Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

1. A Review of General Chemistry

Formal Charges

Organic Chemistry

1. A Review of General Chemistry

Formal Charges

Previous problemNext problem

3:15 minutes

Problem 30a

Textbook Question

Calculate the formal charge of the indicated atoms in the ions shown.

Verified step by step guidance

Step 1: Recall the formula for calculating formal charge: Formal Charge = (Valence Electrons) - (Non-bonding Electrons) - (1/2 × Bonding Electrons). This formula helps determine the charge on an atom within a molecule or ion.

Step 2: Identify the atom whose formal charge needs to be calculated and determine the number of valence electrons it has based on its position in the periodic table. For example, carbon has 4 valence electrons, oxygen has 6, etc.

Step 3: Count the number of non-bonding electrons (lone pairs) around the atom. These are electrons that are not involved in bonding and are directly associated with the atom.

Step 4: Count the number of bonding electrons (shared electrons in bonds) around the atom. Since each bond consists of two electrons, divide the total bonding electrons by 2 to account for the atom's share.

Step 5: Substitute the values into the formal charge formula and simplify to determine the formal charge of the indicated atom. Repeat this process for each atom in the ion as needed.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Formal Charge

Formal charge is a theoretical charge assigned to an atom in a molecule, calculated based on the number of valence electrons, the number of non-bonding electrons, and half the number of bonding electrons. It helps in determining the most stable structure of a molecule by minimizing the formal charges across the atoms. The formula is: Formal Charge = Valence Electrons - (Non-bonding Electrons + 1/2 Bonding Electrons).

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They provide a visual way to understand the arrangement of electrons and the connectivity of atoms, which is essential for calculating formal charges. Drawing accurate Lewis structures is the first step in determining the formal charge of specific atoms.

Ionic Species

Ionic species are atoms or molecules that have gained or lost electrons, resulting in a net charge. Understanding the nature of these ions is crucial when calculating formal charges, as the charge affects the distribution of electrons in the Lewis structure. Recognizing whether an ion is positively or negatively charged helps in applying the formal charge formula correctly to the indicated atoms.

Watch next

Master Calculating formal and net charge. with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

Draw the Lewis structure for the following molecules. Be sure to calculate the formal charge of each atom as a way of confirming your structure is correct.

(b) HOBr

Textbook Question

Calculate the formal charge of the indicated atom in the following molecules or ions.

(d)

Textbook Question

Draw the Lewis structure for the following ions. Be sure to calculate the formal charge of each atom to confirm that your structure is correct.

(b) H⁺

Textbook Question

Draw the Lewis structure for the following ions. Be sure to calculate the formal charge of each atom to confirm that your structure is correct.

(d) AlCl₄^-

Textbook Question

Calculate the formal charge on the non-hydrogen atoms in the molecules shown. Use the arrow-pushing formalism to 'move' an electron pair such that it is shared between two (formerly) charged atoms. Your arrow should account for the formation of the molecule on the right from the molecule on the left.

Textbook Question

Looking ahead in Chapter 3, we describe how the formal charge on an atom can be used to predict the number of lone pairs. Given the charge, or lack of charge, on each atom, fill in the electron pairs.

(a)

Textbook Question

Based on the formal charge, determine how many lone pairs are on each indicated atom.

(a)

Textbook Question

Give each atom the appropriate formal charge:

Show more practices

Download the Mobile app

Privacy

Do not sell my personal information

Accessibility

Patent notice

Sitemap