The Conclusion

The result of the electrolysis experiment was that no oxygen gas was produced, only hydrogen gas. This is because the chloride ions are oxidized in the reaction rather than the water oxidized to oxygen. Although the main goal of the project is not completed, the resulting hydrogen gas can be useful on multiple occasions. This will be discussed in the following sections. If this were to be scaled up for a full sized submarine, an extremely large amount of electric potential must be emitted to produce an adequate amount of products to be used. Also, the brine saltwater must be filtered to distilled water for oxygen gas to be produced. The amount of power that a nuclear submarine can emit makes electrolysis possible for breathable air. A nuclear submarine can produce about 150 standard cubic feet per hour of oxygen using electrolysis [7]. The tests showed that the reaction is not at all efficient and would need to be modified largely to become reasonable on large scale. 

Lab Number 9

The main issue at the moment is calculating the efficiency of the experiment. The problem is that a small amount of energy is being inputting into the system while a larger energy is being outputted. This is impossible since energy cannot be created. One solution is that the current could have been measured incorrectly. We will use another multimeter to measure the current to get an accurate reading to fix the calculations.

Lab Number 8

In today's lab, our group discussed the final report rough draft and what we can do to improve it. We broke down each section in the report and decided what information to add and remove. We also assigned roles to review and revise sections. The final construction will be completed next week as the materials will be purchased this weekend. We will run a few tests next week in larger scale with the finalized electrodes, copper. While constructing the final design, the last sections of the final project will be added. These will be equally distributed to each member of the group.

New Container

It was agreed upon in the group to shrink the system entirely. If we were to go large scale, and use the big plastic bin, an incredible amount of salt would be needed in order to have the solution to be just like saltwater. A smaller plastic bin with a lid was bought from a local hardware store. This will prove to be easier to operate with the system meaning a smaller amount of salt would be needed. The hole in the top of the lid needed to be machined in order for the alligator clamps to fit through. A 1/2 inch drill bit with the drill press was used at the machine shop to cut the lid.

The new and improved container. 

A larger hole was made for the alligator clamps to fit through.

Lab Number 7

In this lab, we were able to complete the efficiency experiment. Results and conclusions will be discussed at the end of this post.

Experiment setup:

Each reaction ran for an exact 60 seconds.

Copper

Aluminum

Oxygen gas actually visibly being produced on this electrode.

Steel

Titanium

 

Results

Conclusion

In each of the experiments, there is one common theme: there is actually no oxygen gas being created. This is the main goal of the design project and it seems that it cannot be done. In order for the reaction to go, there needs to be salt in the solution, however, this salt actually ionizes with the oxygen gas to create chlorine gas. The chlorine gas contaminates the water which is why it turns a greenish/yellow color. Overall, it was learned that the reaction cannot be done here to produce oxygen.

On the other hand, in each case a decent amount of hydrogen gas was produced. This can later be used in different reactions to not only produce oxygen, but possibly fire missiles or other possibilities. Hydrogen gas is extremely flammable and because of this trait, is useful for many reactions.

In conclusion, this was a extremely useful and important experiment. It took a while to complete, but all of the time spend was crucial for learning the experiment. We are happy that we have the knowledge that was learned from the efficiency experiment. 

Open Lab

On Wednesday, we were able to get lab time from 3pm-6pm. We set up the system using the steel electrode and a 1000 mL beaker. Sodium Chloride was added to the system as a catalyst to make the reaction go faster.

This is a picture of how the system looks. 

In this open lab period, we were able to experiment and learn about the reaction. Many small parts about the system went wrong from keeping the electrode in place, having water in the graduated cylinders, and the connections of the copper wire to the electrode. The lab time was needed to iron out these problems. Wednesday was a learning experience and allowed us to really learn about the reaction and how it works.

Sean stirring the salt in the water

A close up of the reaction.

On Thursday, Sean and Emily were able to get into the lab and continue the experiment. They learned that the connection between the copper wire and the electrode, although they were twisted on, were not solid and in result, hindered the reaction. They decided to use alligator clamps for a better connection and that improved the reaction tremendously.

Alligator clamps used

 This was a breakthrough in the experiment and allowed for the lab on Friday to go smoothly and for solid data to be recorded. In the Lab Week 7 post, the results of the experiment as well as conclusions will be discussed.

This is an example of how the experiment went. As it is seen, it is not the best setup for the reaction.

Lab Number 6

In week 6 lab, our group was able to go down into the Conservative Energy Laboratory and start with our experiment. The experiment wasn't exactly successful, but useful knowledge about the reaction and the process was gained.

We set up the experiment like this:

with one graduated cylinder on each stand and each clamps holding an electrode. It was soon found that this was an incorrect setup for the experiment but the reason why will be explained later. Copper wire was attached to the electrodes using electrical tape and was strung to each pole of the 6 volt battery. On a set time, the wires were applied to the battery and ... not much happened. After over a minute, all that was seen was minor bubbles. 

