Khan Academy: Proof: S (Or Entropy) Is a Valid State Variable

Entropy is the focus of this chemistry video. More specifically, Sal drives the point home that entropy is a macro state variable. This means that a change in the universe's entropy must always be positive, because when heat is added to...

Proof that S or entropy is a valid state variable. [15:38]

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...

A video investigation of what it takes to oxidize alcohols. Video gives examples of how to calculate oxidation states by using electronegativity differences. Also learn what is formed as alcohols are oxidized. [12:37]

Find out how Alfred Hershey and Martha Chase showed conclusively that DNA is the genetic material. [8:49]

Sal Khan demonstrates why S-waves, or transverse waves, only travel in solids. [4:14]

Using a reversible system to clarify the definition of entropy in thermodynamics. [15:38]

Learn the difference between the cold and the flu, and how we sometimes can get fooled by viruses. Rishi is a pediatric infectious disease physician and works at Khan Academy. [12:46]

Did you know why heat increases entropy? This covers how entropy relates to biology and how it can do some work! [7:01]

A follow up to an error made in a previous video( Khan Academy: Chemistry: More on Oxidation States) where the oxidation state of oxygen in hydrogen peroxide was shown incorrectly. This video explains the correct oxidation state for...