covalent (molecular) bonds
DESCRIPTION
Covalent (Molecular) Bonds. Covalent (Molecular) Bond Definition Covalent –“sharing, valence electrons” Non-metals bonded to non-metals Bond based on shared electrons between two atoms Forms a molecule (hence the name). Covalent (Molecular) Bond Properties. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/1.jpg)
Covalent (Molecular) Bonds
![Page 2: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/2.jpg)
Covalent (Molecular) Bond Definition• Covalent –“sharing, valence electrons”
• Non-metals bonded to non-metals
• Bond based on shared electrons between two atoms
• Forms a molecule (hence the name)
![Page 3: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/3.jpg)
Covalent (Molecular) Bond Properties
• Very strong bond, however often not a strong force of attraction between molecules.
• As a result molecular compounds have the lowest melting/boiling points
![Page 4: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/4.jpg)
Types of Covalent Bonds• Single- one shared pair of e-
• Double- two shared pairs of e-
• Triple- three shared pairs of e-
Strength: 3>2>1
Q:How do you know what types will form?
A:Use VSEPR!
![Page 5: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/5.jpg)
Drawing Covalent Bonds using V.S.E.P.R.Valence Shell Electron Pair Repulsion
According to VSEPR theory, the repulsion between electron pairs causes molecular shapes to adjust so that the valence-electron pairs stay as far apart as possible.
-Like repels like (+ repels +)(- repels -)
![Page 6: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/6.jpg)
VSEPR Steps:• Place either the single element or the C in
the middle and arrange the others around it
• Draw the Lewis Dot Diagram for each element
• Draw a line connecting the valence electrons to represent one pair of electrons until each element fulfills the octet rule
![Page 7: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/7.jpg)
Single Bond Example #1
• F2
-Group 17 diatomic molecules are single bonds and formed this way!
![Page 8: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/8.jpg)
Single Bond Example #2
• H2O
![Page 9: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/9.jpg)
Single Bond Example #3
• CH4
![Page 10: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/10.jpg)
Double Bond Example #1
• CO2
![Page 11: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/11.jpg)
Double Bond Example #2
• NO
![Page 12: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/12.jpg)
Triple Bond Example #1
• N2
![Page 13: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/13.jpg)
Triple Bond Example #1
• HCN
![Page 14: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/14.jpg)
On notebook paper, use VSEPR to draw the following:
Carbon tetrachloride (CCl4)
Ammonia (NH3)
Water (H2O)
Nitrogen (N2)
Hydrogen (H2)
Phosphorous trichloride (PCl3)
Carbon dioxide (CO2)
Ethyne (C2H2)
![Page 15: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/15.jpg)
Carbon tetrachloride (CCl4)
Ammonia (NH3)
![Page 16: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/16.jpg)
Water (H2O) Nitrogen (N2)
N N______..
. ..
![Page 17: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/17.jpg)
Hydrogen (H2) Phosphorous trichloride (PCl3)
H H__
![Page 19: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/19.jpg)
Drill
Decide whether each substance is composed of covalent or ionic bonds.
1. Methane CH4 2. Carbon Dioxide CO2
3. Potassium Bromide KBr
![Page 20: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/20.jpg)
Naming Covalent Bonds
![Page 21: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/21.jpg)
Steps to Naming Covalent Bonds
• Write name of first element– Use prefix if there’s more than 1
• Write name of second element, changing ending to “ide”– Use prefix always
![Page 22: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/22.jpg)
Prefixes1 mono-2 di-3 tri-4 tetra-5 penta-6 hexa-7 hepta-8 octa-9 nona-10 deca-
![Page 23: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/23.jpg)
Practice
1. NCl3 2. N2H4
3. CS2 4. N2O3 5. Cl2O7
6. S2F10
7. Cl4
![Page 24: Covalent (Molecular) Bonds](https://reader035.vdocuments.mx/reader035/viewer/2022062305/568164aa550346895dd6a936/html5/thumbnails/24.jpg)
Practice-ANSWERS
1. NCl3 Nitrogen trichloride
2. N2H4 dinitrogen tetrahydride
3. CS2 carbon disulfide
4. N2O3 dinitrogen trioxide
5. Cl2O7 dichlorine heptoxide
6. S2F10 disulfur decafluoride
7. Cl4 tetrachloride