Calibration of a pH spectrum

In this lab, we created a spectrum of colors by adding various amounts of drops of acids and bases to some red cabbage juice. By adding the acids and bases to the cabbage juice, we can visually see the different colors that represent the different pHs of the liquids.

First, we filled some test tubes with some of the cabbage juice. Then we added a few drops of the acid or base. With the pH paper, we could then figure out the value of the pH that correlated with the color of the cabbage and the acid/base. In this lab, we used hydrochloric acid and we used sodium hydroxide.

Here is a picture of our end results:

As you can see, we went above the required amount and decided to make a full-color spectrum with the chemicals that we had.

Here is our data

In tube #1 there were 6 drops of HCl added. This had a pH of 2. This had a color of dark red.

In tube #2 there were 5 drops of HCl added. This had a pH of 2. This had a color of red

In tube #3 there were 4 drops of HCl added. This had a pH of 3. This had a color of crimson.

In tube #4 there were 3 drops of HCl added. This had a pH of 4. This had a color of violet.

In tube #5 there were 2 drops of HCl added. This had a pH of 5. This had a color of pink-violet.

In tube #6 there were 1 drops of HCl added. This had a pH of 6. This had a color of pink.

In tube #7 there was nothing added. This had a pH of 7. This had a color of purple.

In tube #8 there were 1 drops of NaOH added. This had a pH of 8. This had a color of teal.

In tube #9 there were 2 drops of NaOH added. This had a pH of 9. This had a color of turquoise.

In tube #8 there were 3 drops of NaOH added. This had a pH of 10. This had a color of light green.

In tube #9 there were 4 drops of NaOH added. This had a pH of 11. This had a color of chartreuse.

In tube #8 there were 5 drops of NaOH added. This had a pH of 12. This had a color of lime green.

In tube #9 there were 6 drops of NaOH added. This had a pH of 13. This had a color of yellow-green.

Here is a graph of all of these results:

The x-axis is the number of drops

The y-axis is the pH.

 

Questions: Which drops (acid or base) caused a more dramatic change in the pH
of the solution? Why?

The bases had a more profound change to the colors. The bases immediately changed the purple color to a teal. This was also reflective of the pH paper, as it had a more profound change.

My learnings: This lab taught me that you can visualize acids and bases through a pigment in cabbages. Also, I learned that the higher the acidity, the lower the pH is, and the more basic it is, the higher the pH is. This was probably my most favorite lab of the year.

Pressure in Popcorn Lab

In this lab, we attempted to find the pressure necessary to pop a kernel of popcorn. We started by measuring the volume of 30 kernels. Next, we placed the kernels into 1.5 mL of vegetable oil. We then gathered the total mass of the beaker, 30 kernels, and 1.5 mL of vegetable oil. We lit the bunsen burner and placed the beaker on top of the ring stand. After all of the kernels were popped, we eliminated the unpopped ones and gathered the data from this lab.

Here is what the setup looked like:

Here is what the popping looked like (credit to Justin Le)

The volume of 30 kernels is about 3.9 mL and we added 1.5 mL of oil. The mass of the beaker and its contents weighed 113.8 grams. After popping the popcorn, the final mass weighed only 102.3 grams meaning that 11.5 grams of water evaporated from the inside of the kernels Very surprisingly 30/30 of our popcorn popped!

We found the mass by using this formula:

We then took the moles and put them into PV=nRT to get:

 

This got me to 7.5 atm for the pressure to pop popcorn

 

Questions and Answers:

1) The volume of 30 popcorn kernels 3.9 mL or .0039 L

2) The total mass is 11.5 g of water

3) There are .21 moles of water released per kernel

4) See above work. 7.5 atm is what I got.

5) Normal atmospheric pressure is 1 atm, while it takes about 7.5 atm to pop a kernel of popcorn. That’s a big difference!

6) Some didn’t have enough water for the H2O to turn into water vapor. They couldn’t expand enough to pop.

7) The temperature might have been an issue because we were given a value, and we didn’t measure it ourselves. There also might be errors in the calculations.

 

Let’s make a ROCKET

 

In the Diet Coke and Mentos Lab, we first prepared our base by cutting half of an empty bottle and setting in down into the tray. We then took 5 mentos and connected them to a sharp nail. We poked that nail into a cork and then inserted it into the bottle hole. When we were ready, we flipped the entire bottle upside down and stuck it into the base. The pressure from the CO2 in the bottle had enough power to propel the bottle in an upward motion. This is how we made our rocket.

Here is a step by step picture:

Questions

Reference any chemical/physical reaction that may have occurred

The diet coke and mentos experiment is a physical reaction.

