Introduction

This is an example of our experiment:

Polymerization: what happens in the reaction? 

The principal compound in this experiment is called p-nitroaniline, a yellow or brown color chemical compound, which formula is C6H6N2O2 . It is very toxic for ingestion and inhalation and it must be used with much care, using always goggles and mask. 

The objective of this project is to provoke a p-nitroaniline polymerization and study and investigate it. A polymerization consists on, through a chemical process or reaction, transforming monomer molecules grouped together into polymer chains or three dimensional structures. 

There are many different types of polymerization, but the one that takes place in our experiment is an explosive polymerization. What occurs is a decomposition reaction between p-nitroaniline and sulfuric acid, with temperatures over 200ºC. It has been studied by the NASA because of its ability to form pyrostat, a substance that extinguishes fire. It is a solid black foam, which density varies depending on how expanded the foam is and depending on the quantities of substance used in the experiment. I believe that in a near future, this substance, produced in great quantities, could be used by fire departments, or even in domestic fire extinguishers in case of emergency. However, I think that there are cheaper ways to create materials for fire extinguishers, but this black foam could be an option.

Objective

The objective of our experiment is to proof if there is any kind of relationship between the height of the resulting black-foam structure and the amount of p-nitro aniline (C6H6N2O2) that reacts with a constant amount of hydrosulfuric acid (H2SO4)

Hypothesis

Whenever the amount of solute changes we will appreciate a direct relationship between the volume  of the resulting foam structure and the amount of solute (p-nitroaniline) in the solution (p-nitroaniline and hydrosulfuric acid).

Variables

• Dependent variable: The resulting foam structure 
• Independent variable: The amount of p-nitroaniline for each trial
• Controlled variable: Amount of sulphuric acid (5ml), the container in which the reaction takes place and the concentration of the hydrosulfuric acid. 

Materials

• Sulfuric acid:
• 

To work out the molarity of the sulphuric acid knowing that the concentration is 96% and that the density in one litre is of 1840g, we work out the mass and divide it by the molecular mass.

96% of 1840= 1766,4g

Molarity= 1766,4/ 98,07= 18,011 g/mol

• P-nitroaniline
• Spoon
• Scale
• Bunsen burner
• Tripod for the bunsen burner
• Pipette 
• Goggles
• Masks
• Flask
• Small bowl (container)

Method of the experiment

    After collecting the materials we will follow the next procedure:

• Measure the amount in grams of p-nitro aniline for that particular case: we will be making 5 trials by each measurement, in order to obtain reliable data. These are the seven amounts of p-nitro aniline (g): 5; 6; 7; 8; 9; 10; 11.
• Connect the bunsen burner until a visible (between blue and orange colour) flame appears.
• After having measured the amount of p-nitro aniline, we will place the small bowl on top of the bunsen burner and spill 5 ml of hydrosulfuric acid H2SO4.
• Wait until it heats up and the reaction takes place.
• After exploding we will measure the height of the black-foam structure from one of its sides, so that if it is tilted we won't take into account the difference in the curve. We will ass well measure the diameter of the black-foam structure (for this take a bottom measurement of the structure and one from the top of it and make an avarage), that will be very similar to a cylinder.
• Make a table with the collected data.
• Calculate the aproximate volume for each black-foam structure, through this formula:

• Finally observe if there is a direct relationship between the amount of p-nitro aniline and the aproximate volume of the black-foam structure, that will increase every time more p-nitro aniline reacts with the hydrosulfuric acid.

Bibliography

• Es.wikipedia.org,. (2014). P-nitroanilina. Retrieved 17 November 2014, from http://es.wikipedia.org/wiki/P-nitroanilina
• Wikihow.com,. (2014). Volume of a Cylinder Cheat Sheet - wikiHow. Retrieved 17 November 2014, from http://www.wikihow.com/Sample/Volume-of-a-Cylinder-Diagram
• YouTube,. (2014). EXP 1. Explosive Polymerization of p Nitro Aniline. Retrieved 17 November 2014, from https://www.youtube.com/watch?v=h4pNXAtPJp8
• Poshkus, A., & Parker, J. (1970). Studies on nitroaniline–sulfuric acid compositions: Aphrogenic pyrostats. Journal Of Applied Polymer Science, 14(8), 2049-2064. doi:10.1002/app.1970.070140813

Es.wikipedia.org,. (2014). P-nitroanilina. Retrieved 17 November 2014, from http://es.wikipedia.org/wiki/P-nitroanilina

On this web page we have all the information of the P-nitroaniline. Here, on the web we have the chemical components and everything in relation with P-nitroaniline, for example observing this web page we know that P-nitroaniline is used for some medicines and also for fuel. Also on this web we have some theory about the toxic things of the P-nitroaniline. The bad part about this web page is the main web page, I mean, this information is located on Wikipedia, and there the information is not 100% truthful.  

Wikihow.com,. (2014). Volume of a Cylinder Cheat Sheet - wikiHow. Retrieved 17 November 2014, from http://www.wikihow.com/Sample/Volume-of-a-Cylinder-Diagram

By looking this web page, we see that on this one, appears two perfect diagrams, in those diagrams we have a cylinder or beaker. During the experiment we are going to calculate the area of a cylinder, I mean, after the explosion, the resultant piece of carbon looks like a cylinder, so this web page may be very useful. I really don´t like that on this web page is all explained by diagrams, and sincerely I prefer that things like that must be explained using theory.

YouTube,. (2014). EXP 1. Explosive Polymerization of p Nitro Aniline. Retrieved 17 November 2014, from https://www.youtube.com/watch?v=h4pNXAtPJp8

On this web page we have the video of a explosion using nitroaniline. We decided to do this experiment because of this video. It is a very good video, and we thought that we can do it. By watching the video we knew how to do the experiment. What we really dislike about the video, is that it is a simple video, no more, and for doing this experiment we need many different data and on the video did not appear.

Poshkus, A., & Parker, J. (1970). Studies on nitroaniline–sulfuric acid compositions: Aphrogenic pyrostats. Journal Of Applied Polymer Science, 14(8), 2049-2064. doi:10.1002/app.1970.070140813

Probably this is one of our most useful web page, because on this web page we found mostly all the important information in relation with P-nitroaniline and sulfuric compositions, so here we found all the dangerous information about the gases, and the toxic repercussion on our organism. By sing this web page we learned how to be prepared to face the experiment. Really this web page is mostly perfect, because by the use of some diagrams and theory, it explained everything very good to us.

Poshkus, A. and Parker, J. (1970). Studies on nitroaniline–sulfuric acid compositions: Aphrogenic pyrostats. Journal of Applied Polymer Science, 14(8), pp.2049-2064.

On this web page is very well explained how to do the experiment, because here, there are all the steps, one behind the other, without doing nothing wrongly. Also on this web page says that the gases produced by the explosion are unknown. Even people who works in the NASA do not know how dangerous those gases because they don´t know what gases are produced. W really think that this web page is a very good source, because we have the experiment explained in detail