Polarity – It exists in two forms Bond Polarity We looking at the difference in electronegativies between atoms to determine how they share their electrons.

Slides:



Advertisements
Similar presentations
Chapter 9 Notes – Part III Mr Nelson Polarity But just because a molecule possesses polar bonds does not mean the molecule as a whole will be polar.
Advertisements

Electronegativity and Bond Type
Polarizability More electrons are further from the nucleus Nucleus has less pull on far off electrons The more electrons the more “polarizability” More.
Polar Molecules H F electron rich region electron poor region d+ d-
Problem Set: Polar, Nonpolar, and Ionic Bonds
Polarity of Bonds Molecular Polarity. Equal Pull on Electrons If there is no difference in the electronegativity of the atoms forming a covalent bond,
Molecular Polarity AP Chemistry.
Polar vs. Non Polar Molecules. Covalent/Molecular Compounds All molecular compounds are either polar or nonpolar.
3.3 Polar bonds and Polar Molecules. Polar Bonds Polar covalent bonds have 0 < ∆En < 1.7 ∆En = 0Pure covalent 0 < ∆En < 0.4Slightly polar 0.5 < ∆En
Polar Covalent Bonds Electron pairs in covalent bonds are not always shared equally This affects the properties of the compound Remember electronegativity?
Molecular Polarity Boiling point = 100 ˚C Boiling point = -161 ˚C
Polar Bonds and Molecules
POLARITY.
Section 5.4—Polarity of Molecules
VSEPR and Polarity. Since all atoms have different electronegativities, a “ ” for the electrons in a bond begins when atoms bond. Since all atoms have.
Polarity Bonds and molecules. Types of bonds Ionic bonds occur when an atom of low ionisation energy loses valence electrons to an atom of high ionisation.
Aim: What are polar bonds and polar molecules?
HW: Read pages Draw the Lewis structure, write the formula, and indicate the shapes for the following compounds: Silicon tetrabromide Hydrogen.
Polarity How does electronegativity affect the polarity of a covalent bond? How does the shape of a molecule affect the polarity of a molecule?
Intermolecular Forces. How are molecules held together? There are two types of attraction in molecules: ◦ Intramolecular forces ◦ Intermolecular forces.
Unit 10: Chemical Bonding Section 1: Ionic and Covalent Bonding.
Polarity Chapter 6.1. Review A covalent bond is formed between two non-metals. Electrons are shared. Orbitals are overlapping.
COVALENT BONDING Hold on to your electrons!. What is a covalent bond? Atoms ___________ one or more electrons with each other to form the bond. Each atom.
Section 12.1 Characteristics of Chemical Bonds 1.To learn about ionic and covalent bonds and explain how they are formed 2.To learn about the polar covalent.
Bond Polarity Connecting to you Snow covers approximately 23% of Earth’s surface. Each individual snowflake is formed from as many as 100 snow crystals.
POLARITY AND SOLUBILITY: “Like dissolves like”. Review of shapes: What are the five basic shapes?  Linear  Trigonal Planar  Tetrahedral  Trigonal.
Polarity. Polar Covalent Remember ionic bonds transfer electrons, while covalent bonds share electrons. All atoms do not attract their electrons in a.
Chemistry Brodersen 2013/2014. Polarity in a molecules determines whether or not electrons in that molecule are shared equally. When determining the polarity.
Polar Bonds and Molecules (8.4) Bond Polarity Bond polarity has to do with unequal distribution of shared electrons This causes one end of the bond to.
IIIIII II. Molecular Geometry Ch. 9 – Molecular Structure.
Valence Shell Electron Pair Repulsion Theory –Electron pairs orient themselves in order to minimize repulsive forces.
Stability in bonding In covalent bonds, electrons aren’t always shared equally between the two nuclei. This is because some elements have a greater affinity.
Aim: What are polar bonds and polar molecules? Polar and Nonpolar Bonds There are two types of covalent bonds Nonpolar Covalent Bonds (equal share of.
Ionic & Covalent Bonding Electronegativity & Polarity.
EXAMINING POLARITY. MICRO-TO-MACRO We have studied the shapes and structures of molecules The shape of a molecule affects how that molecule behaves The.
Covalent Bonding ● Covalent bond – Bonds between two nonmetals. Electrons are shared, rather than transferred. ● Electronegativities are not strong enough.
Section 9.5 Electronegativity = ? –Ability to attract electrons When atoms react, the electronegativity between atoms will determine which type of bond.
 shared bonding electrons pairs are pulled (as in a “tug-of-war”) between atoms  results in an equal or unequal sharing.
Molecular Compounds Polarity.
6.7 Electronegativity and Bond Polarity
Molecular Polarity AP Chemistry.
Shapes of Molecules and Bonding
Chemical Bonding.
Bonds & Polarity Review:
CHEMICAL BONDING Cocaine Chemistry I – Chapter 8
Bond Polarity and Molecular Geometry
Chapter 10 Molecular Structure: Liquids and Solids
Polar vs. Non-Polar Molecules
Electronegativity and Polarity
Notes: 9.5 OBJECTIVES: Students will be able to (SWBAT)
Polar Bonds and Molecules Chapter 8.4
Polar Molecules Section 3.3.
Polar and Nonpolar Cl H -Electronegativity is the ability of an atom to pull or attract electrons shared between two atoms -An atom.
VSEPR Model and the Resulting Shapes
Molecular Polarity Chemistry.
Electronegativity and Polarity
Electronegativity and Polarity
Essential Question: What are polar bonds and polar molecules?
Although all covalent bonds involve a sharing of one or more pairs of electrons between bonding atoms, most of the time this sharing is not equal. One.
What are polar bonds and polar molecules?
Aim: How to describe the polarity of bonds and molecules
Chapter 6 -1 Bond Polarity (p. 198 – 201)
VI. Polarity.
Electronegativity and Polarity
Bond Types / Polarity.
Polarity.
Polar versus Nonpolar.
Polarity.
Unit 9: Covalent Bonding
Electronegativity and Polarity
Presentation transcript:

