CHEMDUNN

This episode explains resonance, where a molecule cannot be accurately represented by a single Lewis structure. Resonance occurs when multiple valid Lewis structures can be drawn by moving only electrons, not atoms. The real molecule is a resonance hybrid, a blend of all possible structures. This electron delocalization leads to increased molecular stability and identical bond lengths that are an...

This episode discusses three exceptions to the octet rule : incomplete octets (e.g., boron in BF3), odd electron species with an unpaired electron (e.g., NO), and expanded octets (e.g., sulfur in SF6). It explains that atoms in period 3 and beyond can have expanded octets due to available d orbitals. It emphasizes that while most molecules follow the rule, these exceptions are predictable based on...

This episode classifies compounds into three types based on their chemical bonds: ionic, covalent, and metallic. Ionic compounds, formed by electron transfer, are brittle with high melting points and conduct electricity when molten. Covalent compounds, formed by electron sharing, have lower melting points and poor conductivity, with the exception of network covalent materials. Metallic compounds,...

This episode provides a six-step guide to drawing Lewis structures , diagrams that show how valence electrons are arranged in molecules. It explains how to count electrons, identify a central atom, and connect atoms with single or multiple bonds to satisfy the octet rule . Using examples like water and carbon dioxide, it walks through the process and point out common errors. The episode stresses t...

This episode explains UV-Vis spectroscopy, an analytical technique that measures how much ultraviolet and visible light a substance absorbs. It describe how the instrument works, its main components, and the Beer-Lambert Law (A=ɛbc), which shows that a sample's absorbance is directly proportional to its concentration. It also explains how to use this principle to calculate unknown concentratio...

This episode explains that an atom's or molecule's magnetic behavior, either diamagnetism or paramagnetism, is determined by its electron configuration. Diamagnetism is present in all substances with paired electrons, resulting in a weak repulsion from magnets. Paramagnetism occurs in substances with unpaired electrons, which are attracted to magnets. It explains how to predict a substance...

This episode explains that quantum numbers are a set of four values that serve as a unique address for every electron. The Pauli exclusion principle states that no two electrons can have the same four quantum numbers. The four numbers are: n (principal, for energy level), l (angular momentum, for orbital shape), ml​ (magnetic, for orbital orientation), and ms​ (spin, for electron direction). These...

This episode defines electron configuration as the arrangement of electrons in an atom's orbitals. It explain two notation methods: standard notation (e.g., 1s2) and orbital box notation, and outlines the three fundamental filling rules: the Aufbau principle, Pauli exclusion principle, and Hund's rule. It introduce noble gas shorthand for larger atoms and discuss notable exceptions like ch...

Think of an electron's path around an atom. If you're imagining a planet orbiting the sun, think again! In this episode, we're diving into the strange and fascinating world of atomic orbitals. We'll explain why electrons don't follow neat, predictable paths and instead inhabit "probability clouds." You'll learn the unique shapes of the four main types of orbitals—...

This episode dives into the predictable patterns of the periodic table, or "atomic trends," that help us understand how elements behave. It explains how properties like atomic radius (the size of an atom), electronegativity (its attraction for electrons), and ionization energy (the energy required to remove an electron) change as you move across a period or down a group. By breaking down...

Every element has a unique identity, but what about its different "versions"? In this episode, we're cracking the code of isotopic notation, the shorthand chemists use to describe an atom's specific makeup. You'll learn how to read and write these symbols, understanding what the atomic number (the number of protons) and the mass number (protons plus neutrons) tell us about an...

Ever need to convert miles to feet or milliliters to gallons? Dimensional analysis, also known as the factor-label method, is your secret weapon! In this episode, we're demystifying this powerful technique that allows you to solve complex conversion problems with ease. We'll show you how to set up problems using conversion factors to cancel out units, transforming a seemingly difficult mat...

Ever wonder why two words that seem so similar are so different to a scientist? In this episode, we're drawing a clear line between accuracy and precision, two critical concepts in every lab and experiment. We'll use a simple analogy—like throwing darts at a dartboard—to show you the difference between getting a result that's close to the true value (accuracy) and getting consistent, r...

Ever stared at a number with a dozen zeros and felt your head spin? That’s where scientific notation comes in! In this episode, we're unraveling the genius of this mathematical tool that chemists use every day. We'll show you how to easily convert massive numbers (like the distance to the sun) and tiny ones (like the size of an atom) into a simple, compact format. We'll break down the...

What makes a bowling ball sink and a beach ball float? The answer is density! In this episode, we're unlocking one of chemistry's properties. We'll demystify what density truly is—a measure of how much 'stuff' is packed into a given space. You'll learn the simple formula (density = mass/volume) and discover how it explains why some objects are heavy for their size while oth...

Everything you see, touch, and even breathe is matter. But how do scientists organize and understand the vast variety of substances in the universe? In this episode, we're tackling the classification of matter. We'll journey through the basic building blocks, from elements to compounds, and explore the difference between a pure substance and a mixture. We'll also break down the two mai...

Ready to master the art of chemical mixing? In this episode, we're stepping into the lab to show you how to accurately and safely prepare a solution. From understanding the difference between a solute and a solvent to using a volumetric flask, we'll walk you through the essential steps that chemists use every day. We'll cover everything from simple dilutions to creating a solution with...

Join us on this episode as we dive deep into the world of molarity, a fundamental concept in chemistry that's way more than just a fancy word. Have you ever wondered how scientists precisely measure the concentration of a solution? Or what makes one acid stronger than another? Molarity is the key! We'll break down the basics, from moles and liters to the simple formula that unlocks a unive...

This episode explains the fundamental principles of collision theory, stating that molecular collisions are necessary for reactions to occur, and that both proper orientation and sufficient energy are required for effective collisions. It introduces the concept of activation energy, the minimum energy needed for a reaction, and the unstable transition state formed during a successful collision. Fi...

This episode explains the concept of limiting reactants in chemical reactions. It uses the analogy of making pairs of gloves to illustrate how the reactant present in the smaller amount (the limiting reactant) determines the maximum amount of product formed. The episode then demonstrates how to identify the limiting reactant and calculate the theoretical yield of product using stoichiometry, worki...

Hess's Law describes how the total enthalpy change of a reaction is the sum of the enthalpy changes of its individual steps. Because enthalpy is a state function, the overall enthalpy change remains constant regardless of the reaction pathway. For more: https://www.chemdunn.com/hess-law

This episode introduces thermochemistry, exploring energy's various forms and transformations. It defines energy, heat, and temperature, differentiating between potential and kinetic energy and explaining their roles in chemical and physical changes. It discusses heat transfer and its relationship to thermal energy, describing exothermic and endothermic processes. Finally, it emphasizes the law of...

This episode explains the systematic naming conventions for inorganic binary compounds, which are compounds composed of two elements. It covers ionic compounds , focusing on how to determine the name of a compound based on its chemical formula and vice versa. The episode differentiates between  Type I  binary ionic compounds, which contain a metal that forms only one type of cation, and  Type II  ...

This episode explains the fundamentals of electrochemistry, focusing on electrolytic cells and electroplating. It defines key terms like oxidation, reduction, anode, and cathode, highlighting the difference between galvanic and electrolytic cells. It then delves into electrolysis, explaining how to determine the products of an electrolytic reaction and how to calculate the amount of substance prod...

This episode provides a detailed explanation of electrochemistry, focusing on redox reactions and galvanic cells. It covers fundamental concepts like oxidation and reduction, balancing redox reactions, and cell potential calculations. It also describes electrochemical cells, including their components and how they operate, as well as the relationship between cell potential, free energy, and equili...