You can catch flies with honey, but you can catch more honeys being fly

4.7 Checking Up Questions

  1. For a change to occur spontaneously, a chemical reaction continues to occur on its own once it begins.
  2. “Will it continue to occur” and “How fast will it occur” determine if a change can occur spontaneously.
  3. To tell if it is exothermic or endothermic, you have to look at the locations of the reactant energy and project energy which indicates whether the overall enthalpy change is either one.
  4. Energy in an exothermic reaction comes from if the starting point is higher than the ending point and then the system releases heat energy to the surroundings.
  5. Two things that chemists use to speed up a reaction in a MRE heater is something with more surface area and something that can act as a catalyst, like iron.
  6. A catalyst provides a lower-energy alternative pathway for the reaction to take so they have enough energy to get over the energy barrier.
  7. When there is a catalyst the barrier is smaller so it is easier to get over but when there isn’t a catalyst the barrier is bigger and the bump is harder to get over. However in the end the products go down and end in the same place.

4.7 Chem Talk

The following Chem Talk is called Thermodynamics. I learned that some reactions can continue to occur on its own once it begins and that this reaction is called spontaneous. This made total sense because of the meaning of the word when it is not related to chemistry. Thermodynamics and Kinetics are both theories that predict when it will occur spontaneously and how is can speed up and slow down. When a energy change; however, occurs at a constant pressure, chemists call this “change in enthalpy.” If the change is negative the reaction is exothermic and if the change is positive then the change is endothermic. The bump is the height of the reactant energy. This is called the activation energy and is always positive. The top part, which is the state in-between the reactants and products is called the activated complex. The last interesting thing I learned was about the catalyst, which is a substance that speeds up a chemical reaction without being used up itself. For example, anything with more surface area makes the reaction faster and also iron is one in a reaction between magnesium and water. This was a very information filled chem talk and I was a bit confused, but we will see what happens during the lab when its all cleared up.

4.6 checking up questions 1-5

  1. NaCl conducts electricity because when the crystals dissolve in water the sodium ions and chloride ions separate. Molecular compounds do not break up into ions when they dissolve. This means they cannot move around in water and cannot conduct electricity, which is why C12H22O11 can’t.
  2. An electrolyte is a substance that dissolves in water to make solutions that conduct electricity and non-electrolytes are molecules that do not form ions in a solution.
  3. The Zinc electrons come from the zine metal and then travel through the wire. Then the electrons reach the copper and the copper takes them. 
  4. The anode of a battery is when oxidation takes place and the electrons are released into the circuit. The anode is negative when giving away. .
  5. The cathode of the battery is where reduction takes place and the electrons are received. The cathode is positive when receiving. It is at the end where the electrons are received. 

4.6 Chem Talk

This chem talk was not very long but I managed to learn that some solutions are capable of conducting electricity and some of the particles with it.

Chem to Go questions 3-4 and 7-11

3. a. Al    

b. Fe  

  c. Al

4. The pair Al and Pb

(Al -> Al3+ + 3e-) x2

(Pb2+ + 2e- -> Pb) x3                      

 2Al + 3Pb2+ -> 2Al3+ + 3Pb

7. c.) the same

8. b.) Zn(s) –> Zn2+(aq) + 2e-

9. d.) loses an electron

10. b.) electrons will go from Cr3+ to Al

11. magnesium

4.4 Chem Talk

In this chem talk I learnt a few new things. It taught me about properties of metals and what they are capable of when they are met with outside forces. The chem talk spoke about alchemists. I had heard of the name before but never knew what exactly they did. They discovered some metals react more easily with most metal ion solutions than other metals do. Another new aspect I read about was oxidation- reduction reactions. I had heard the word oxidation before, either throughout my day or earlier in the year. However, what I did know was that it had to do with electrons. They also call these reactions “half reactions.” It is smart that they call these reactions half-reactions because both sides react and based on how many electrons you give away, you will get that many electrons back by the other element. Some metals might not be a metal and a example of this is hydrogen. Hydrogen has no properties of a metal but it takes on the positive nature of a metal in strong acids. An example of this would be hydrochloric, which is HCl vs. NaCl. This chem talk brought back familiar faces, and even helped me learn new things. It was very interesting and I am ready to see what is in store for us in class.

4.2 Chem Talk

Balancing chemical Equations is very interesting and at first was a difficult concept to master. However, with practice in class and while doing homework it became easier. The law of conservation is the amount of matter present before and after a chemical change stays the same. Even though the same amount of each element must enter and exit with the same amount. Recently in class we have been talking about intermolecular forces, to be specific the bonds that make up those forces. Learning about the different kinds of intermolecular forces is very interesting since there are so many kinds of bonds with varying strengths and energy levels. The stronger the intermolecular force the higher the boiling point the weaker it is the lower the boiling point is. The strongest of the bonds is ion-ion with an energy of 800 and London dispersion forces with the lowest energy of 10.

4.3 Chem Talk

The beginning of this section started off as a bit of a review session. It began talking about moles and molar mass, which was a great refresher. 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. The Chem talk spoke about balancing equations and incorporated moles into it. When it comes to balancing equations, I knew what it was talking about, but when they added moles it began to get tricky 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. I still don’t have a full grasp of the material, but this is just the first assignment and we’re yet to see what will happen in class.

Chem to go 5.2 questions

  1. Most gases have a small amount of attraction between, because the molecules are very far apart from each other in a gas. The shape of the nonpolar molecule causes this and gas has a shape with the molecules spread out very much, their is little attraction between each other.
  2. a.polar     b. nonpolar   c. nonpolar
  3. b,c,a       a
  4. The intermolecular forces in water are stronger than those in methane. 

Chem talk chapter 5 section 2

There were also somethings that was introduced for the first time to me. This was called Intermolecular forces vs./and kinetic molecular motion. This was called Intermolecular forces vs./and kinetic molecular motion. The forces was the relation between the number and position of the electrons. The kinetic energy overcame the forces when heat was added and the next state of matter took place. The energy got greater when heat was added. This is just like ice, steam and water. When the ice melts into water and can be boiled and turned into steam. The ice freezes then heat is added and energy overcomes some force, then turns into water and heat is added and energy does its magic, and lastly it is steam. A new term I learned was nonpolar molecules which have shapes and bonds that are symmetrical. Something I found that was fascinating to me was when the size of the nonpolar molecule increased, the attractive forces between the molecules also begin to increase.

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