4.8

Spencer Macchia

May 19 17

Chem

 

4.8 Chem Talk

 

In this Chem talk we first lean about Enthalpy and Entropy and their relation to the system and surroundings. The system is whatever you are working on like a test tube for example and the surroundings is the environment around it. An open system can translate energy between the system and the surroundings. A closed system is shut off from the surroundings. Energy is governed around a very simple rule that it can’t be created or destroyed. Only transferred witch ties back to Enthalpy and Entropy.

            Next we learn about Polymers. Poly means many witch means many monomers. In the lab in 4.8 we do experiments with rubber bands. When a rubber band is cooled it can be streaked more and when the temperature increases it contracts.

 

4.7

Spencer Macchia

May 14 17

Chem

 

4.7 Chem Talk

In this chem talk we learn about thermodynamics and how chemists call a reaction spontaneous. Thermodynamics can answer the question ‘’can a reaction occur spontaneously?’’ and kinetics can answer ‘’how fast can a reaction occur?’’. Next we learn about the reaction between magnesium and water. When these react it creates heat and hydrogen. The energy required to start this reaction is 572kj and the output is 925kj. This is an endothermic and a exothermic reaction. This is called the activation energy 572kj to start the reaction. Lastly the molecule that starts the reaction is called the catalyst.

 

4.6

Spencer Macchia

May 9 17

Chem

 

4.6 Chem Talk

First we learn that for a solution dissolved in water is conductive when it has electrolytes.  Also a solution is conductive when it has charged particles. These charged particles must be there and they have to move around. In our lab we made battery’s and they are made of two half cells one’s the anode and the oxidation takes place and the cathode is where the reduction takes place. There is also a salt bridge where the no3- ions can travel. Electrons travel through the wires and eventually to the copper through the salt bridge and to the LED.

 

4.4

Spencer Macchia

May 1 17

Chem

 

4.4 Chem Talk

 

 

In the beginning we learn some of the properties of metal, they are shiny and conductive witch makes them great for electric circuits. They are also conduct heat witch is great for cooking. Next we learn about the Activity Series of metals and these were found by pairing and seeing how certain metals react with ion solutions then they recorded their observations. Lastly we learn why hydrogen is important among metals. They are important because of their positive nature and their role in strong acids. Also to find if a metal belongs in the actively series.  

 

 

5.2 Questions

Spencer Macchia

April 13 17

Chem

 

5.2 Questions

 

  1. How polar the molecule is if it is more than .4 in electronegativity is is polar and more than 2 is ionic.
  2. They are weaker than ionic or covalent bonds. And when a atom gets a temporary charge it gets a dipole along with the opposite from another atoms. This attractive force. Is called London Dispersion force. They are also the weakest force and all molecules have London Dispersion forces.
  3. C7h16
  4. B

4.3 Chem Talk

Spencer Macchia

April 28 17

Chem

 

4.3 Chem Talk

 

 

In the beginning of this chem talk we first are introduced to moles again. One mole is equals to . Moles are used for counting molecules like the term dozen. For example, the mass of 16 grams of oxygen if equal to one mole. This is called the Molar mass. To find the Molecular mass of water you have to app up one H and 2 O’s. Next we learn about the Molar Volume of gas. One mole of almost all gasses is 22.4L this is called standard pressure. Finding the moles in the chemical equation is called Stoichiometry. When using Stoichiometry you get to cancel this is called dimensional analysis.

 

Chem reading

 Spencer Macchia

Arial 7 17

Chem

 

Chem Talk

 

Intermolecular force vs Kinetic molecular motion. In this chem talk we learn about the forces within atoms. Within a solid there is a very strong pull form each particle. Intermolecular forces are electrical meaning that they are centered around the positions of electrons.  

            The kinetic motion and force pertain to the status of liquid to gas. It is how much the particles move and when they heat up they move more and when they cool down the proses is reversed.

            In class we have been talking about electron geometry and how to find the different kinds. Also we have talked about partial charged and polarity of atoms. This all goes back to the electron geometry and how the electrons change the shape of the molecules

 

7.8

Spencer Macchia

April 6 17

Chem

 

7.8 reading

In this Chem talk we first learn about the Lewis Structure and we hear again about the octet rule. It is very important to Lewis Structures because a Lewis structure only shows the outermost electrons. Then we learn about VSEPR (Valence electron shell repulsion theory) This is how you can predict what the angles of your molecule are going to look like. In class we started talking about building molecule made up of atoms and Lewis dot structures. Then we built different molecules using models. There were spheres to represent different atoms and different lines to represent different bonds.  

3.6 reading

Spencer Macchia

March 30 17

Chem

 

3.6 Chem Talk

 

In this Chem talk we lean Precipitates and Pigments and different reactions. On our 3.6 lab we observed solids that are insoluble compounds. And they can be used as pigments and then possibly to paints. The proses to make paint starts with a pounder and they it is mixed with a liquid this is called the binder. Next we learned about Double- Replacement Reactions When the cations and anions join each other (then water insoluble ionic compounds can form. When the ions are apart in separate aqueous solutions they are brought together as an insoluble solid.

3.5 reading

Spencer Macchia

February 19 17

Chem

 

3.5 reading

 

In this chem talk we first learned about Hydrates and Anhydrates. A Hydrate is a substance that contains water as a part of its crystalline structure. An Anhydrate is the substance left over from the heated hydrate. Next we learn about a method that chemists developed to count atoms. These are called moles and they = This mole happens to equal exactly 12g of carbon 12. The number is also called Avogadro’s number.