Polarity – It exists in two forms Bond Polarity We looking at the difference in electronegativies between atoms to determine how they share their electrons. Evenly or Unevenly Molecule Polarity We are looking at all the atoms surrounding the center atom and determine if there is symmetry or not. Symmetrical or Asymmetrical

Bond Polarity  The difference in electronegativities affects how atoms bond together.  Using the electronegativity values, we can predict the type of bond that forms.  Although all covalent bonds involve the sharing of electrons, most of the time this sharing is not equal.

 If one atom has a higher electronegativity than the other atom, it “hogs” the shared bonded pair of electrons most of the time.  This type of covalent bond is known as a polar covalent bond.  Polar bonds mean NOT EVEN! SF

Electronegativity Difference If the difference in electronegativities is between: – 1.8 to 4.0: Ionic A big difference, so an element pulls an electron off another. – 0.4 to 1.7: Polar Covalent A moderate difference, so they have to share, but not evenly. – 0.0 to 0.3: Non-Polar Covalent A small difference, so they share, and share evenly. Example: NaCl Na = 0.8, Cl = 3.0 Difference is 2.2, so this is an ionic bond!

Bond Polarity HCl is POLAR because it has a positive end and a negative end. (difference in electronegativity) HCl is POLAR because it has a positive end and a negative end. (difference in electronegativity) Cl has a greater share in bonding electrons than does H. We draw a dipole moment showing how the shared electrons are being pulled. Cl has slight negative charge (-  ) H has slight positive charge (+  )

Bond Polarity “Like Dissolves Like” “Like Dissolves Like” – Polar dissolves Polar – Nonpolar dissolves Nonpolar

Polarity of Whole Molecule  Determining the polarity of a bond is easy, but what about the molecule as a whole?  Strangely enough, you can have nonpolar molecules that contain polar bonds!  SO….  How do you determine if a molecule itself is going to be polar or nonpolar?  Look at the Lewis Structure and check out the central atom!

Determining if a Molecule is Nonpolar or Polar Look at what is attached to the central atom If every attached structure is the same The molecule is perfectly symmetrical And therefore NONPOLAR If the attached structures are different The molecule is asymmetrical And therefore POLAR

H δ+δ+δ+δ+ δ -δ -δ -δ - Polar Bond Br Asymetrical Polar Molecule

OCO== δ +δ +δ +δ + δ +δ +δ +δ + δ -δ -δ -δ - δ -δ -δ -δ - Polar Bonds However, the shape is symmetrical So… The molecule is nonpolar

Br Br Nonpolar Bond Symmetrical Nonpolar Molecule