Weekend Homework

Weekend Homework pg.354 1-9 

By Kelly Moran

1.) Petroleum is often considered "buried sunshine" because the energy released by burning petroleum represents energy originally captured from the sunlight by prehistoric plants during photosynthesis therefore petroleum is like "buried sunshine."

2.) a.) Potential energy= A truck filled with explosives

     b.) Kinetic energy= A wheel turning

3.) During a chemical reaction, bonds break and reactant atoms reorganize to form new bonds therefore creating a new substance (for example when fuel is burned).

4.) A molecule of Butane has more potential energy because there are more carbon atoms which create more bonds to break. 

5.) a.) Potential energy

     b.) Potential energy

     c.) Kinetic energy

     d.) Potential energy 

     e.) Kinetic energy

6.) The Law of Conservation of Energy states that energy is neither created nor destroyed in any mechanical, physical, or chemical process.

7.) Energy is required to break chemical bonds because the formation of chemical bonds is an exothermic change which is a product of an endothermic change (energy in endothermic) which is the pulling apart of bonds therefore energy is indeed required for the breaking down of chemical bonds.

8.) a.) Exothermic change  

     b.) Endothermic change 

     c.) Exothermic change

9.) Burning a candle is an exothermic reaction because new substances are created (chemical change) when burning a candle therefore the formation of new chemical bonds are created which makes it an exothermic reaction. Lots of energy is stored into the reactants to make new chemical bonds in the product side of the reaction therefore not a lot of energy is left in the product side. 

Lobsters Immortality

Lobsters Immortality

By Kelly Moran

One thing that you may not know is that Lobsters are immortal. They never die. We have never recorded a death from a lobster of natural causes. They have a very large telomerase activity (telomerase activity allows cells to divide virtually forever which is why they can form tumors) which is the enzyme responsible for ensuring the end of our chromosomes do not become depleted (diminish in number of quantity) with each round of DNA synthesis due to the semi-dicontinuous nature of DNA replication. Basically with lobsters their chromosomes never diminish in quantity because they have natural DNA replication. Lobsters will continue to become bigger and bigger and grow the longer they are alive. This is because like a cancerous tumor which also has a high telomerase level, lobsters go through many cell cycles and must evade the Hayflick limit (the number of times a normal human's cells are divided until cell division stops). Lobsters are killed simply for food from humans or other fish in the ocean but if we didn't hunt down lobsters they would live forever. Because of this discovery lobsters have become popular discussion and research among scientists studying possible immortality for humans in the future. Many people think that the longer telomeres will give them a longer life but it is not that easy. Humans stop growing and usually when we have our cells dividing non-stop they are producing cancerous (bad) cells and are not just simply duplicating our good cells or renewing our DNA like lobsters. Lobsters are very special animals. Now whenever you're eating lobster just remember that it could grow larger than you.

Bibliography: https://answers.yahoo.com/question/index?qid=20120605144629AAfZLvD

http://en.wikipedia.org/wiki/Lobster

http://en.wikipedia.org/wiki/Telomerase

Thursday Homework

Thursday Homework pg. 324 1, 3, 4, 5, and 21

By Kelly Moran

1.) A covalent bond is a when two or more valence electrons are shared between two atoms.

3.) This analogy describes the way that shared electrons hold together atoms in a covalent bond because the dogs represent the atoms and the sock represents an electron and they are sharing it by both tugging on it. 

4.) Each dot in a Lewis dot structure represents a single valence electron.

5.) The advantage of using a dash (structural formula) instead of using electron dots to represent a covalent bond is that the dash is easier to write. Dashes also clearly show which atoms are sharing which electrons. 

21.) 

Wednesday Night Reading Concepts

Wednesday Night Reading Concepts 

By Kelly Moran

 In chapter B sections 1-4 I learned many new concepts. Polymers are a category of designed molecules. A polymer refers to a large molecule typically composed of 500 to 20,000 or more repeating units of simpler molecules. These simpler molecules are known as monomers. Organic chemistry is the study of hydrocarbons and their derivatives, including the polymers we learned in section B.1. Carbon atoms are joined to form a backbone called a carbon chain. Similar energy levels in elements are grouped together into shells. Valence electrons are electrons that are associated with an atom and can participate in a formation of a chemical bond. The sharing of two or more valence electrons between two atoms is called a covalent bond. The chemical bond formed between two atoms that share a pair of electrons is called a single covalent bond. Lewis dot structures are a formula in a hydrogen molecule and are represented by dots surrounding each element's symbol which in the representation represent the valence electrons for that atom. Petrochemicals are a category of chemicals that include detergents, pesticides, pharmaceuticals, and cosmetics. Compounds produced from oil or natural gas are petrochemicals. The two carbon atoms in an ethane molecule share two pairs of electrons. This produces an arrangement of electrons called a double covalent bond. These are all the main concepts from the reading last night!

