Day 3 Handout Electronegitivity Bond Polarity and Molecular polarity PDF

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Summary

Just a worksheet, that discusses types of electronegativity bonds polarity and molecular polarity. There's a lot of useful problems that helped and were on my exam...

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4.3 Electronegativity Bond Polarity Key Terms ● Non-Polar Covalent: a covalent bond where the electrons are shared equally between atoms ● Polar Covalent Bond: a covalent bond where the electrons are not shared equally because one atom attracts them stronger than the other atom. ● 

Electronegativity ● The ability of an atom in a molecule to attract electrons to itself. ● It can be seen that electronegativity increases across periods on the periodic table. ○ 

 ● Electronegativity in relation to bond type ○ Electronegativity: 1.7 Bond type: ionic Character: ionic

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Bond Polarities and Dipoles in Diatomic Molecules ● Dipoles: a separation of positive and negative charges in a region/place in space ● For example, hydrogen fluoride has a specific orientation in which the distribution is drawn to one side of the molecule ○        

 Using Electronegativity Values to Determine Bond Polarity 1. These will most likely be asked to be given in order of most to least polar or vice versa.  2. You will be given 2 elements which are bonded 3. Find their electronegativity 4. Then subtract the larger from the smaller. a. The difference is the electronegativity of the molecule For example. . . H-H, O-H, Cl-H, S-H, F-H, in order of decreasing predicted bond polarity. The general formula is . . . ENx-y=ENx-ENy  H-H= 2.1-2.1 S-H=2.5-2.1 =0 =0.4   O-H=3.5-2.1 F-H=4-2.1 =1.4 =1.9   Cl-H=3-2.1 In order F-H, O-H, Cl-H, S-H, H-H =0.9      

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 4.5 Molecular Polarity Polar and Non-Polar Polyatomic Molecules ● So far you should know that molecules can become polar when they have significantly different electronegativities.  ● Fairly symmetrical VSEPR shapes have polar bonds with no net dipole. ○ Linear with 2 identical bonds ○ Planar with 3 identical bonds ○ Tetrahedral with 4 identical bonds 

Key Terms ● Polar molecule: A molecule that has a net dipole. (which is almost like an average for direction)  ● Non-Polar Molecule: A molecule that has only nonpolar bonds or a dipole sum of zero.  

Predicting Polarity of Molecules 1. 2. 3. 4.

Draw a simplified lewis structure diagram Use VESPR Theory to predict the structure Identify the electronegativity for each atom Draw the direction of the bond dipoles according to which has a higher electronegativity. ● For example, CF4 following the laid out steps  ● 

    ●       ●   

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    4.3 Electronegativity Bond Polarity 

Youtube Video on Bond Polarity for Extra Help https://youtu.be/PVL24HAesnc 

Text Book Homework Page 221, numbers 1 to 6 Answers are provided at the back of the book. 

    4.5 Molecular Polarity 

Youtube Video on Molecular Polarity for Extra Help  https://youtu.be/cpWHgKgKxGk 

Text Book Homework Page 229, numbers 1 to 7 Answers are provided at the back of the book. 

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