MTPDF4 Chemical Bonding Concepts PDF

Chemistry for Engineers 1 CHEMICAL BONDING CONCEPTS MPS Department  FEU Institute of Technology  OBJECTIVES ∎ Define chemical bonds and the Lewis dot structure. ∎ Illustrate the Lewis Dot Structures. ∎ Determine maximum number electrons in a bond. ∎ Illustrate the bond...

Chemistry for Engineers 1 CHEMICAL BONDING CONCEPTS MPS Department  FEU Institute of Technology  OBJECTIVES ∎ Define chemical bonds and the Lewis dot structure. ∎ Illustrate the Lewis Dot Structures. ∎ Determine maximum number electrons in a bond. ∎ Illustrate the bond formation of the different types of chemical bond.  Chemistry for Engineers 1 Chemical Bond MPS Department  FEU Institute of Technology  Lewis Electron-dot Structures Lewis Structures – also known as electron-dot structures or Lewis electron-dot structures. – Example: Oxygen Chlorine https://www.clipartkey.com/view/mooJTx_oxygen- https://elearning.easygenerator.com/p dot-diagram-wiring-diagrams-lewis-electron-dot/ ublic/84516-Why-Do-Electrons- Matter/ Lewis Structure of Some Representative Elements http://www.lsua.us/chem1001/sampletest/01M3dfAnswer.htm  Chemical Bonds – electrostatic forces of attraction that hold atoms together. Valence Electrons – electrons in the outermost energy level of an atom. – determine what kind of chemical bonds the atom can form. https://www.docsity.com/en/news/education-2/types-chemical-bonding-presented-gifs/  How many Valence Electrons does each atom have? Gallium and Arsenic https://commons.wikimedia.org/wiki/File:Elect https://commons.wikimedia.org/wiki/File:El ron_shell_031_Gallium_-_no_label.svg ectron_shell_033_Arsenic_-_no_label.svg Valence Electrons of Elements  Valence Electrons of Elements No. of Valence Element Electronic Configuration Electrons Na 1 [Ne]3s1 Mg 2 [Ne]3s2 Al 3 [Ne]3s23p1 Si 4 [Ne]3s23p2 P 5 [Ne]3s23p3 S 6 [Ne]3s23p4 Cl 7 [Ne]3s23p5 Ar 8 [Ne]3s23p6 K 1 [Ar]4s1 Ca 2 [Ar]4s2 Recall: Electrons in each Energy Levels http://rogersphysicalscience.weebly.com/chem istry-facts-for-the-exam.html  Bond Formation Octet Rule - elements tend to combine in such a way that each atom has eight electrons in its valence shell giving it the same electron configuration as a noble gas (exception: Hydrogen with 2 max electrons in its outershell). - Alteration of electron configuration: - Metal loses 1 to 3 electrons to form a cation. - Non Metals gain 1 to 3 electrons to form an anion. - Atoms (2 non metals) share electrons with other atoms.  Ionic Bonds – form from the electrostatic attraction between oppositely charged ions. – there is transferring of electrons. – atoms become ionic by losing or gaining electrons from the atom it is bonding with. https://www.daviddarling.info/encyclopedia/I/ionic_bond.html  Metallic Bond – Metals can form bonds with other metals, but it is neither covalent or ionic and they cannot share electrons to form an octet of electrons around each atom. – The valence electrons are delocalized, which means they are free to move from one atom to the next. https://simple.wikipedia.org/wiki/Metallic_bond Metallic Bond https://commons.wikimedia.org/wiki/File:Lotu ra_metalikoko_elektroi-hodeia..gif  Covalent Bonding – bonds between atoms which are formed through sharing of electrons. – between two non-metal atoms through sharing of pairs of electrons https://www.docsity.com/en/news/education-2/types-chemical-bonding-presented-gifs/  Covalent Bonding EXAMPLES: Nitrogen Fluorine https://www.quora.com/What-type-of-bond- https://mrosechemistry.weebly.com/uploads/2 forms-when-two-atoms-of-nitrogen-join-to- /7/5/8/27587455/21_chemical_bonding_revie form-a-nitrogen-molecule w.pdf Chlorine Bromine https://www.seastarchemicals.com/products- http://a.2002-acura-tl-radio.info/page- services/trace-metal-analysis- b/electron-dot-diagram-for-cl2-89294.html products/baseline-bromine/  Polar & Non Polar Covalent Bonding Non polar Bond – have an equal attraction or affinity for electrons. e.g. H2, N2, Cl2, Br2 Polar Bond – formed when electrons are unequally shared between two atoms. e.g. H2O, HF, NH3  Chemistry for Engineers 1 Covalent Bond MPS Department  FEU Institute of Technology  OBJECTIVES ∎ Define chemical bonds. ∎ Determine maximum number electrons in a bond. ∎ Differentiate the bond formation as Ionic, Metallic, and Covalent.  Single, Double and Triple Bond Single Bond – sharing of a pair of electrons between two atoms. Examples: HF, Cl2, H2O Double Bond – sharing of 2 pairs of electrons between two atoms. Examples: O2, CO2 Triple Bond – sharing of 3 pairs of electrons between two atoms. Examples: N2, HCN  Writing Lewis Structure Write the Lewis Structure H2O – Step 1: Find the total number of valence electrons. Total = 6e x 1 atom O + 1e x 2 atom H = 8 – Step 2: Draw the skeletal structure. H O H H:O:H – Step 3: Subtract the 4 electrons used in Step 2 from 8, to obtain 4 electrons to be placed. – Step 4: Place the 2 electrons (lone pair or nonbonding pair) around the O atom. H:O:H  Try this! Write the Lewis Structure of Following 1. HCl 2. H2 S 3. CO2 4. Cl4 5. HNO3  Electronegativity & Bond Polarity Electronegativities can be used to predict the nature of the bond. Generally, if the electronegativity difference is: 0.0 – 0.4 non polar covalent bond 0.4 – 1.78 polar covalent bond 1.78 > ionic bond https://wou.edu/chemistry/courses/online-chemistry-textbooks/ch103-allied-health- chemistry/ch103-chapter-5-covalent-bonds-organic-functional-groups-and-biological- molecules/  What type of bond is created? Determine the type of bond of the following a) NaF b) FrBr c) CN d) SeS e) BrO THANK YOU… GOD BLESS…  REFERENCES Lawrence S. Brown and Thomas A. Holme (2018), Chemistry for Engineering Students : Cengage Learning Roxy Wilson (2018), Solutions to Red Exercises: Chemistry: The Central Science : United Kingdom: Pearson Theodore E. Brown, et. al.(2018), Chemistry: The Central Science (14th Edition) : United Kingdom: Pearson https://www.chem.purdue.edu/vsepr/practice.html https://www.dimanregional.org/site/handlers/filedownload.ashx? moduleinstanceid=8493&dataid=3065&FileName=Lewis%20Pra ctice.pdf https://courses.lumenlearning.com/trident-boundless- chemistry/chapter/types-of-chemical-bonds/ https://www.slideshare.net/sonikhan3/covalent-bond-58860132