Formal charges provide a simple method to estimate charge distribution within ions and molecules using integer charges assigned to each atom. The procedure involves drawing Lewis structures, determining the group number, unshared electrons, and bonded electrons for each atom to calculate its formal charge. Common patterns show atoms of the same element in a structure usually have the same formal charge, and structures aim to minimize the number of atoms with formal charges other than 0, +1, or -1. While only an estimate, formal charges can predict reactivity and properties by indicating which atoms are most electron rich or deficient.
A recently updated portfolio of my work produced for up and coming job interviews and to decorate coffee tables. Mainly focusing on branding, layout and illustrations.
CH 4 CHEMICAL BONDING AND MOLECULAR STRUCTURE.pdfLUXMIKANTGIRI
English chapter we will discuss about bonding how the molecules and the ions are in texting as a molecule make the structure there energy their transmission and other
For Chem 1:
Significanceof the ELectron in Bonding
The Octet Rule
Lewis Symbol/Structures
Formal Charge
Polyatomic Ions
Types of Bonds (Ionic, Covalent, Coordinate Covalent, Metallic Bonds, Multiple Bonds)
Exceptions to the Octet Rules
Oxidation Number is not included in the class discussion and exam. ;D
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Unit 8 - Information and Communication Technology (Paper I).pdf
Formalcharge
1. Formal Charges
Discussion: Ions bear a positive or negative charge. If the ion is polyatomic (is
constructed of more than on atom), we might ask which atom(s) of the ion carry the
charge? Knowledge of charge distribution (identification of atoms that are electron rich
or electron poor) can be useful to interpret many facets of organic chemistry, including
how and why reactions occur (mechanisms) or how molecules interact with each other, a
feature which strongly influences physical and biological properties.
Valence electrons do not "belong" to any one atom in a molecule or ion. Quantum
mechanics tells us that electrons are shared by a few neighboring atoms, or even by the
whole molecule. Because atoms differ in electronegativity and hybridization, it is
inaccurate to assume that these electrons are shared equally. (The rare exception is a pure
covalent bond between two identical atoms such as in molecular chlorine, Cl–Cl.)
Because of this uneven sharing atoms have fractional, rather than integer, charges.
Calculations to determine exact electron distribution and atomic charges require complex
computer programs and often many hours of computer time. Chemists need a way to
rapidly estimate the electron rich and electron poor sites of a molecule or ion to allow a
rough estimate of chemical and physical properties.
Chemists have developed a very simple bookkeeping method to determine if an atom
within a molecule or ion is neutral, or bears a positive or negative charge. The method
provides integer charges only. Because this method provides some indication of charge
distribution, it is an excellent starting point for determining electron distribution within a
molecule or ion, and hence give us a starting point to predict chemical and physical
properties. These assigned integer charges are called formal charges. A formal charge is a
comparison of electrons "owned" by an atom in a Lewis structure versus the number of
electrons possessed by the same atom in its unbound, free atomic state.
Procedure: The procedure to determine formal charges on the atoms of an ion or
molecule has three steps. The process is illustrated using hydronium ion (H3O+
); an ion
very frequently encountered in organic and biochemical reaction mechanisms.
Step 1: Draw the best Lewis structure for the molecule, including all unpaired
electrons. Be sure to show all nonbonded electrons, as these influence formal charges.
The best Lewis structure for the hydronium ion is shown below. The brackets indicate the
positive charge belongs to the entire molecule.
Step 2. Assign the formal charge to each atom. Formal charge is calculated using this
formula:
H O H
H
2. FC = GN - UE - 1/2 BE
Where: FC = formal charge
GN = periodic table group number (number of valence electrons in free,
nonbonded atom)
UE = number of unshared electrons
BE = number of electrons shared in covalent bonds.
Thus for hydronium ion:
The formal charge on hydrogen is calculated as follows. Hydrogen has one valence
electron (GN = 1), no unshared electrons (UE = 0) and two shared electrons in the
oxygen-hydrogen covalent bond (BE = 2). Thus the calculated formal charge on
hydrogen is zero. Because each hydrogen atom in this molecule is identical, each
hydrogen atom has the same formal charge of zero. Any hydrogen bearing one covalent
bond always has a formal charge of zero.
The formal charge on oxygen is calculated as follows. Oxygen has six valence electrons
(GN = 6), two unshared electrons in one lone pair (UE = 2), and six shared electrons in
three oxygen-hydrogen covalent bonds (BE = 6). Thus the calculated formal charge on
oxygen is +1. This indicates the oxygen atom bears the majority of the positive charge of
this ion.
Step 3. Check your work. The sum of the formal charges of all atoms must equal the
overall charge on the structure. For hydronium ion, the sum of the formal charges on the
hydrogen atoms (3 x zero) plus one for the oxygen gives a total charge of +1, which
agrees with the overall charge.
After you practice this procedure with a few structures, you will begin to notice patterns
in formal charge distribution. Becoming familiar with these patterns will help you avoid
having the tedious task of calculating formal charge for every atom of every structure you
encounter.
Formal Charge Patterns
1. The best Lewis structure or resonance contributing structure has the least number of
atoms with formal charge.
2. Equivalent atoms have the same formal charge. For example, all the hydrogen atoms
of methane (CH4) are equivalent and therefore have the same formal charge. All six
hydrogens of ethane (H3C-CH3) have the same formal charge, as do the two carbon
atoms.
FC = 1 - 0 - 1/2(2) = 0
FC = 6 - 2 - 1/2(6) = +1
H O H
H
3. 3. Formal charges other than +1, 0 or -1 are uncommon except for metals.
