4.3 Chem talk

The first section of this Chem Talk started out with a little review with moles and molar mass, serving as a great refresher on the subject. Just like a dozen donuts is twelve donuts, one mole is 6.022 x 10^23. One of the most important thing to know about moles is that one mole of any atom or molecule is equivalent to its molar mass in grams. Within balanced equations, say if you had 3 moles of baking soda, you would have enough to produce 3 moles of carbon dioxide. In addition to moles, molar volume is also mentioned. Basically all the talk is saying is that one mole of gas in room temperature will occupy more space than when it is in proper temperature conditions. Stoichiometry seemed to be a little confusing. The rest of the talk went into more complicated math stuff involving moles. Hopefully, we can do some in class to further my understanding. Overall, a solid Chem Talk. 

5.2 Checking Up/Chem to go

  1. A molecule’s polarity signals a separation of electric charges between atoms that are attracted to one molecule. 
  2. London dispersion forces are the weakest intermolecular forces. It is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.
  3. C5H12, I think will have a greater boiling point. 

 

 

CTG 4.

b

 

Chem talk 5.2

This chem talk started out by talking about particles in solids and how they remain in place due to the fact that they have a strong attraction to each other. This was all a review of past concepts to me, but helped as a reminder. It was made clear that as you go through the states of matter, the distance between particles becomes larger. Soon, non polar molecules were introduced. They are a fairly simple concept since they have small intermolecular forces due to symmetrical charge distributions. Since the electrons in nonpolar molecules are distributed evenly, there are no permanent charges on the molecule making the forces small. Electronegativity has to do with which molecules are attracted to what. For example, two hydrogen atoms are attracted to oxygen because it has a more electronegativity. Substances with strong attractions to eachother are usually solids. 

Chem Talk 7.8 // Work in Class

Recently in class and in the book, we have been discussing lewis structures of atoms and molecules as well as an introduction to molecular geometry. In class, we have looked at several molecules and have tried to remake them using connectable lego-like atoms and bonds. In the chem talk, a review about how valence electrons are used in bonding is present. It also goes into more about the VSEPR theory. This has to do with the distance between the electrons when bonded to a molecule. Since electrons are negative, they repel each other equidistantly. Different shapes of molecules are formed because of the repulsion theory. This all seems like it is easy to understand, especially when we get a chance to make the molecules with 3-D figures.