All the carbon dioxide in the soda that is squeezed into the liquid wants to escape. Additionally, the CO2 clings on to any tiny bumps that it can grab onto. Those tiny bumps are called nucleation sites: places the gas can grab onto and start forming bubbles. Nucleation sites can be are anywhere that there is a high surface area in a very small volume. The surface of a Mentos is sprayed with layers of liquid sugar. That makes it not only sweet but also covered with lots and lots of nucleation sites. In other words, there are so many microscopic areas on the surface of a Mentos that an incredible number of bubbles will form around the Mentos when you drop it into a bottle of soda. Since the Mentos are also heavy enough to sink, they react with the soda all the way to the bottom. The escaping bubbles quickly turn into a raging foam, and the pressure builds dramatically.

This is why it launched!

 

Thoughts on WHY the rocket launched

All of the CO2 in the soda was immediately released causing a load of pressure to escape from the bottom when the cork busted out.

 

How any gas laws are involved

Boyle’s Laws is involved. When the mentos react with the mentos, the pressure in the bottle rises to a higher level than the outside compressing the coke in the bottle. Once it is released into normal atmospheric pressure the coke rises in volume and the pressure is lost as it is propelled upward.

 

Ideas of what went wrong or what could improve the launch

I think the cork didn’t allow for a powerful launch. The cork wasn’t really completing a good seal, thus the rocket didn’t build up very much pressure.

I am also curious whether or not fruit flavored mentos will have a different reaction than the mint flavored ones.

 

Lastly, I leave you with a video of what the reaction looked like. Unfortunately, the cameraman in our team wasn’t prepared, so we have a quick representation of what the reaction looked like. Sorry for not catching the rocket on camera.

Limiting Reagent Lab Activity

 

In this lab, we put varying amounts of baking soda into a balloon and poured it into an Erlenmeyer flask which was filled with 50 mL vinegar. This reaction created baking soda and made the balloon become filled with gas. We were experimenting to see what combination would produce the most CO2.

The setup of the lab looked like this:

Here is a video of the demonstration:

Here is the data of the experiment:

The Light Blue Balloon enlarged to have a circumference of 20 cm, and a total of 134.7 cm^3 of CO2. It had a total of  .52g of CO2.

The Blue Balloon enlarged to have a circumference of 32 cm, and a total of 552.39 cm^3 of CO2. It had a total of  1.04g of CO2.

The Red Balloon enlarged to have a circumference of 37 cm, and a total of 855.92 cm^3 of CO2. It had a total of  2.1g of CO2.

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This is what’s happening:

CH3COOH + NaHCO3 = CH3COONa + CO2 + H2O

Acetic Acid and Sodium Bicarbonate yields to Sodium acetate, Carbon Dioxide, and Water

Analysis questions:

1. What are the limiting and excess reagents for each flask? How did you determine this?

The limiting reagent is the substance that is totally consumed. The excess is the substance that is too much. You know this because if there is excess, that is the excess reagent, and if there is not enough, it is the limiting.
2. How is the amount of product in a reaction affected by an insufficient quantity of any of the reactants?

If there is not enough of a substance to completely react, the product will have less of a quantity.
3. Which balloon was the largest? Explain.

The largest was the balloon with 4.0 grams of baking soda. This has the most sodium bicarbonate out of all the balloons.
4. Which balloon was the smallest? Explain.

The smallest was the balloon with 1 gram of baking soda. The baking soda was the limiting reagent.
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)

About 17.4 grams.
6. What real-life applications can this concept of limiting and excess reagents be applied to?

You can understand how basic substances and combine to create a new product. This teaches us how there are different amounts of a product, based on the amount of the reactants.

Alternate Penny Battery – Lemon Battery

In this extra credit assignment, my father and I worked together to make a Lemon Battery!

Here are the materials that we used:

2 Lemons,  2 pieces of copper wire, 2 zinc paperclips, a double ended alligator wire clip, an LED, and a voltmeter.

We started by squishing the lemon to release the electrolytes from the small bulbs of juice. We then inserted a zinc paper clip and a piece of copper wire into the lemon. Next, we did the exact same steps to another lemon. We then connected the zinc terminal from one lemon onto the copper terminal on the other lemon. Then, we connected the remaining terminals to a voltmeter or a LED.

Our results were better than expected, and we were getting about 2 volts from our battery. We were even able to power an LED!

Electrolyte Type: The type of the electrolyte was the juice inside of the lemon.

What I learned: I learned that I can make a battery, capable of powering a small LED out of household materials. I also learned that different materials work better for my battery. I first used a galvanized nail for my zinc source but found out that a zinc paper clip generated more electricity than the nail. I also learned that in a lemon battery, both oxidation (loss of electrons) and reduction (gain of electrons) occurs.

The process is like this:

At the anode, metallic zinc is oxidized, and enters the acidic solution as Zn²⁺ ions:

Zn –> Zn2 + + 2 e-

At the copper cathode, hydrogen ions are reduced to form molecular hydrogen:

2H++ 2e- –> H2

 

Penny Battery

In this lab, we made a battery out of pennies cardboard, vinegar, salt, and water.

