lesson 28 How can the TwoDimensional Arrangement of Atoms in Molecules be Predicted This lesson is about determining the likely two dimensional shape of the molecule based on the number of valance electrons This requires mastering the Lewis structure Determine valance electrons and the central atom to complete a first draft Make sure to analyze the formal charge of the Lewis structure For the Lewis structures you need to count all the valance electrons to see if they match with the drawn number of electrons in the first Lewis structure draft If not add or delete some electron pairs and create double or triple bonds or lone pairs Key terms somer a Lewis structure that can be drawn in another way Formal charge the charge based on the wanted electrons for each atom and the number they actual get in the Lewis structure this number should match the overall charge of the molecule Lesson 29 How are Covalent Bonds in Molecules Optimally Arranged and What are Their Lengths and Strengths This lesson is all about multiple bonds in molecules How do we decide where the double bond should go Sometimes it is obvious where the double bonds goes but other times it could go in multiple places This lessons shows how to indicate that a double bond can go in multiple places This double bonds that ca go multiple places are drawn as multiple Lewis structures called resonance structures Remember that central atoms that only go to the p block can only have an octet yet central atoms that are in the d or f block can break the octet rule The number of the bond is the bond order So a single bond has a bond order of 1 a double bond has the bond order of 2 ect Multiple bonds are stronger than single bonds and allow for less rotation To figure out bond order in a molecule with resonance you take the number of shared electron pairs between the central atom and divide that by the number of links We can also determine the change in enthalpy from bonds It is equal to the sum of the bonds broken plus the sum of the bonds formed Make sure to draw the Lewis structure to include all of the bonds formed and broken Key terms Resonance structures the alternative Lewis structures that are possible for a molecule based on bonds Electrostatic potential map shows the results of calculations of charge distribution in polyatomic ions Resonance hybrid the combination of all resonance structures usually has the bond distributed amongst all other bonds Free radical a single electron it is believed that the interaction between free radicals and DNA can lead to some types of cancer Lesson 30 How can the ThreeDimensional Arrangement of Atoms in Molecules be Predicted This lesson is all about determining the probable 3D shape of a molecule based on its bonding and Lewis structure VSPER is a theory that basically states that electrons repel each other The electron pair geometry is just based off of the number of pairs of electrons around the central atom Molecular geometry is based on the unshared pared and bonding electron pairs This lesson also shows a new way to draw molecules the wedgeanddash diagram These show the 3D characteristics of the molecule A wedge shows the atom coming forward while the dash shows an atom going towards the back These do not include lone pairs of electron of bonded Electron pair Molecular geometry pairs around electron pairs geometry central atom to central atom 2 2 Linear Linear 3 3 Trigonal Planar Trigonal Planar 3 2 Trigonal Planar Angular 4 4 Tetrahedral Tetrahedral 4 3 Tetrahedral Trigonal Pyramidal 4 2 Tetrahedral Bent 5 5 Trigonal Bipyramidal Trigonal Bipyramidal 5 4 Trigonal Bipyramidal See saw 5 3 Trigonal Bipyramidal T shaped 5 2 Trigonal Bipyramidal Linear 6 6 Octahedral Octahedral 6 5 Octahedral Square pyramidal 6 4 Octahedral Square planar Lesson 31 How is Bonding Explained When the Atomic Orbital Overlap Model Fails This lesson introduces the problems in bonding model overlap Instead of simply overlapping the central atom will develop a hybridized orbital based on how many bonds it forms They are labeled based on there energy sub levels S P D This also introduces the two types of bonds sigma and pi Sigma bonds overlap end to end and are shown as single bonds Pi bonds are side to side bonding ridization Number of sin le bonds and electron irs H 2 Remember Lesson 32 was skipped this semester Lesson 33 What Particulate Level Interactions Govern the Liquid State This lesson is about the properties of liquid and how those relate to the forces that hold liquid molecules together These force are called nter Molecular Forces There are three mains types listed from weakest to strongest if everything is equal induced dipole forces dipole forces and hydrogen bonding Two things to remember 1 If a molecule is large its induced dipole force become stronger than any other inter molecule force and 2 Hydrogen bonding is not really a bond its just a strong attraction There are five properties of liquids discussed vapor pressure partial pressure of the gaseous particles heat of vaporization the energy required to to change one mole of liquid to one mole of gas at constant temperature and pressure boiling point the average kinetic energy that can overcome the forces of attraction to hold particles in their liquid state viscosity the resistance to flow and surface tension the tendency to to minimize surface by attracting inwards All properties other than vapor pressure increase as the force strength increases The force can be determined by first drawing the Lewis structure From there if there are no bonds between H and F N or 0 there cannot be hydrogen bonding if the molecule is symmetrical there is no dipole force if not symmetric and if the molecule is polar there is a dipole All molecules have induced dipole forces Key terms All were defined in paragraph above Lesson 34 What are the Characters of Equilibrium This lesson discusses the relationship between a liquid and its vapor Boiling point is defined in a little bit of a different way Phase diagrams are also introduced in this lesson The triple point is the temperature and pressure at which all three phases can exist Key terms Boiling point when the liquid vapor pressure and pressure above the liquid are in equilibrium Condensation rate the rate at which condensation occurs Critical point temperature and pressure where liquid vapor pressure does not exist Sublimation solid to gas phase change Phase diagram shows the three phase and which temperature and pressure they change at
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'