Ocean Acidification SDI: solubility of co2 in different temperatures

Ocean Acidification SDI: Solubility of CO2 in different temperatures

Aim: To observe the solubility of CO2 in different temperatures

Hypothesis: We hypothesise that in cold water the level of co2 absorption will be greater than warm water which will mean the air space in the cylinder will be less compared to warm water.

Independent: Type of water.

Dependant: room temperature, amount of water, type, size and amount of tablet, amount of water in the basin.

Materials:
250ml graduated cylinder
Funnel
Petri Dish
Transparent basin
Stand and Clamp
Cold Water
Warm Water
Alka Seltzer Tablets

Method:
1. Fill the basin half full with type of water. Place the stand beside the basin
2. Fill the graduated cylinder to the brim with the selected type of water and place it carefully upside down in the basin. Cover the mouth of the cylinder with a Petri Dish so that no water spills out of the cylinder when immersing it in the basin.
3. Invert the cylinder and immerse in the basin.
4. Remove the Petri dish after the mouth of the cylinder is underwater.
5. Secure the cylinder with the clamp to the stand and place the funnel in the mouth of the cylinder taking care that there is minimal space between the funnel and the opening of the cylinder.
6. Place an alka seltzer table under the funnel.
7. Repeat the method

Results: TABLE OF RESULTS

Introduction: The increase in levels of Carbon dioxide released by humans in the atmosphere is causing great harm to the world’s oceans as 30-40% of this CO2 is being absorbed by oceans, rivers and lakes making them more acidic than they have been for tens of millions of years. When carbon dioxide (CO2) is dissolved in water (H2O), carbonic acid is formed (H2CO3). Increasing levels of carbonic acid interferes with the formation of calcium carbonate (CaCO3) which is also a major component of constructing shells for many important organisms. If their shells are deformed or thinner the organisms may be unable to function properly. But how does the temperature affect the solubility CO2 of in water? This experiment was to observe how warm, cold and distilled water would affect the solubility of CO2 in water using alka seltzer tablets as the source of CO2

Discussion:
Like we predicted, the cold water absorbed more of the carbon dioxide released from the bubbles set free by the Alka-Seltzer tablet than the warm water. The solubility of gases decreased with increasing temperature, so the air space inside the cylinder when cold water was used was less compared to warm water. The cold water took up more CO2 and less escaped into the air. The volume of the air space formed in the graduated cylinder is equal to the volume of CO2, which cannot be dissolved in water anymore. Observations showed that the initial gas freed from the tablet was first dissolved in the water and when the water was fully saturated with gas, the gas continued to escape into the air displacing water inside the cylinder forming the air space. With colder waters absorbing more CO2, this means that in the world’s oceans, places like the northern Atlantic and the southern oceans have the most CO2 in them because they are colder. The results also showed that normal, cool, distilled water had similar affects to cold tap water meaning the water absorbed more of the CO2 than the warm water. There were some elements of the experiment that could have been improved or altered to gain better or different results. Instead of boiling the water to get warm water, tap water could be used. To further enhance this experiment, full strength sea water or other different salinities could be tested to compare the results. Another aspect that could have been tested was to use 2 tablets, one after another with the same temperature of water. Also to gather more accurate results, more than one trial could have been tested.

Conclusion:
This investigation has concluded that cold water absorbs more CO2 than warm water. This means that colder parts of the world’s oceans such as the polar seas, are more affected in the process of CO2 released in the atmosphere, by humans more than the warmer parts. Shell construction for marine organisms in these places are harder due to the high absorption rates of CO2 resulting in high acidity levels.