Khan Academy
Khan Academy: Chemistry: Hess's Law and Reaction Enthalpy Change
A video lecture giving an explanation of Hess's law, the law of heat summation. Understand that whether the process takes places in one or several steps the heat released or absorbed in a chemical process is the same. The video also...
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Khan Academy: Chemistry: More on Entropy
A video lecture describing how entropy is a macrostate variable that also describes the number of states a system can take on. The video explains some misconceptions about previous given analogies to describe entropy. [9:30]
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Khan Academy: Chemistry: Stoichiometry of a Reaction in Solution
A video lecture investigating how to solve problems using stoichiometry. The lecture shows viewers step-by-step how to solve for the mass needed of a substance in order for it to completely react with a solution. [10:18]
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Khan Academy: Chemistry: Stoichiometry Example Problem 2
A video lecture showing step-by-step how to solve a stoichiometry problem. The problem gives you a given number of grams of a molecule, and ask you to solve for how much of another molecule would be to required to completely react with...
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Khan Academy: Chemistry: Enthalpy
A video lecture explaining enthalpy is the heat applied to a system if the pressure is constant in the system. Also explored is internal energy and when the pressure of a system would be constant. [15:07]
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Khan Academy: Chemistry: Exponential Decay Formula Proof
A video lecture showing how a general function of time can give you the amount of the decaying substance. The video derives the function and explains the logic along the way. Some calculus is involved. [12:22]
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Khan Academy: Chemistry: More Exponential Decay Examples
Do you need some more practice on half life problems? This video lecture will give you more examples of how to solve exponential decay problems. The video is easy to follow with step-by-step explanation of how to find the half life or...
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Khan Academy: Chemistry: Work Done by Isothermic Process
A video lecture explaining how to find the work done in an isothermic process. Lecture defines how the adiabatic process is isolated from world and an isothermic process keeps the temperature the same. Video looks at temperature, ideal...
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Khan Academy: Chemistry: Volume Ratios in a Carnot Cycle
A video lecture to show that the ratios between the volumes at different points in the Carnot cycle are the same. The lecture contains a lot of math to prove a simple point. While going through the math, the adiabatic processes and...
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Khan Academy: Chemistry: Stoichiometry Example Problem 1
Learn how to figure out the number of grams of reactants and products produced from a reaction. This video lecture explains a step-by-step procedure for solving stoichiometry problems. [13:35]
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Khan Academy: Chemistry: Quasi Static and Reversible Processes
Understand that an almost static process is called quasi-static process in this video lecture. Also explained is how all reversible processes are quasi-static but not all quasi-static processes are reversible. Video lecture gives...
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Khan Academy: Chemistry: Carnot Efficiency 3
A video lecture proving the Carnot engine is the most efficient engine. The video starts by explaining the basics of heat engines and the Carnot engine. Then the video compares the efficiency of the Carnot engine and a proposed super...
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Khan Academy: Chemistry: Efficiency of a Carnot Engine
A video lecture defining efficiency for a heat engine and the efficiency of a Carnot engine. Using the area under the PV diagram, the lecture explains how the efficiency of an engine could be calculated. [14:04]
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Khan Academy: Chemistry: Pv Diagrams and Expansion Work
Learn that the area under a curve can help you find the work done! This video lecture explains why a pressure vs. volume graph could be used to find the work either on or by the system. The video does not go through the calculus of how...
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Khan Academy: Chemistry: Work From Expansion
A video lecture showing how heat is transferred between systems, how to calculate work, and how if the system is doing work the volume increases. Lecture uses diagrams and examples to help illustrate concepts. [12:43]
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Khan Academy: Chemistry: Carnot Efficiency 2: Reversing the Cycle
Learn how the Carnot engine is the most efficient engine in this video lecture. The lecture begins with describing a heat engine and the steps of Carnot cycle. The video also explores how the engine would need to be frictionless and...
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Khan Academy: Chemistry: Vapor Pressure Example
Learn how to solve for the number of water molecules needed to evaporate to give a particular vapor pressure in this video lecture. The problem uses the ideal gas law to solve for the number of molecules of water. The problem is solved...
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Khan Academy: Chemistry: Proof: U=(3/2)pv or U=(3/2)n Rt
A video lecture that relates pressure, volume, and temperature to internal energy. The lecture shows how to derive an equation for the ideal gas to relate internal energy and pressure and volume. The video shows that if the temperautre...
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Khan Academy: Chemistry: Proof Entropy Is a Valid State Variable
A video lecture defining a state variable and the characteristics of the value. Understand that to be a valid state variable its value should remained unchanged as it goes around the Carnot cycle. Video shows the math and theory behind...
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Khan Academy: Chemistry: Gibb's Free Energy and Spontaneity
Understand the intuition to why Gibb's free energy equation can predict whether a reaction is spontaneous in this video lecture. The lecture goes through scenarios to show how a reaction may happen spontaneously based on enthalpy,...
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Khan Academy: Chemistry: Spectrophotometry Example
Using Beer-Lambert law, the video lecturer solves for an unknown concentration based on the absorbance. Also solved for is the constant in the formula for Beer-Lambert law. [12:42]
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Khan Academy: Chemistry: Thermodynamics and Entropy
A video lecture discussing the definition of entropy as the change of states and as the heat added to the system divided by the temperature added. The video reconciles these two definitions by going through examples to explain how they...
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Khan Academy: Chemistry: Acid Base Titration
A video lecture using the concept of titration to find the mass of a compound. The video gives a step-by-step process to solve a problem found in a general chemistry textbook. Given is the mass of the acid dissolved in water and the...
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Khan Academy: Chemistry: Limiting Reactant Example Problem 1
A video lecture explaining how to solve a limiting reactant problem. The problem is solved in an easy to follow step-by-step process where each step is explained. Also learn how to distinguish between the limiting and excess reactant....