The contact process is used to make sulfuric acid. The simpler type of the contact process is the sulfur-burning plant. This plant uses sulfur as a raw material. Sulfur is burned and becomes sulfur dioxide. Then, it is cooled and oxidized. One might notice that oxidation kind of sounds like oxygen. This is because oxygen has the highest electronegativity (atoms’ ability to share electrons, called a covalent bond) and draws the density of the electron toward the oxygen and farther away from the other substance. Oxidation is losing electrons, so when it occurs, the element becomes positively charged. And, sulfur dioxide then becomes sulfur trioxide.
The other type of the contact process makes sulfur dioxide from materials that have sulfur, such as pyrite. The sulfur dioxide from the material (is a gas, in this case) is cooled, so that impurities can be removed. When it is condensed, aspects of the water vapor are removed to dilute (weaken) the acid product after water vapor is removed. The sulfur dioxide is dried with concentrated sulfuric acid and is then cold, and so must be heated.
The contact process is used for things such as fertilizer, batteries and explosives.
Peregrine Phillips developed the contact process during the 1830s. He was from the United Kingdom.
Basilius Vantelius, in the 15th century, made sulfuric acid by burning sulfur with potassium nitrate. In the 17th century, saltpeter and sodium nitrate were used to speed up the process of burning sulfur. In the 18th century, John Roebuck developed the Lead Chamber Process that used a chamber made from lead (before that, glass had been used) and was able to make a lot of sulfuric acid. This was important because it sped up the process of making sulfuric acid and was able to produce more of it.
Since energy is released during this process, a lower temperature should be needed. But, the lower the temperature is, the slower the reaction. Also, to get as much sulfuric acid as possible, a high atmospheric pressure is needed.
Since a pretty high temperature is an ideal condition for the contact process, it often cannot be used due to the fact that it is pretty expensive to get the temperature so high. And, a high atmospheric pressure is also pretty expensive, and so is also often not used. The expense makes it harder for the contact process to occur in ideal conditions.
Vaageesha Das is a 10th grader at Morgantown High School. Today’s information comes from: https://www.britannica.com/technology/contact-process; https://socratic.org/questions/what-does-it-mean-if-something-is-oxidized; https://www.angelo.edu/faculty/kboudrea/periodic/trends_electronegativity.htm; http://www.docbrown.info/page01/ExIndChem/ExIndChemb.htm; https://www.oxforddnb.com/view/10.1093/ref:odnb/9780198614128.001.0001/odnb9780198614128-e-37853; https://contactprocess.wordpress.com/history/; https://www.chemguide.co.uk/physical/equilibria/contact.html.
