3 Question March 28

This week was Spring break! I played a lot of tennis to keep myself in shape because my tennis state is only two months away! I also worked on a lot of applications. NMSBA testing really wore me out last week. We missed out on a lot of class time so we had some catching up to do at home.  We did have a few UT online homeworks due on the current section which is dealing with molecular equations. Until next week! 

Air Bags

Almost every individual has been accompanied by an airbag. Have you ever wondered just how these bags of air can protect you from the most devastating car wreck? First, the air bag is made out of nylon fabric that has a sensor that tells it when exactly to inflate. Well when is it supposed to inflate, and how does it do so? Well the sensor detects a collision force up to 15 miles an hour and that is when it then inflates. The inflation process then occurs. During this process sodium azide (NaN3) and potassium nitrate (KNO3) create a large sum of nitrogen gas which practically explodes out of the different parts of the car. Then immediately after it already starts deflating through holes so the passenger can make it safely out of the car. This is simple chemistry believe it or not! Car producers are using gas laws to equip their cars with air bags. A current heats up the chemicals causing a chemical reaction. As the temperature increases, the particles begin to move faster just like with any other gas. As the particles move faster the volume increases which inflates the bag. This can also be shown on the PHET simulation worksheet we did in class. Air bags used simple chemistry to help save millions of people’s lives that are involved in automobile accidents. What will science lead us to next? 

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Sources: 

http://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/question130.htm

http://www.chemistry.wustl.edu/~edudev/LabTutorials/Airbags/airbags.html

Class Notes

3 questions May 9

This week I was gone to state all week for tennis. It was a very dramatic and thrilling occasion. My partner actually hit my in the eye with her tennis racket. I also cause an opponent to have a asthma attack which was very scary because she collapsed. I am going to try to catch up in chemistry as much as possible because I want an A in the class. Until next week!

Gas Laws

Gasses are different than both liquids and solids because their particles move freely in any space that the gas is given. If it is given a lot of space the gas particles are going to expand as far as they can. In the case of our explore lab we set up a funnel with a cord that was attached to a jar with a rubber stopper. This stopper ensured that no air would penetrate the gas and cause more air to be in the jar. As we added water through the funnel, the water began to take up the space that was once occupied by the spread out gas particles. As the water increased the pressure of the gas increased which eventually caused no more water to be able to enter the jar because the pressure was too high and the volume of the jar was already occupied. Solid particles have a set frame and stay close together unlike gas particles. We did this experiment at three different heights: low, medium, and high. The highest volume had the most pressure in the jar because the water was able to flow straight down into the jar. The lowest one had a pressure of 735.9mm Hg, which was low because the water had to “work” harder to get into the jar due to the excess tubing. A relationship began to form in front of my little chemist eyes. The less volume of air there was the more pressure it had because the particles were bouncing off each other more often! There was more particles in a more confined space which made the pressure rise! 

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http://chemwiki.ucdavis.edu/@api/deki/files/17426/a433792ac2caa29995f55547b9d15918.jpg?revision=1

Sources: 

Class Notes

Explore Lab/Data 

Who Cares about Titration?

Titration is used in industries because it enables quick determination of concentration of unknown solution. This process helps determine if a certain substance is neutralized or not. You can use a pH indicator to help. Once the color of the indicator changes accordingly then you have neutralized your solution. Here’s how it works!

First, prepare a buret.

Next, take your volume of solution you are using. 

Then you can put your amount of solution in a beaker or flask. Add a magnetic stirrer and an indicator which will tell you once the solution is neutralized. 

Next, slowly start letting your base drip into the acid. Watch this carefully because the color can change completely with one extra drop of base. Once you believe you have reached your end point you can take a distilled water squeeze bottle and rinse the sides of the beaker or flask to make sure all of the solution is together.  

Now, measure how much base you added to the acid and you can now figure out the concentration using M1V1=M2V2. In this equation plug in the initial molarity and volume of the known solution and set it equal to M2V2 which is the amount of volume in the buret after you finished times the molarity (which is what you are trying to figure out) and solve for M2!

In other words if you needed to figure out how much citric acid was in fruit juice the process would be the same! 

1) You would use ammonia to figure this out! So fill a buret with ammonia and place it on the buret clamp!

2) Then, measure out 50 mL of the fruit juice you are experimenting with and place it in an Erlenmeyer flask. 

3) Place 3 drops of your indicator, phenolphthalein, into the fruit juice! (this indicator will turn light pink when the solution is neutralized) 

4) Add ammonia from the buret into the flask until the color of the juice turns from pink to very very light pink. If the solution turns clear you have gone too far. 

5) Now all that is left is to do the M1V1=M2V2 calculations and you have determined the amount of citric acid in the fruit juice!

Sources: 

Notes

Class Lab

http://www.dartmouth.edu/~chemlab/techniques/titration.html

http://www.ask.com/question/why-is-titration-used-in-industry

Cool Reactions

Number 10) Sodium and Chlorine Gas: 2Na +Cl2 —> 2NaCl

This is a chemical reaction because it lit on fire. This also means it was a combustion reaction.

Number 9) 2Mg + CO2 = 2MgO + C. This is a chemical reaction because it is combustion because it has a flame. It is a single replacement chemical reaction. 

Number 8) KClO3+ C6H12O6 —> 6CO2 +4KCl + 6H2O Yes this is a chemical reaction because it is producing something that was not already there. It produced a salt, CO2 and H2O making is a gas producing metathesis reaction.

Number 7) This is not a chemical reaction because the temperature is changing. Therefore there is no chemical equation.

Number 6) This is not a chemical reaction because it is changing states. State change indicates only a physical reaction. It also says the temperature rises, but that also does not mean its a chemical reaction.

Number 5) This is not a chemical reaction either. This reaction is not producing any type of precipitate which means it simply cannot be a chemical reaction.

Number 4) This is not a chemical reaction because it is not reacting with anything or forming anything new. It simply lowers the human voice and that does not make it a chemical reaction.

Number 3) This is not a chemical reaction. This is just describing helium; therefore, nothing is combined with it, and nothing reacts.

Number 2) This reaction is indeed a chemical reaction because it produced smoke and lights on fire. It is a single replacement reaction. Fe2O3 + 2Al –> Al2O3 + 2Fe.

Number 1) This is a chemical reaction because there is a color change, which could really indicate both, but there is also a smell he describes that is produced which positively indicates a chemical reaction. Although this is a chemical reaction I cannot write an equation for it because of the lack of information the video gave.

Personally my favorite was the hexafluoride demonstration. I thought it was neat to see how that reacted just like water would even though its a gas. Also it makes your voice extremely deep which got a few chuckles out of me.

This is another dry ice demonstration that I thought looked cool and was worth sharing.

The main source I utilized for this blog was the Top 10 amazing chemical reactions site which is listed below!

Top 10 Amazing Chemical Reactions