# 4.3 Stoichiometry

Stoichiometry can be defined as the study of relationships among substances involved in chemical reactions. Basically a complicated way of unit conversion, with elements. In this section we learned how to convert elements or compounds from moles to grams or liters or visa versa. 1 mol of any element is equal to the mass (in grams) of that same element. Once you get into chemical equations, which typically include more than one substance, you also have to consider the coefficients. If an element that you are converting has the number 3 in front of it , when calculating the amount of grams of one of the substances that you are using, you would put the amount of grams x3 over three moles.

# 4.6 Checking Up Questions

1. Because NaCl contains a metal, C12H22O11 only contains nonmetals. Only metals can have ions. Non metals do not have ions.
2. Electrolytes  are a solute that can form ions in an aqueous solution non-electrolytes cannot.
3. The zinc will be a pure metal and the cooper will be an ion, in a battery. because zinc is higher on the activity series.
4. The zinc is the anode, because it starts off as a pure metal then turns into an ion, gaining electrons.
5.  The cooper is the cathode because it starts off as an ion then turns into a pure metal, losing electrons,

# 4.6 Electrochemical Cells and Half Reactions

Over the past two classes, we have been working on a lab focusing in the activity series: what it is, what is it used for, and how to write correct equations from it. (Oxidation, Reduction, and Redox). In this chem talk, it goes into more specific ideas of the activity series and that is electricity. The example used is very relevant and sacred to almost all humans on the planet: Batteries. (the technologically addicted ones).  Batteries are an example of an electrolyte because the current only flows in one direction. Like the equations, there can be written in two different ways, however, only one of them can occur in nature. Electrolytes are a solute that forms ions in an aqueous solution. I have to confess, that the only type of electrolyte I have ever heard about before this chem talk is when athletes are encouraged to drink sports drinks during a break so they can replenish their electrolytes.

# Chapter 4 Section 4

In this section we went further into the properties of metals, their reactions and their ions.  I have learned how to distinguish the difference between metals and nonmetals due to their distinct nature. Metals are shiny, mailable and conductive. A new distinct property, oxidation, made its appearance in this chapter. Oxidation is defined as giving up electrons. The opposite of Oxidation is called Reduction, is receiving electrons. In class we discussed the real life situations of high active metals and nonmetals. For example gold and silver have a low activity. Zinc has a high activity due to how delicate of a metal it is.

# 7.8 Modeling Organic Molecules

This section primarily focuses on bonds on a geometric level. The main principle of bonds is that all of the atoms follow the octet rule (with the exception of hydrogen that wants two electrons). Atoms, depending on the amount of valence electrons either want to gain, keep or lose all of their valence electrons. Elements with three or fewer electrons desire to lose their valence electrons. Elements with five to seven valence electrons want to gain more electrons. Elements with four valence electrons, for example carbon, want to keep their electrons and only partake in covalent bonds.

# 4.2 Balancing Equations

Even though life at Suffield Academy can get a little hectic sometimes, from classes to sports to having a healthy social life. Sometimes you need to learn how to balance your time and energy. Sure, most people would rather be having out with friends rather than writing a paper but as a student you need to figure out and adjust what works best for you.It might be a little hard to believe but this also applies to chemistry, chemical equations need to be balanced.  A balance equation means that they are the same number of elements that are reactants as products. This is proven by the laws of conservation of matter: Matter cannot be destroyed or created. This is applicable to making anything. For example say yo are  baking  chocolate chip cookies first you measure out the specific ingredients (elements)  then mix them together (compounds)  then bake them off (heat energy) and the cookies end up being the product. During the process their is the same exact amount of all of the ingredients just arranged in a different way. Nothing is lost and nothing is gained (unless you eat all of the cookies).

# 5.2 Chem to Go

1. Because gases have full valence shells, so that means that they do not want to lose or gain any electrons. Therefore- little to no bonding.
2.  a) non polar b) polar c) non polar
3. b highest then c=a
1. B is the only one liquid at room tempature
4. B) the intermolecular forces in water are much stronger than those of the methane gas.

# 5.2 Intermolecular Forces in Solids, Liquids, and Gases

In this chem talk, I learned about the intermolecular forces between molecules. Intermolecular forces have electrical charges: positive or negative. I never realized that the states of matter have different kinds of intermolecular forces. For example, the molecules of a solid substance only vibrate, they do not move around. This is the reason why solids have a definite shape and volume, having both of those properties are only limited to solids. Then this section also brings in new terms and concepts, such as, electronegativity and polarity. Electronegativity is the ability of an atom of an element to attract electrons in a chemical bond. Polarity is the difference of electronegativity of neighboring atoms which causes the electrons to be more attracted to one of the atoms in the bond making one of the atoms slightly negative and the other slightly positive. Any atom that is symmetrical has no polarity due to all of the bonds cancelling each other out.

# 3.6 Blog Post

As a novice painter and art student, I was truly  fascinated about learning the science behind pigmentation. Pigments are critical for making paint, ink and other colorful materials that artists use to create their masterpieces. Pigmentation exists because of precipitates. In the lab that we started in class this morning, our group was responsible for identifying what two solutions, when combined, formed solids within the mixture. When a solution has solid particles imbedded in liquid, it is called a precipitate. Scientist can prove that paint is a type of precipitate. When paint dries, and the liquid base evaporates, there are still remnants of the pigment left behind. The color of the pigmentation depends on the compounds. The chem talk also went further into the different parts of Double Replacement Reaction, a reaction in which two ions in two different compounds exchange places to form new compounds. In every double compound there is also a possibility of having spectator ions, which are ions do not participate chemical reaction.  Then finally the talk refreshes the class on the terms of soluble and insoluble.

# Section 2.8 blog post

As I sit here at my desk,  I look around and see different kinds of bonds: from the water bottle on my desk to the makeup and hair products. In this unit we are learning about the different ways that atoms can bond together. Lets start form the beginning, for an atom to be stable it must have a full valence shell, which for the 1st shell that is two atoms for all of the following sub levels it is eight electrons.  All atoms besides the noble gases are unstable and want to be stable. To achieve this, atoms must bond together. During bonds, atoms either have to lose or gain electrons. Ionic bonds are when one atom just gives all of its valence electrons to another electron. On example of this is Zinc Oxide, an  ingredient found in one of my foundations (hopefully not a bad thing) . Zinc has two valence electrons and oxygen has six valence electrons: So the Zinc atom gives its two valence electrons to the oxygen atoms making both atoms have a full valence shells. The zinc atom has a positive charge and the oxygen atom has a negative charge. The other type of   bond discussed was covalent bonds. A covalent bond is when atoms share electrons. The most common example of this, also given in the textbook, is when two hydrogen atoms combine with one oxygen atom. Since an oxygen atom has six valence electrons, it requires two more to make a full shell; and since hydrogen atoms only have one electron, two hydrogen atoms are required to make the valence electron full. Without bonds the world around us would be just a mess of atoms: free floating and exploding.