This chem talk was very long and covered a variety of topics. Something that automatically stood out to me was the discussion of polymers because this is something we learned about in detail earlier this year. This section of the reading talked about how rubber bands are affected by temperature. Another part of the reading that proved to be very beneficial for me was the discussion of spontaneity, which includes enthalpy and entropy changes. We covered these topics in depth in class, however this reading helped me further understand these topics. Enthalpy is when heat energy is reduced, making an endothermic equation. Entropy involves the disorder of the particles. If the particles are extremely disordered, entropy increases. One of the things I found most interesting and convenient was that we were able to test both these topics in the lab constructed in class. In this lab we made multiple reactions and tested the temperature before and after deciding weather each was an endothermic reaction. This lab helped me further my knowledge on the topics discussed in the reading. Overall, this chem talk helped me further my knowledge on many of the things we have spent time in class discussing.
- A spontaneous reaction mean that the reaction will continue to occur on its own after it has started.
- The two questions that determine weather a spontaneous reaction can occur are the following; if the change results in a change of heat energy or if particles in the change become disorderly.
- endothermic means the bond is being broken down and energy is being added, endothermic means the bond is being formed and energy is being released.
- The bonds holding the atoms together produce the energy in an exothermic reaction.
- Magnesium, powdered iron, and salt water.
- A Catalyst provides an alternative pathway for the reaction to take place which speeds up chemical reactions because the paths are lower in energy
- This diagram will start at a higher energy and takes less time to react.
This section chem talked discussed a topic that I was not familiars with which is spontaneous reactions. This chem talk introduced me to many new concepts, and gave me an insight to what we will be talking about in class. One of the things I found to be most interesting in this reading, is that chemist can control the speed of a reaction. In order to do this they use two theories, thermodynamics and kinetics, the first determining if the reaction will occur spontaneously and the second determining how fast/slow it will occur. Another thing I learned is that two ways to determine if a reaction is spontaneous or not is to see if there is a change in temperature, and see how much the particles are spread out. Overall, this chem talk was a great way to introduce me to a whole new topic that we will begin learning more about!
This section Chem Talk helped me further understand the experiment we did in class. One of the things that helped me understand the experiment, is that electrolytes are substances that dissolve in water, which determines weather the water will conduct electricity. If the substances dissolve, the water will conduct electricity. If the substances do not dissolve, they will remain as full particles and will not conduct electricity. We did that in class, using a circuit and two different liquids determining which one would conduct electricity. Another thing I learned in this chem talk is that in order conduct electricity, a solution must have charged particles that are able to move around. I found it interesting that a battery has two half cells, one where oxidations occurs and the other one reduction occurs. The activity series we have talked about can relate to how strong a metal reaction will be. The further apart the metals on the activity series the more reactive will be. In conclusion, this chem talk was very insightful and helped me further understand the experiment we conducted in class.
This section chem talk included many interesting things related to what we did in class today. The beginning of the reading discussed how Alchemists, those who unsucessfully tried to make gold from other metals, discovered that some metals are more reactive than others in their findings. This was very cool to me. Another thing I found interesting is that this chem talk reiterated what we have learned about the property of metals in the past. I found it very helpful to use my prior knowledge to help me expand my current knowledge of metals and their properties. This reading also closely related to the experiment we conducted in class with the circuit. Something new I learned is that reactions between metals and metal ion are called Oxidation, which translates to giving away an electron, and Reduction is receiving electrons. Lastly, the reading discussed how you can tell which equation correctly describes a reaction when given two equations, because one will be more reactive. Overall, this Chem Talk gave me insight into reactive metals and how to create equations for them.
This section chem talk discussed some of the concepts we have been working on in class. One of the things I found easy to understand is that a mole, is a constant that is used for counting large quantities of small things. We learned about moles earlier this year, so this topic was familiar to me. Stoichiometry involves the calculations of moles; for example, the experiment we did in class. This concept is still a little confusing to me, but the experiment with the carbon dioxide filling up the balloon helped me further understand it. This chem talk was very clear, and the defined words on the side helped, but I feel like there is still more to learn. Another thing I find interesting is that the stuff we are learning is starting to relate to each other, which makes things easier to understand. Overall, this chem talk was very insightful.
- Checking Up questions 1, 2, and 3 and Chem to Go question 4
- A molecules polarity has to do with the electronegativity difference between atoms, in other words the difference in charge between two atoms, which will determine how attracted they are to each other.
- The London dispersion force is a very weak intermolecular force.
- C7H16 has a higher boiling point then C5H12
Chem To Go
4. Water is a liquid at room temperature, while methane is a gas. Which of the following statements correctly describes the intermolecular forces between these Molecules?
- The intermolecular forces in water are stronger than those in methane
In this section chem talk I learned some new things, and some of the things discussed were concepts I was familiar with. I was able to thoroughly understand the first couple paragraphs because it was talking about what we learned about molecules in solids liquids and gases. It was interesting to be able ti relate my prior knowledge into what we’ve been learning in class. One new thing I learned is that these intermolecular forces (atoms and molecules attraction to each other) are based on the number and position of electrons. The last paragraphs of this section which discussed intermolecular forces, and polar/non-polar molecules proved to be confusing for me. One thing I found interesting is that non polar molecules tend to be gases or liquids because the electrons are distributed evenly, and non permanently, with small intermolecular forces. On the other hand, polar molecules have permanent charges as a result of the atoms in these molecules. Overall, this chem talk contained lots of new information, and some information that I was already comfortable with.
In this section chem talk and the activities we have been doing in class, I learned more about the Lewis Structures of Atoms and Molecules. The reading helped me learn more about how the bonds work, and the difference between lone bonds and covalent bonds. This concept has been a little easier to comprehend because I am able to use my prior knowledge on bonds and valence electrons to help me with these structures and bonds. One of the things I found interesting is that there are four different strings which represent the carbon atoms in the methane. I found it very helpful and beneficial to actually make the 3D models of the Lewis Structure because it further described the bonds that were being made and how they are different. Overall, what we did in class and this reading expanded my knowledge on this topic, but there is still more to learn!
In this section chem talk, I learned more about color pigments, paints and precipitates, which we began to discuss in class. I learned many new things, as I did not have prior knowledge to this before this section. One of the things I found interesting is that chemists use a set of rules to help them with ionic compounds and solubility in water. I also learned what a soluble is: a soluble is a ion compound that will dissolve in water, one that will not is called an insoluble. One thing I found interesting is that paints are made by crushing pigments and mixing them with water. Another interesting thing was that a majority of reaction that take place happen in water. Overall, this chem talk taught me many new things about color pigments, paints and precipitates, but I still feel like I have much to learn.