Wednesday Homework

Wednesday Homework 

By Kelly Moran

#24-26 pg. 294

24.) Octane (CH8H18) has the highest boiling point, Hexane has the 2nd highest, Pentane has the 3rd highest, and Methane has the lowest boiling point. The amount of carbon atoms determines the boiling point. If there are more carbon atoms the boiling point will be higher and if there are less it will have a lower boiling point. 

25.) a.) 

        

       b.) 

       

26.) a.) A long straight chain would have a lower boiling point because the more bonds the more weaker it is therefore the boiling point lowers.

       b.) A long branched chain would have the lower boiling point because the branched chains always have the lower boiling points. 

      c.) A short branched chain would have the lower boiling point because branched chains have lower boiling points than straight chains. 

1-6 pg. 282

1.) a.) The data (hydrocarbons) in table 3.3 are organized in alphabetical order. 

     b.) It's useful in that if its organized in alphabetical order the hydrocarbons are easier to find but it's non-useful in that it's harder to find the lowest boiling point and the highest boiling point and it doesn't show the relationship between the carbon atoms and the boiling point. 

2.) a.) A way that's easiest to organize this data is going from lowest boiling point to highest boiling point. 

    b.) 

    

3.) Butane, Ethane, Methane, Propane 

4.) You can infer that the boiling point is less than 22 degrees celsius. 

5.) Pentane.

6.) You can infer the intermolecular forces among butane molecules are much weaker than those of among decane molecules because the hydrocarbons that are lower in boiling point will always have weaker intermolecular forces and the ones that have a higher boiling points will always be stronger.  

6-8 pg. 286

6.) 

7.) a.) 

            i.) Heptane

            ii.) Nonane 

       b.) Heptane= C7H16

            Nonane= C9H20 

8.) a.) C25H52

     b.) I decided to write the molecular formula because it's easier and takes shorter amount of time to comprehend. 

20-22 pg. 295

20.) They are not isomers of each other because all of the depictions are the same. In order for it to be an isomer all the depictions (straight branch vs branched) must be different but still represent the same molecule. 

21.) 

22.) Ethane

  

Tuesday Night Reading Concepts

Tuesday Night Reading Concepts

By Kelly Moran

In last nights reading, I learned some new concepts and terms. I learned about an extrapolation which is a procedure in which you follow the trend of your best-fit line by extending a dashed line from the best-fit line you drew for the first 10 alkanes. Polar molecules are molecules that exhibit permanent partial charges. Opposite partial charges in neighboring polar molecules attract one another, resulting in intermolecular forces (attraction or repulsing with neighboring particles) between the molecules. A straight-chain alkane is a representation where each carbon atom is only linked to one or two other carbon atoms. Branched-chain alkanes are where one carbon atom can be linked to three or four other carbon atoms. An alkane composed of four or more carbon atoms can either be represented as a straight-chain or a branched-chain. Structural isomers are different representations and models of the same molecule. These are all the main concepts and terms that I learned from last nights reading!

Tuesday Homework Questions

Questions 17-23 on pg. 295

17.) a.) C9H20

       b.) C10H22

       c.) C16H34

       d.) C18H38

18.) a.) 128.106 grams/mole 

       b.) 142.276 grams/mole 

       c.) 226 grams/mole

       d.) 254 grams/mole

19.) a.) (Propane) C3H8= 44 grams/mole 

       b.) (Pentane) C5H12= 72 grams/mole

20.) No because all of the depictions are the same chain in this depiction rather than being different. 

21.) 

22.) Ethane

23.) Whether an unbranched hydrocarbon molecule is represented by a linear chain or as a zigzag chain doesn't matter and both are correct ways of depicting an unbranched hydrocarbon molecule because both depictions show the same amount of carbon atoms and hydrogen atoms.