What is the safety rule that keeps ocean from being poisoned?

Death in the Water: How Plastic Is Poisoning Our Oceans

Liz Greene February 17, 2017

We live in a society obsessed with convenience, and that obsession has made plastic king. Though humankind has greatly benefited from plastic, the environmental costs of this reigning polymer may bring about our downfall. Traveling from land to sea in the wind or through waterways, plastic pollution is causing extensive damage to our marine life and giving life to one of the greatest ecological disasters of our times.

Plastic has been collecting in the marine environment since plastic production began in the 1950s — in fact, each square mile of the ocean contains more than 46,000 pieces of floating plastic. Eight million metric tons of plastics make their way into the ocean each year, hitching a ride on the currents and reaching the furthest corners of our seas — even turning up in the Antarctic wilderness. Simply put, the world’s oceans are becoming a toxic soup of plastic and other debris, and all life is being negatively affected.

Unfortunately, plastic doesn’t biodegrade — though it does eventually photodegrade (i.e., break down into smaller fragments by exposure to the sun). Photodegradation of plastic continues to the molecular level, yet photodegraded plastic remains a polymer. No matter how minute the pieces, they will always be plastic. Unlike naturally based paper or glass, they are not absorbed into or changed by natural processes — plastic never truly goes away.

Explanation:

This is a really good article I found, hope it helps

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"