OOL3 - Lethal Seas Worksheet PDF

Preview

Summary

Mandatory assignment ...

Description

OOL#3 – Lethal Seas

Name: Alaina Wiggins After watching the documentary, answer the following questions about Lethal Seas and upload to the appropriate dropbox on Canvas. Provide your answers to each question in red text and use appropriate super/subscripts for chemical equations.

1) What happened to the production of pacific oyster larvae off the coast of the pacific northwest (US coast) starting in 2007? They started dying and the populations drastically decreased due to the increasing acidity levels in the ocean water they were extracting. 2) Describe the shell structure of a normal baby oyster observed under a microscope compared to the shell structures observed in 2007 from baby oysters that did not develop properly. A normal baby oyster shell was already developing a shell very young (1 day old), it looked healthy and symmetrical. Compared to the shells of the baby oysters from 2007, their shells were underdeveloped, “deformed and pitted”.

3) What is pH? (In words, not equations). pH is a measure of the hydrogen ion level in the water (in this case). The higher the hydrogen ion concentration, the lower the pH, and lower hydrogen ion concentration means higher pH. Also, pH is the level of acidity in the water. The lower the pH, the higher the acidity.

4) In order for the baby oysters to develop properly it was necessary to add soda ash. This procedure allowed the baby oysters to develop sufficiently to be reintroduced into the bay, however it is very expensive. What is the chemical composition of Soda Ash? And why not use Baking Soda instead? Na2CO3. Baking Soda, on the other hand is NaHCO3 which is different so it would not do the same job. 5) Water sampling around the world over the last forty years has revealed that the average ocean acidity has increased approximately five percent each decade. The increased acidity has been linked with the increase in atmospheric levels of what gas? Carbon Dioxide - CO2 6) Burning gasoline (primarily C8H18) to power car engines is an example of combustion of a hydrocarbon. What are the products and balanced coefficients for the combustion of octane? 2C8H18 + 25O2 →16CO2 + 18H2O

7) Write the chemical equation for the reaction of carbon dioxide and water to form carbonic acid (H2CO3). H2O(l) + CO2(aq)  H2CO3(aq)

8) Carbonic acid, H2CO3 dissociates in water to release H+ ions. What is the balanced equation? H2O(l) + CO2(aq)  H2CO3 (aq)

9) The shells of sea creatures such as oysters are primarily made of calcium carbonate. Calcium carbonate forms by the reaction of calcium ion with carbonate ion. Write the equation for the reaction of calcium ion and carbonate ion to form calcium carbonate. Ca +CO3  CaCO3

10) Ocean water generally contains a high concentration of _____________ ion, but relatively a much lower concentration of carbonate ion. Increased acidity can further _____________ the availability of carbonate ion to form shells due to the following reaction: Calcium, Lower

11) Why might our friends in biology be concerned that increasing acidity in the ocean might disrupt ocean ecosystems? The increasing acidity in our oceans, if effecting the growth, health and population of the base food chain species in the ecosystem. This could lead to mass die offs of sections of the food chain, ultimately effecting humans and our food source....