Week 7

Hey Guys!

This week was spent focusing on trying to collect the Hydrogen gas that was produced by my device.

I went to the lab and talked to my professor about the issue and he suggested I try to increase the current output by putting more batteries in series. He also suggested I try to increase the water level so that there is less air in the container and so that it is more easily pressurized. He gave me some 1.5 Volt batteries, an old charger he didn’t need anymore and left me to work.

First thing I did was found some scissors and cut up the old charger into wires. I cut back the insulation so that the metal would be exposed to the batteries and made a set of mini wires I could use to connect the batteries. I didn’t have anything to hold the wires in place (I wouldn’t be able to hold all of them manually while I ran the experiment) so I found some parafilm and used it to tie the wires down onto the batteries, and then tie all of the batteries together. Together they made a much larger battery.

                      

Before I tested the new battery I increased the water level to 1000 mL and added a 1/4tsp of salt to keep the concentration of salt the same as before.

After preparing the solution, I tried the larger battery that I had created on my device. It contained four 1.5 volt batteries connected together in parallel. After wiring the battery to my device, I observed that there were no bubbles forming.

I then changed the set up of the battery and connected 2 batteries in parallel and connected it in series to another 2 batteries in parallel. The setup gave me 3 Volts instead of 1.5 as before. When testing it, I found that this time bubbles did form and gas was produced. The reaction however was still less severe than that of my 9 Volt battery.

I then sought some help from my graduate lab partners and they used a device called a potential state to check for the minimum voltage needed to start the reaction. To use the device, a range of different voltages are tested and the resulting current is measured.

 After experimenting we concluded from the graph above that the minimum voltage needed to start the reaction was 3 Volts because there was a drop in the rate of current increase at this location. At this point is where water begins to split. The reduction reaction uses the electrons to create the hydrogen gas causing a drop in the rate of current increase even with increasing voltage.  The graph also explained why the 1.5 volt batteries all in series did not work (we had not reached the minimum voltage required). 

I then tried using four 9 Volt batteries instead of 1.5 Volts to see if I could collect anything with the same setup (2 in parallel connected in series to another 2 in parallel) and left the device for an hour. After time was up there was still no change in the shape of the balloon and so I decided that I would have to change the brand of caulk I was using and check for any other leakages elsewhere.