Voltaic Cell Animation

Hey guys! So I found an animation on YouTube that demonstrates what happens in a voltaic cell. If any of you have struggled with understanding this, watching this may help!!
https://www.youtube.com/watch?v=J1ljxodF9_g

Spontaneous Reactions

It was really interesting to see today Kayli's demonstration of what a spontaneous reaction can look like. You know, I can't help but think about how a large majority of reactions we have done in lab are spontaneous reactions. It seems as if a lot of reactions in nature are actually spontaneous, and yet there are still quite a few times in which we have to continually input energy in order to maintain the reaction. It certainly is easy to tell the difference between the two though, since if a reaction starts and keeps going without us doing anything it must be spontaneous. 

But why do you think that might happen? According to the Second Law of Thermodynamics, it seems as if the universe will actually move towards disorder on its own. What do you think this might mean in terms of reactions? What would be classified as "orderly" and "disorderly"?

Just some fruit for thought, see you all either tomorrow in lab or in class on Wednesday.

Matt

Doubt

Verb: feel uncertain about, question the truth or fact of (something), disbelieve (a person or their word), feel uncertain, esp. about one's religious beliefs.

As the definition implies, the word “doubt” carries a substantial negative connotation, especially in reference to religious beliefs.  From a Christian perspective doubt is seen as especially dangerous territory.  One of the twelve disciples has even been labeled as “Doubting Thomas” due to his disbelief in Jesus’ rising from the dead.  Doubt brings questions about a topic or theory to the surface; when the item in question is something as central and important as one’s faith, there is resistance to those questions because there is fear that it could shake one’s faith.  However, in her talk on 3/20, Dr. Francl presented doubt in a far more positive setting.  She proposed doubt as an opportunity to ask questions that enable one to dig deeper and learn more about a topic.  With this approach, we need not see doubt as something that is going to completely change our minds or force us to turn our backs on our faith.  Instead, doubt can be seen as an invitation to investigate a question in order to learn more about an aspect of Christian faith.

Chapter 19 Practice Sheet

Answers: 1. Each of the metals in the complex ions give have CN=4 and a charge of +2. Each is a square planar geometry. 2. d10/zero, d3/3, d8/2, d7/3 unpaired d electrons

LEWIS acids and bases--no conjugates here!

Gilbert N. Lewis is famous for many things, among them is his definition of acid/base chemistry. A Lewis acid is electron deficient. Generally, transition metal cations are considered good Lewis acids. A Lewis base is electron-rich and after collision, can stick to a Lewis acid through sharing an unbonded pair of electrons. When talking about transition metal chemistry, Lewis bases are the ligands that coordinate (bond or stick) with the metal cation. Electron-pair suppliers can come from molecules that contain an atom with a nonbonded lone pair -- such as N in NH3, N in en, O in H2O. Electron-pair suppliers can also come from anions in solution -- such as O in ox, Cl-, N in CN-. Chelating ligands are long and flexible enough to be polydentate. Both en and ox are both important examples of bidentate ligands. They act as Lewis bases and coordinate to a metal in two positions. When Lewis acid/base chemistry happens between a transition metal cation and ligands in aqueous solution, the result is a complex ion, often with a beautiful color. The formation of complex ions is reversible and so a K value (Kf) can describe the equilibrium composition of the mixture of Lewis acid, Lewis base, and the complex ion.

The Intersection of Science and Religion

Hi everyone!

If you made it through the snow to see Dr. Francl's presentation on how she connects her faith to her work in chemistry, you heard quite a great talk! If you missed it, it is definitely something to look into if you are interested!

I thought it was really interesting that Dr. Francl clarified that it's not just that science and religion mesh at any singular points, and it's not that only certain parts of science and religion work together - but rather, that science and religion are completely related. God has created everything, and we as Christians can really look at the world as God's word. By learning and understanding the world, we can learn about God's greatness and can really learn how to fit our faith into our love of science!

Kayli

Weak Bases in Search of H+

Bases move around looking for a partially positive H to snag as H+. H+ is welcome to take the spot at a lone pair site inherent to a weak base (like on N as part of an amine) or a vacant spot by attraction to a negative charge (on anions). If a base collides with the H part of an acid, the base's ability to steal the H+ away is assessed by the value of Kb. A large Kb means the base is a serious thief, a collector of H+. The smaller the Kb (and larger the pKb) means the acid doesn't have to worry too much about acting as an acid. The Kb of the anions of strong bases are so low, that those anions are essentially ineffective as bases (weaker than weak). They are referred to as spectator ions. Can you list the anions of the strong bases you have memorized?