Chemistry+Applications+Essay+6

Chemistry Applications Essay



__Chemistry of the Sinkhole __

Sinkholes... some small, large, or extreme. Houses are sucked up by sinkholes, city blocks annihilated, but how? People are often fascinated by sinkholes, but often ask themselves how they did they ‘come from.’ Sinkholes are formed in various ways, but the most frequent way is the chemistry way.

Sinkholes are made or created because of voids in the ground. These voids or caverns are made through the rainwater and limestone, typically. When the rain water and limestone meet and do their chemistry work, a small gap is left behind. But overtime, as more gaps are formed, a large cavern is formed. So whatever is above this cavern will eventually collapse in since there is no foundation to support it. Other types of sinkholes can be formed because of weak sewer pipes, abandoned mines, or taking too much water out of the ground below. Each of these is also common. If part of a sewer pipe is weak, the weight above it could crush the pipe, causing a cave in, same said for abandoned mines. If too much water is taken from the ground, a man-made gap could be formed causing a sinkhole. But lets move onto the chemistry of sinkholes, the good stuff.

So how is chemistry related to sinkholes? Well, all you need is just rain and limestone underground. Lets start off with rain, it is naturally acidic because of the combination of hydrogen gas and carbonate. The formula of the formation of rainwater is 2CO 3 -2 (aq) + H 2 + (g) → 2HCO 3 -  (aq). This formula shows that the rainwater is acidic in nature due to the combination of the natural elements in the air. Now that acidic rain falls and sinks into the ground. The water could possibly become more acidic from various chemicals in the ground. As the rainwater seeps through the ground, it comes across the limestone. Now the limestone and acidic water gets mixed up. Limestone is CaCO 3 , so the chemical formula of two would be CaCO 3 <span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> + H <span style="font-family: 'Times New Roman',serif; font-size: 7.5pt;">2 <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">CO <span style="font-family: 'Times New Roman',serif; font-size: 7.5pt;">3 <span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> → Ca <span style="font-family: 'Times New Roman',serif; font-size: 7.5pt;">2+ <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">(aq) + CO <span style="font-family: 'Times New Roman',serif; font-size: 7.5pt;">3 <span style="font-family: 'Times New Roman',serif; font-size: 7.5pt;">-2 <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">(aq) + H <span style="font-family: 'Times New Roman',serif; font-size: 7.5pt;">2 <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">O(l) the calcium is being dissolved by the acidic rainwater. The reason the limestone can dissolve so easily is because it has a small solubility-product constant. Since the rainwater made the solid limestone a liquid, there is a space that is created, because a solid takes up more space than liquid. However, this is just a few drops we are considering, if a large amount of rain falls, then large amounts of space is going to be created! That gives you those nice multibillion dollar destruction that everyone loves so much!

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">The chemistry of sinkholes is no mystery. The chemistry behind it all is known. Such knowledge has been put to great use. One such use is that infrastructure must not be located on top of limestone... imagine a skyscraper collapsing in!

__<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Citation Page __ <span style="background-color: white; font-family: 'Times New Roman',serif; font-size: 12pt;">KP, Chris. "A Sinkhole Lot Of Chemistry." //The Science of Stuff//. Chris KP, 23 June 2010. Web. 04 Jan. 2013.

<span style="background-color: white; font-family: 'Times New Roman',serif; font-size: 12pt;">Nelson, Stephen A., Prof. "Subsidence: Dissolution & Human Related Causes." //Tulane//. Tulane University, 14 Nov. 2011. Web. 3 Jan. 2013. < <span style="color: #1155cc; font-family: 'Times New Roman',serif; font-size: 12pt;">[] <span style="background-color: white; font-family: 'Times New Roman',serif; font-size: 12pt;">>.