Procedure: To begin, we sanded off one face of 4 pennies. We then soaked some pieces of cardboard into a solution of salty water with a splash of vinegar. Next, we stacked the soaked cardboard on top of the shiny side of the penny. We put everything together and put a penny on top. Our cell was complete. We finished by testing it by connecting an LED light to it. The LED light shined up.

Type of electrolyte: I believe the matboard soaked in salty vinegar water serves as the electrolyte between the two terminals.

This is what is happening: When the two different metals are connected by an electrolyte, a chemical reaction occurs at each metal surface, called electrodes, that either produces or uses electrons. When these electrodes are connected by a wire, electrons will move from one surface to the other, creating an electric current.

Here is a good diagram:

Here are some cool pictures that were taken with the help of our great teacher Mr. Wong:

Construction:

End Result:

End Notes: I am very curious whether the electrolyte used will affect the battery’s strength. Maybe if we use some industrial grade chemicals, the battery will last longer/produce a higher voltage. This was a fun, quick, and simple lab, in which I got a better understanding of electricity.

Reactivity of Metals

Here is the data table that we gathered:

Sodium 11.05 seconds to dissolve

Metal was a whitish color. It than vigorously bubbled and turned the solution blue. Dark blue after the reaction

 

Lithium 42.04 seconds to dissolve

Metal was a darkish black color. It has a similar effect as sodium, but it took a longer time. Lighter blue.

 

Calcium 14.51 seconds to dissolve

Shiny dark metal. Fast reaction, but took a long time to dissolve into the water. The solution is a very milky and bubbly blue color. It is foamy at the top and a very light blue.

 

Aluminum Several hours/days to dissolve

Shiny reflective metal. Very slow reaction with little action. The end result was a still red color.

 

Magnesium Several hours to dissolve

Grey metal. Slow reaction very similar to aluminum. Little action during the reaction. It became a purple color with hints of green.

 

Here are the pictures of the metals before the experiment:

Here are the pictures of our metals when they are reacting to the water.

Here is Calcium:

Here is Sodium:

Here is Lithium:

Here is Aluminum:

Here is Magnesium:

 

Lastly, here is a picture of the aluminum that took an incredible time to dissolve. It sunk down to the bottom of the test tube.

 

What I learned

In class, we learned that metals on the left side of the periodic table can react with water in order to be more like the noble gasses on the right side of the table. I learned that the gas produced is hydrogen and that the liquid is a form of hydroxide. I also learned that metals like potassium and sodium have the potential to catch fire or even explode. Since the metal is producing hydrogen gas, it is very flammable.  I learned that a chemical reaction occurs when you mix certain elements with other elements/compounds. Sometimes during these reactions can be violent like the sodium and water, or they can be very slow and calm like aluminum and water.

Be on the lookout!

 

1 The number of alien fingers increases as you move down a column or along a row from left to right

2 Aliens will have a similar body pattern when in the same group.

3 Aliens will have an increasing body weight the farther down on the chart they are

4 Aliens will smile when they are closer to the group on the right.

5 Aliens will have additional arms when they run out of fingers for that hand

6 Aliens have more curls when their hands have 8 fingers

7 Aliens in a column like to eat more humans as you move from top to bottom.

8 Aliens on the left of the chart want to be like the aliens on the right because they aliens on the right have all of their fingers.

Periodic Mendaliens

Here is Alex Cala’s and my (Jacob Brandis) table.

 

I hope you like our new alien. I added additional features to make it correct.

 

1. In what TWO ways are all the species different?

Each Alien has a different amount of fingers.
2. What do the species in a ROW have in common?

Each species in a row has the same body size and number of arms. Top has skinny aliens, middle has medium weighted aliens, and the bottom have fat aliens. Top has one arm, middle has 2, and third have 3 arms. This represents the periods.
3. What do the species in a COLUMN have in common?

From column, they have different body pattern. For example, Some have triangles or spots. These are the groups
4. How do the numbers of fingers relate to the periodic table?

The number of fingers represent the atomic number of each element. One finger is hydrogen, and so on.
5. How do the arms relate to the periodic table?

The arms show the number of the period that they are in. 1 arm means they are in period 1.

6. How do the number of hairs relate to the periodic table?

The hairs represent the group of each alien. 1 hair means that they are in group 1.
7. How do the markings on the chest identify the agents compared to the periodic table? The marks on the chest represent the group.

problem-solving lab: interpret scientific illustrations

Calculate: Here is what my partner and I typed into the calculator.

1)1524129.3845^-1 nm

2)2057574.6691^-1 nm

3)2304483.6294^-1 nm

4)2438607.0152^-1 nm

In this lab, I learned that the Rydberg’s constant is used to find the wavelength of electrons. The Rydberg Constant is 1.09678*10^7 (1/nf^2-1/ni^2)m^-1. By using this formula, you take an electron orbit transition and have the ability to calculate the wavelength.