00:01
So here we're asked essentially to determine the change in a certain state quantity, state function quantity.
00:05
So in this case, we have the change in entropy for certain chemical reactions.
00:11
So our first process is basically having the dissolution of nacl in water.
00:16
So as we know, essentially when we dissolve nacl in water, since nacl is a soluble salt, it dissociates into its constituent ions.
00:30
And when you essentially think about essentially a solid versus an aqueous solution, essentially, there's much less constrainment of motion in an aqueous solution.
00:44
So there's basically higher energy in different energy levels, and it's harder to essentially to predict the location of certain ions in an aqueous solution.
00:52
While in solids, it's very easy to pinpoint location, and there's very limited motion.
00:58
So essentially that here we have a higher entropy for the constituent ions compared to the entropy of an aco.
01:07
And let's remember that essentially this is defined as the entropy of the products minus the entropy of the reactants.
01:14
So in this case, since essentially you have a higher entropy for the products, compared to the reactants, delta s is greater than zero, which is since this would be one of the answer choices, since there's an increase in entropy.
01:34
So for the second, basically for the second process, we're basically bringing the temperature of the system down.
01:41
So that less nacl can dissolve.
01:44
So basically our reverse reaction is having some, basically, solution.
01:49
So we're having basically precipitation of nacl to the solid form.
01:56
So essentially, this is the reverse reaction.
01:58
So of our first reaction, so in this case, the products essentially have an entropy that is less than the reactions, according to the reasons that i addressed before.
02:08
So essentially, delta s would be less than zero.
02:10
So in part c, essentially, we're having the freezing of water...