prof Dave here, let’s learn the lawsof thermodynamics the laws of thermodynamics help us understand whyenergy flows in certain guidances and in certain ways. a lot of the conceptsdescribed by thermodynamics seem like common sense but there is a layer ofmath beneath the intuitive degree that draws them very powerful at describingsystems and constructing prophecies. we won’t get into the math but we should be ableto describe these laws conceptually. the first constitution described in the most basicway highlights conservation of energy energy is not created or destroyed itonly alters shapes, from potential vitality to kinetic energy to heat energy, etc.while we have found this to be untrue on the quantum rank, for chemists it doesjust fine.However there seems to be a opted guidance in which energyflows from one constitute to another. in order to understand why we look at the 2nd law.the 2nd statute pioneers a new notion: entropy. entropy is quite difficult tounderstand but we can most easily describe entropy as ailment, and the2nd ordinance states that the sum of the entropies of a structure and itssurroundings must ever increase. in other words the entropy or the disorderof the universe is always increasing within a system there is also a tendencyto go towards higher entropy.The classic analogy is that your bedroom will overtime become chaotic but it won’t abruptly become elegant. another way to look at thisis to say that entropy is a measure of how scattered the energy of the systemis amongst the ways that organization can contain force. yet another way is toanalogize entropic states to computer code. let’s take for example an ionicsolid compared to the same essence as a liquid. clearly the solid state is moreordered and the liquid state is more malady, or higher in entropy. todescribe the solid state working computer code you would need to include words that describe the geometry of thelattice, the intermolecular lengths, the precise configuration of every moleculeand many other things. but to describe the liquid state you would need tosimply describe the loudnes of liquid and the shape of the vessel because themotion and configuration of the molecules are random. that’s far lessinformation that needs encoding which is a way of rationalizing why increasingthe entropy of a system is thermodynamically favorable.We can lookat all kinds of treats to highlight entropic affect. heat will flow from ahot coffee cup into the counter or your hand because the heat energy will bemore ailment if more dispersed. this is why heat spontaneously flows from hotto freezing and not the other way round. entropy. the third law is to say that aperfectly crystalline solid at absolute zero has an entropy of zero as this isthe most required government such substances can be in. entropy is measured in joules perkelvin. note that entropy is not a measure of energy itself but of howenergy is distributed within a structure. it is enthalpy, the thermodynamic quantitywe learned about before that is more accurately describing the exertion of asystem. as we will see enthalpy and entropy intricately relateto tell us something about the Gibbs free energy of a organisation. G, or Gibbs freeenergy tells us whether a process are likely to be spontaneous or not meaning if it is as simple as happen on itsown altered in Gibbs free energy is given bythis equation which includes altered in enthalpy, change in entropy andtemperature. if delta G is negative the process is spontaneous, if positive it isnonspontaneous.So we can use this equation to see how a spontaneousprocess can be either enthalpically or entropically positive or both but notneither. for example if delta H is negative which makes exothermic and energetically positive, and delta Sis positive which signifies an increase in entropy which is also positive, anegative minus a positive will always be negative or spontaneous. if the oppositeis true and both are adverse we have a positive minus a negative which willalways be either positive or nonspontaneous. if only one of the two is positive we haveto do some math. if delta H is positive or endothermic, that energeticunfavorability “couldve been” outweighed by the other term if the process is entropically positive, and since T is here this factor will increase with a largerT so entropically favorable treats are more likely to be spontaneousat higher temperatures.Conversely if it is forcefully positive but entropically adverse the entropic unfavorability will be downplayed atlower temperatures. this is a very important equation to understand becauseit describes all of the spontaneous handles in the universe there are those who incorrectly useentropy and the second law of thermodynamics to imply that order can’t happen spontaneously, but we justshowed that entropically adverse processes can be spontaneous atlower temperatures if they are powerfully favorable. an example ofthis is soap.You need soap to moisten nonpolar dirt and grime off your handsbecause they are immiscible with polar ocean molecules, but soap molecules havepolar abilities and long nonpolar posteriors which allows them to spontaneouslyform organizes called micelles. such is realms where the soap moleculesorient themselves with the polar brains facing out in order to maximize ion-dipole interactions with irrigate molecules that imparting information systems to a lower energyand the nonpolar posteriors will all face in trapping the grime by making a network ofvan der Waals interactions.The grime captured in the micelles rinses awaybecause the micelle as a whole is water-soluble, due to the polar headsfacing out. that’s how soap succeeds and that’s also how most orderedstructures can assemble spontaneously if by enthalpically positive or energystoring operations. in this way organizations can defy entropy on the smallscale but the 2nd principle does hold true in that the entropy of the universe isalways increasing. let’s check apprehension thanks for watching guys, subscribe to mychannel for more tutorials and as ever feel free to email me
