Calibration of a pH Spectrum LAB - Corrigan

Last Friday in Mr. Wong's class we conducted a lab about the effects of sodium hydroxide, a base, and hydroelectric acid on cabbage juice. Cabbage juice is special because when you add to it it changes color and indicate the pH of the new solution. 

Table info:

Tube 1 (Just the Cabbage Juice)

pH of Cabbage Juice: 7.45

Color of juice is purple

Test Tube 2

1 drop more of HCl for -1 pH change to 6.6

Lighter Purple

Test Tube 3:

5 drops more of HCl for -2 pH change to 5.5

Darker Pink

Test Tube 4

11 drops more of HCl for -3 pH change to 4.5

Light Pink

Part C:

7.5 initial pH (Just Cabbage Juice)

Color Purplish Blue

Test Tube 5:

2 drop more of NaOH to raise to 8.6 pH

Teal

Test Tube 6:

7 drops more of NaOH to raise to 9.4

Greenish Teal

Test Tube 7:

7 drops more of NaOH to raise to 10.42 pH

Dark Green

Graphs:

Analysis Questions:

4. I would say for our lab, the drops of base had more of an effect on the pH. This is because less drops of the base had a greater effect on the cabbage juice than the acidic drops did. 

5. I learned pH can be swayed depending the pH of other solutions when added to a central solution. Overall the lab was fun and I liked the cool colors the were the result. I had no idea that you could change the color of cabbage juice do significantly so easily! Below is our picture of our juice color spectrum and a picture of our materials used.

Pressure in Popcorn - Lab

Last Friday, we had a chemistry lab all about popcorn. We were given the task to calculate the pressure (ATM) of  popcorn kernels through the popping process. All kernel have some water in them as wheel. We started with around 40 kernels and measured the volume by displacing water. Then we poured a small amount of cooking oil into a beaker and then followed up by placing our kernels in after. We proceeded to use a gas burner to heat up the bottom of the beaker until most of the Kernel were popped without burning the popped ones to ash. We weighed the beaker before and after and used all of the data together to get our answer. 

Stats:

Initial Volume: 4.9 ml

New Volume:  10.4 mL

40 kernels

37 kernels

Pre Pop Mass: 111.21  g

Post Pop Mass: 109.54 g

225 degrees Celsius

Math:

5.5 ml

111.21 / 109.54

1.67 x 1 / 18 = 0.093 mole

P = nRT / v 

(0.093)(0.0821)(498) / .0055 = 691.3 / 37

18.68 ATM

I am guessing all of the kernels did not pop because they all did not have the same amount of surface area being burned at the same time. Time was crucial because we could not let the quick popping pop corn burn while we waited for un-popped kernels to pop. Because all of the kernels did not pop this could have affected the weight before and after. This could have skewed the data slightly. 

Lab - Lets make a Rocket - Corrigan

Last Friday, Mr. Wong's 6th period class attempted to use our knowledge of gas laws to launch Coke and mentos rockets. The reason a rocket like this would launch would be because of a physical reaction. I call it this because during the reaction the coke remains coke and the mentos stay mentos. When the mentos go into the Coke, they make the coke fizz excessively with CO2 because the Coke is carbonated in the first place. Because of the cork sealing off the exit for the CO2, the pressure builds up in the bottle until it bursts through cause the rocket to take flight. At least this is how it is supposed to work. Our rocket did not have such a glorious launch. As you can see in the video below, we sealed the bottle so tight that it couldn't burst without Mr. Wong throwing it into the air. When he does this the angle of trajectory goes from vertical to horizontal and we are unable to really tell how high our rocket could have launched. When it comes to gas laws, my group believes boyels law was in effect, because the P1 and V2 were represented by the coke before the montos, and then after the new P2 and V2 were discovered. For next time, I think it would have been better to tighten the cork just enough but to much like we did in our first attempt. This would allow the rocket to shoot up by itself without outside assistance, hopefully improving the height reached.

Here is our video, please enjoy:
https://youtu.be/bynNE9GLPOQ

Limiting Reagent Lab Activity - Corrigan

This time in Mr. Wong's 6th period chemistry class we investigated the reactions of vinegar and baking soda. We used math to determine the limiting reagent when using different amounts of baking soda and measuring the circumference of balloons!

Below is a excel spreadsheet of our data and results:

Here are some pictures of us conducting the experiment:

Analysis Questions

1. What are the limiting and excess reagents for each flask?

The excess reagent was the baking soda and the excess reagent was the vinegar. We were able to conclude this by noticing that there was vinegar left over but all of the baking soda had been used up in the reaction.

2. How is the amount of product in a reaction affected by an insufficient quantity of any of the reactants (reagents)?
According to the law of conservation of mass, there will always be the same amount matter on the reactants side as the products side. Because of this when there is less reactants the out come will be less as well.
3. Which balloon was the largest? Explain.
The green balloon was the largest because that was the flask we put the most baking soda into (4 g). With the vinegar this caused the largest reaction. The reactants where large so the products where as well.
4. Which balloon was the smallest? Explain.
The smallest balloon was blue because it had the least amount of baking soda go into it (1 g). There was an excess of vinegar. Because the reactants were small the products where also small.
5. Rust is produced when iron reacts with oxygen. How many grams of Fe2O3 are produced when 12.0 g of iron rusts?4Fe(s) + 3O2(g) → 2Fe2O3(s)
81.6 grams are produced.
6. What real-life applications can this concept of limiting and excess reagents be applied to?
This idea can be applied to making sandwiches. For instance, if you need 1 meat and two bread in order to make one sandwich and you had 100 bread but only 5 meat, then you can only make 5 sandwiches even though you will have a lot of bread left over.