This indicated that the reaction started, but shortly afterward stopped. This was attempted multiple times but with each successive trial, there was no clear gas production volume. After help from Megan, we decided to add sodium chloride, or salt, to the solution to allow for a faster reaction. This did in fact help, as more bubbles were produced initially, but the reaction still did not continue. 

After scratching our heads and searching for possible answers, the solution struck us near the end of the lab time. We needed to complete the circuit not electrically, but chemically. This could be done in two ways. One being a salt bridge which maintains charge balance by allowing electrons to flow from anode to cathode and around the battery again. The reason why the reaction wasn't continuing was because the air was not able to transfer electrons throughout the two systems. By completing this circuit, the reaction should progress. 

An example salt bridge

The other way the reaction could continue is if we submerged the entire system in a salt-water solution. This makes the surrounding salt-water the salt bridge in which electrons could flow, therefor driving the reaction. 

Kind of like this, in a way.

The sodium chloride used would be a catalyst for the reaction, in result speeding it up. There is concern that chlorine gas would be produced, but this is a chance that we would have to take.  

With this knowledge, we will get into the lab on our own time this week to complete the experiment before lab Friday. This will be done to discover which electrode is the most efficient. 

Materials Came In

This week, a portion of our materials came in which were ordered from McMasterCarr.com. We received, all in one foot, 1/4 inch diameter dimensions, a steel rod, aluminum rod, copper rod, titanium rod and four graduated cylinders. The exact specifications are as listed:

• Low-Carbon Steel Rod
• Multipurpose 6061 Aluminum Rod
• High-Strength 182 Copper Rod
• Ultra-Corrosion-Resistant Titanium (Grade 2)
• 25 mL Plastic Graduated Cylinder, 6-5/8 inch tall (0.5 mL increments) 

Copper Rod

Titanium Rod

Graduated Cylinder

Since the rods came in each with a 12 inch length, they needed to be cut down to fit the 3 inch requirement. A metal cutting Band Saw was used at the Drexel Machine Shop.

The Band Saw in action

 Correct markings were made and the metals were carefully cut in half, then in half again. 

Examples of the measurement markings on the Titanium rods

After they were cut, a belt-fed sander was used to smooth the rough edges to prevent injury. 

Titanium Rod before

Titanium Rod after

The Band Saw cut all the metals with ease, except for the Titanium rod which took at least 10-15 minutes per cut (while other metals took 30-60 seconds). 

The Titanium rod took 15 minutes to cut per cut

Nevertheless, the rods were cut to the required length.

Finished Copper Rods

Finished Titanium Rods

Finished Steel Rods

Finished Aluminum Rod

Lab Number 5

Materials are on the way!

• Graduated cylinders are ordered
• Final electrode list has been made, needs to be finalized. 

• Type	Diameter (in)	Length (in)	Price
  Graduated Cylinder	1	7 7.0/8.0	$10.87
  Steel Unpolished	1.0/2.0	12	$3.06
  Aluminum Unpolished	1.0/2.0	12	$3.19
  Titanium	1.0/2.0	6	$20.11
  Copper Unpolished	1.0/2.0	12	$14.80

Once we get these materials in, we can proceed with our experiment (using the multimeter) and finalize which electrode will be used. Each electrode should be 1/4 inch in diameter and 3 inches long for the test and experiment. It is important that the surface area and connection to each electrode is identical throughout each pair. A challenge will be cutting each metal accurately.

The Final System

Once we physically get the materials, we will finalize on the size of the system. The material should be aluminum, but any easily malleable substance will be used. An acrylic window will be used to view the reaction. We have an idea to make this window accessible by using a latch. This will be challenging because when close, it needs to be water proof. A solution to this may be a rubber piece, but we are unsure at this point.    

Electrolysis of Water

Below are the chemical equations that were used in the energy production proof here. It proves how much Voltage, or activation energy, to allow the reaction to go.

2 H₂O(l) --> 2 H₂(g) + O₂(g)

2 H2O + 2 e- --> H2 + 2 OH-			Eored = -0.83 V
2 H2O --> O2 + 4 H+ + 4 e-			Eoox = -1.23 V

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch20/faraday.php


"Electrochemistry." Electrolytic Cells. Bodner Research Web, n.d. Web. 28 Apr. 2014.

The Science behind Electrodes

Electrolysis cells

Below is a brief description of how the electrodes should work. One end will be hooked up to the positive end of the battery while the other to the negative end of the battery.

The electrolytic cell has two (usually inert) electrodes to pass the electric current into the electrolyte. The negative electrode is called the cathode and the positive electrode is called the anode. The inert electrodes are usually made of graphite or platinum wire. The reactions occur at the surface of the electrodes. The power supply is usually symbolized by a short fat line (negative) and a long thin line (positive)

http://ibchem.com/IB/ibnotes/full/red_htm/9.5.htm

"Electrolytic Cells." Oxidation and Reduction. IsisSoft Interactive, n.d. Web. 28 Apr. 2014.