Energy is like the bestest best friend ever and yet, most of the time we take it for granted. Hank feels bad for our friend and wants us to learn more about it so that we can understand what it’s trying to tell us - like that any bond between two atoms contains energy. How much energy? That’s not the simplest question to answer, but today Hank will answer it (kinda), by teaching us about a nifty little thing called enthalpy.
If you are paying attention to this episode you’ll learn what the state function is, and how it varies from a path-dependent function; why enthalpy change is different from heat; that bonds are energy and to form and break them they release and absorb heat to and from their environment. You’ll get the quickest introduction to calorimetry ever (more on that in upcoming episodes) and learn the power of Hess’s Law and how to use Germain Hess’s concept of the standard enthalpy of formation to calculate exactly how much heat is produced by any chemical reaction.
Grumpy Professor Hank admits to being wrong about how everything is chemicals. But he now wants you to listen as he blows your mind with a new sweeping statement: everything (yes, really everything this time) is energy. What?! This week, Hank takes us on a quick tour of how thermodynamics is applied in chemistry using his toy trebuchet as an example, because he is a proud nerd.
Ah, shmurg, it’s time for the mystery document? The rules here are simple. I read the mystery document and I’m either shocked by electricity or by the fact that I got it right.
John Green, Crash Course US History #17 (via bruceandmary)
In which John Green teaches you about the Mexican-American War in the late 1840s, and the expansion of the United States into the western end of North America. In this episode of Crash Course, US territory finally reaches from the Atlantic coast to the Pacific Ocean. After Oregon was secured from the UK and the southwest was ceded by Mexico, that is. Famous Americans abound in this episode, including James K Polk (Young Hickory, Napoleon of the Stump), Martin Van Buren, Zachary Taylor, and Winfield Scott. You’ll also learn about the California Gold Rush of 1848, and California’s admission as a state, which necessitated the Compromise of 1850. Once more slavery is a crucial issue. Something is going to have to be done about slavery, I think. Maybe it will come to a head next week.