Day 2 Notes--Bond Polarity COMPLETE.notebook

Day 2 NotesBond Polarity COMPLETE.notebook March 09, 2020

Daily Quiz 3/9/202075.

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77.

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RemindersACT Makeups Tuesday, 3/10

Quarter 3 Test 3/17

World Language Spirit Week:

Today Olympic Day

Tomorrow World Flag Day

Wednesday Tacky Tourist Day

Thursday Famous Person Day

Friday World Language TShirt Day

Meg Jenkins Color Run Friday (3/13)

Objectives and Indicators

1. Classify chemical bonds as ionic, polar covalent, or nonpolar covalent based on electronegativity differences.2. Explain how hydrogen bonding affects the physical and chemical properties of water.3. Compare the properties of molecules with and without hydrogen bonding.

• H.C.3A.4: Plan and conduct controlled scientific investigations to generate data on the properties of substances and analyze the data to infer the types of bonds—ionic, polar covalent, and nonpolar covalent.

• IV.4.f: Describe the relationship between bond polarity and molecular polarity.

Non‐polar Covalent BondSharing of bonding electron pair is equal between the atoms

Nonpolar = "dipole moment of zero"

7 diatomic molecules that are NON‐POLAR: Br2, H2, O2, N2, Cl2, I2, F2

Sometimes called BrINClHOF

Polar Covalent Bonding

• One atom in the bond has a higher EN value for electrons• This atom pulls/attracts shared electron pair with greater force• Results in UNEQUAL sharing• Atom that pulls harder is slightly ‐ (negative)• Atom that does not pull as hard is slightly + (positive)• Dipole: molecule with + and ‐ ends

e-

Electron Distribution in Ionic and Covalent Bonds

The terms POLAR and NONPOLAR can only be used with COVALENT BONDS!!!

You will NOT have a polar ionic bond!!!


How can you use electronegativity values to determine if a

bond is ionic, polar covalent, or nonpolar covalent???

How do you know if a MOLECULE is polar or nonpolar???

1. Draw the Lewis structure.2. Determine if the bonds are polar.3. See if the bond polarities will cancel out.

(Is it symmetrical?)4. Look for lone pairs of electrons.5. Determine if there is polarity.6. Draw the polarity arrow if it is there‐‐it will point to the MOST EN atom




Check for Understanding: Polar or Nonpolar Molecule?










Accept or refute this statement. Provide an example to support your answer.

If atoms of two elements with high electronegativies form a bond, the bond will most likely be classified as polar covalent.

1. NCl3

2. CF2H2

3. CH2O 4. CS2


5. H2O

Molecular Polarity POGIL

Pay AttentionThere are 2 terms that we are getting ready to discuss that sound very similar, but have completely different meanings. Make sure you are communicating the right term at the right time. Intramolecular ForceGorilla Glue

• Ionic or covalent BONDS• Attractive forces between ions or

atoms within a compound• Relatively strong• Takes a lot of energy to break a

bond• 4000 kJ ionic compounds• 1100 kJ covalent compounds

Intermolecular ForceElmer's Glue

• Attractive forces between molecules• Strength is weaker than ionic or

covalent bond• Responsible for the state of matter at

room temperature• Amount of energy to overcome

intermolecular forces> 0.0540 kJmatter without ions> 600 kJmatter with ions

Types of IMFs

London Dispersion ForcesDipoledipole interactionsHydrogen bondingIon dipole interactions

Animations for IMFshttps://www.wisconline.com/learn/naturalscience/chemistry/gch6804/intermolecularforces

temporary or momentary dipoles

As the molecular mass of a compound increases, there are more electrons present so strength of LDF is GREATER!

https://www.wisc-online.com/learn/natural-science/chemistry/gch6804/intermolecular-forces


Gas liquid

solidWhy ?

http://virtuallaboratory.colorado.edu/CLUEChemistry/LondonDispersionForce/1.2interactions0.html

permanent dipoles

Both of these are POLAR MOLECULES!

Hydrogen Bonding

• Definition> Attraction between hydrogen covalently bonded

to N, O, or F in one molecule to the lone electron pairs of N, O, or F in another molecule.

• Just because a molecule contains H does NOT mean that there is hydrogen bonding!

• Relative Strength: Moderate

• Physical Properties> WATER is a GREAT example> Mostly liquids> High boiling points> Surface tension> Adhesion and cohesion

http://virtuallaboratory.colorado.edu/CLUE-Chemistry/LondonDispersionForce/1.2-interactions-0.html


IonDipole Intermolecular Forces of Attraction

• Type of attraction between an ion and the oppositely charged end of a dipole

• This type of attraction is extremely important when you are talking about dissolving an ionic solute in water>this is important to your life!

Opening Questions: Monday, Feb 26th

The pictures above show how electrons in a bond are distributed between the electron clouds of two bonded atoms, A and B.

1. Explain the type of bond present in each picture.

2. Why is atom A smaller in the second and third pictures?

3. What is electronegativity and how does it apply to the pictures?

4. Which atoms could be considered partially negative? partially positive?

Review of Essential Concepts

Do you understand these terms

electronegativity

ionic bond, polar covalent bond, nonpolar covalent bond

Practice

Bonding BINGO

• Read the question on the index card. • Answer in the indicated space on your bingo card.• Bring your card to the front and trade it out for another one.• Repeat• Once you have answered 5 questions in a row, you have BINGO! Bring your bingo card to me to be checked. Win a prize for every bingo you earn.

• At the end of the period, ALL index cards need to be returned to the front counter.

• Give me your bingo card. We will play again tomorrow as part of review for your quiz.

• You need to turn in the Independent Practice part of yesterday's handout tomorrow. This will be graded.

DUE TOM

ORROW!

Graded fo

r ACCUR

ACY!

Great wa

y to stud

y for

your quiz

!


Documents

Day 2 Notes--Bond Polarity COMPLETE.notebook