Use of Acids and Bases on the Boat

A few days into Leg 6 of the Volvo Ocean Race, the crew members have been rearranging the items on the ship to best suit the situation. It's been a hassle having to stack all the excess sails, equipment, freeze-dried food supplies and clothing, move them to the bow (front), back to the stern (rear) again and again. 

I had hauled around several large, fluid-filled containers before I stopped to examine their contents. About half of them were common cleaning agents for the boat. Most were either acidic or basic in nature, as acids are corrosive and bases, once they are far up the pH scale, are corrosive as well. For example, phosphoric acid was used to remove rust from iron and steel surfaces by converting iron oxide to ferric (iron III) phosphate: Fe₂ O₃ + 2H₃PO₄ → 2FePO₄ + 3H₂O. The residue material can be scrubbed off to reveal a clean surface, or kept to provide further protection from corrosion. Sodium hydroxide, also known as caustic soda, is a base that, when added to water, can be used to clean machinery equipment and storage tanks. The chemical is effective at removing most viruses, bacteria, and other toxins in the water. Sodium hydroxide is used to clean the boat because it costs little, and is easily removed and disposed of after use.

The remaining half of the containers were lubricating fluids used for the Camper’s internal combustion engines. In the engine, lubricant oils and cools the power transmission components to reduce friction and prevent overheating. It removes the impurities from the engine fluids, neutralizes potentially explosive byproducts of combustion, and prevents rust and other forms of corrosion.  A variety of base oils and additives are also included in the lubricants to tailor them to specific applications (e.g. can operate in wet conditions, resist thermal decomposition). It is important that the right lubricating fluid is chosen, as there are many additional expenses if the fluid needs to be replaced. Waiting for the old fluid to drain out and for the new fluid to be added can waste precious time. Using the wrong fluid would also mean increased corrosion of the engine.

Acids, on the other hand, are used in cooling fluids and antifreeze in order to maintain machinery. Antifreeze is a liquid solution that lowers the freezing point of whatever mixture it is added in, acting as a de-icing agent. Properties of an ideal antifreeze include excellent solubility, a high boiling point (to handle high temperatures inside the engine), excellent heat transfer properties, moderate viscosity, and low cost. Ethylene glycol is the most commonly used antifreeze because of its  low instability and water solubility. Most antifreeze liquids also include chemicals that prevent corrosion, to protect the metal surfaces inside the engine. However, once the antifreeze begins to decompose and breakdown, or the substances that prevent corrosion are depleted, the fluids should be replaced. 

References

Reignbough Chase. Iron (III) Phosphate. 2007. Photograph. Ford Muscle Forums. Web. 6 May 2012. <http://i285.photobucket.com/albums/ll66/Reignbough_Chase/dswofgr.jpg>.

Anglin, Donald. "Engine Lubrication." Access Science. McGraw Hill Companies, 2008. Web. 25 April 2012. <http://www.accessscience.com/content.aspx?searchStr=engine lubricant&id=233400>.

Danny Catucci. Engine Flush. 2010. Graphic. Redwood General Tire Store, Redwood City. Web. 5 May 2012. <http://www.redwoodgeneral.com/img/photos/engine-flush.gif>.

Butterfield, Sharon. "How Does Antifreeze Work." Wise Geek. Conjecture Corporation, n.d. Web. 12 April 2012. <http://www.wisegeek.com/how-does-antifreeze-work.htm>.

George, Kathleen. "Antifreeze Mixture." Access Science. McGraw Hill Companies, 2008. Web. 2 May 2012. <http://www.accessscience.com/content/Antifreeze mixture/040400>.

Barbara Terry. Cooling System. 2008. Graphic. Family Car Parts. Web. 10 May 2012. <http://www.familycar.com/Classroom/Images/Cooling-System.gif>.

Ph Levels in the Oceans

Today, as we were travelling along the Brazilian coast, we were visited by a pod of playful dolphins.  They reminded me of the delicacy of Earth’s ocean biome, and how small changes can result in large consequences.

Time for a brief chemistry lesson! When carbon dioxide from the atmosphere dissolves in the ocean, it forms carbonic acid. However, it quickly breaks down into bicarbonate (HCO₃) and hydrogen ions (H+).

H₂O + CO₂ → HCO₃ + H

Since acidity is the measure of hydrogen ions in a fluid, as the number of ions increases, the acidity of the oceans rises as well.

The pH levels of the oceans are regulated by a process called “buffering”, where hydrogen atoms react with calcium carbonate to produce carbon dioxide and water. This is the opposite of the process that previously occurred:

HCO₃ + H → H₂O + CO₂

However, there must be enough calcium carbonate in the oceans to increase carbon dioxide levels, and currently, the ocean’s buffering system is not effective enough to counter the rapid increase in the water’s acidity.

 The Earth’s oceans are normally slightly basic, but with an increase in greenhouse gases, the seawater will likely slide down the Ph scale. Since the Ph scale’s intervals are by powers of 10 (each level is to the 10^th power more acidic then the level below), this represents a drastic increase in the water’s acidity.

Dolphins are considered a symbol of protection in many cultures around the world. The health of these dolphins relies on the health of the ocean’s ecosystems, and hopefully we can all make an effort to ensure that these lovely creatures survive.

References

 Adam-Carr, Christine, Douglas Fraser, et al. Science Perspectives 10. Toronto: Nelson Education Ltd, 2010. Print.

Findlay, Helen. "Ocean Acidification." Catlin Arctic Survey Blog. Catlin Arctic Survey, 12 Apr 2011. Web. 21 April 2012. <http://www.catlinarcticsurvey.com/2011/04/12/ocean-acidification/>.

Gerad Bandos. Ph Scale. 2007. Graphic. Chemical Education Digital Library. Web. 6 May 2012. <http://chemteacher.chemeddl.org/services/chemteacher/images/stories/pH_Scale.jpg>.

Kim Martineau. Ocean Chemistry. 2009. Photograph. Ocean Acidification. Web. 27 April 2012. <http://theotherco2problem.files.wordpress.com/2009/11/ocean-chemistry.gif>.