4. The vast majority of organic structures are made up of a small set of atoms with a
limited number of bonding possibilities. Recognizing these cases will allow you to
avoid formal charge calculations most of the time, and speed your understanding of
how charge influences reactions and properties of molecules. These patterns are
summarized in the table below.
Formal Charge Patterns
Element FC = -1 FC = 0 FC = +1
Hydrogen Hydride ion H+ Naked proton
Never ever!
Carbon Carbanion Carbocation
Nitrogen Nitranion Ammonium
Oxygen Oxyanion Oxonium
Halogen
(X = F, Cl, Br, I)
Halide ion Halonium
Frequently Asked Questions
Question: What is the relationship between having full valence shells and formal
charges? Do full valence shells always result in a formal charge of zero?
Answer: Valence shell occupancy alone does not determine formal charge. The element
involved also matters. For example the full valence shell for carbon in methane (CH4)
results in a formal charge of zero for carbon, whereas the full valence shell for nitrogen in
the ammonium cation (NH4
+
) results in a +1 formal charge for nitrogen.
Exercises
Calculate the formal charge on each atom in the following Lewis structures.
1. Methoxide ion
H H
C C
open octet
C
N N
N
O O
O
X X X
H C
H
O
H
4. 2. Methyl carbocation
3. Tetrahydridoborate ion
4. An oxonium ion
5. Carbon monoxide
6. Sulfuric acid
7. Dimethyl sulfoxide
8. Ozone
9.
Nitromethane
Exercise Solutions
1.
All three hydrogen atoms are equivalent and therefore have the same charge
(neutral). The oxygen atom bears the bulk of the ion's negative charge. The sum
of the atomic charges = (3 x 0) + 0 + (-1) = -1 = charge on the ion.
2.
H C
H
H
H B
H
H
H
C
H
H
O H
C O
H O S
O
O
O H
H C
H
H
S
O
C
H
H
H
O O O
H C
H
H
N
O
O
FC = 6 - 6 -1/2(2) = -1
FC = 4 - 0 - 1/2 (8) = 0
FC = 1 - 0 - 1/2 (2) = 0
H C O
H
H
FC = 1 - 0 - 1/2 (2) = 0
FC = 4 - 0 - 1/2 (6) = +1H C
H
H
5. All three hydrogen atoms are equivalent and therefore have the same charge
(neutral). The carbon atom bears the bulk of the ion's positive charge. The sum of
the atomic charges = (3 x 0) + (+1) = +1 = charge on the ion.
3.
All four hydrogen atoms are equivalent and therefore have the same charge
(neutral). The boron atom bears the bulk of the ion's negative charge. The sum of
the atomic charges = (4 x 0) + (-1) = -1 = charge on the ion.
4.
The two hydrogens attached to carbon are equivalent and therefore have the same
charge (neutral). The oxygen atom bears the bulk of the oxonium ion's positive
charge. The sum of the atomic charges = (2 x 0; C-H) + 0 (O-H) + 0 (C) + (+1; O)
= +1 = charge on the ion.
5.
Although the formal charge of the entire molecule is neutral, the carbon bears a
negative charge and the oxygen bears a positive charge. The sum of the atomic
charges = (-1) + (+1) = 0 = charge on carbon monoxide.
6.
All atoms have formal charges of zero, equal to the molecular charge of zero.
7.
FC = 1 - 0 - 1/2 (2) = 0
FC = 3 - 0 - 1/2 (8) = -1
H B H
H
H
FC = 1 - 0 - 1/2 (2) = 0
FC = 1 - 0 - 1/2 (2) = 0
FC = 6 - 2 - 1/2 (6) = +1
FC = 4 - 0 - 1/2 (8) = 0 C
H
H
O H
C O
FC = 4 - 2 - 1/2 (6) = -1
FC = 6 - 2 - 1/2 (6) = +1
H O S
O
O
O H
FC = 6 - 0 - 1/2 (12) = 0
FC = 6 - 4 - 1/2 (4) = 0
FC = 1 - 0 - 1/2 (2) = 0
FC = 6 - 4 - 1/2 (4) = 0
FC = 6 - 2 - 1/2 (8) = 0
FC = 6 - 4 - 1/2 (4) = 0
C S
O
C
H
H
H
H
H
H
FC = 1 - 0 - 1/2 (2) = 0
6. The six hydrogen atoms are all equivalent, so they all have the same formal
charge of zero. All atoms have a zero formal charge, in agreement with the
molecular charge of zero.
8.
The three oxygen atoms in this resonance structure for ozone are not equivalent,
because they have different numbers of oxygen-oxygen bonds and different
formal charges. The sum of the atomic charges = 0 + (+1) + (-1) = 0 = molecular
charge.
9.
The three hydrogen atoms are equivalent and thus have the same neutral charge.
The oxygen atoms do not have the same bond order with the nitrogen, so these
oxygen atoms are not equivalent. The sum of the atomic charges = 3 x 0 (for the
hydrogens) + 0 (for the carbon) + (+1 for the nitrogen) + (0 for the double bonded
oxygen) + (-1 for the single bonded oxygen) = 0 = molecular charge. Although
the molecule is neutral, the nitrogen and one of the oxygens carry charge.
FC = 6 - 6 - 1/2 (2) = -1FC = 6 - 4 - 1/2 (4) = 0
FC = 6 - 2 - 1/2 (6) = +1
O O O
FC = 1 - 0 - 1/2 (2) = 0
FC = 4 - 0 - 1/2 (8) = 0
FC = 6 - 4 - 1/2 (4) = 0
FC = 5 - 0 - 1/2 (8) = +1
FC = 6 - 6 - 1/2 (2) = -1
N
O
O
C
H
H
H