Week 8 Application exercise

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Qn. The concerns of acid rain vary across the globe. What are the issues in Canada? Does the acid deposition occur outside the borders of Canada?

Ans. In Canada, acid rain has depleted calcium levels in lakes. This change in calcium concentrations has caused a shift in th ecological balance. Faced with this selection pressure, a species of plankton which requires less calcium to thrive than a competing species of plankton to gain a survival advantage and thrive. This plankton is thick and jelly like, which means that pipes used to extract water from the lake for drinking purposes get clogged more easily. Also the ecosystem may be further upset.

As for the source of said acid rain, “Between 50% and 70% of Canada’s acid rain comes from the United States, while only 2-10% of America’s pollution in this area comes from Canada.”

 

Sources:

http://www.citylab.com/weather/2014/11/acid-rain-has-turned-canadian-lakes-into-a-kind-of-jelly/382922/

http://www.nature.com/news/2005/050810/full/news050808-10.html

Feedback on the course

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Hi Prof Felipe,

Hope you can see this haha.

Well, we mostly think the TBL format for this course is good because some of the chemical concepts were learnt by those of us who took chemistry at A levels and we can help those who didn’t learn it before during the tRA part.

However, we understand that the lecture theatre setting makes it easy for some students to blatantly refer to the notes on their computers during iRA. Maybe the next time you run this course you can split the class into two sessions, as a smaller class will take less time to complete the whole session, and hold the lessons in the new learning hub classrooms which are more conducive to team discussions.

Homework

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IMG_7647

 

Qn 1: The atmosphere retains much of the energy radiated by the surface. This is known as the greenhouse effect.

Qn 2: No, it is not justified. It does not mean that when during winter, there is snow and it is cold, the earth is getting cooler. It is a difference between weather and climate.

Qn 3: By using the specific wavelength that triggers the rotation of water of water molecules, the microwaves would be be absorbed by clouds since clouds are primarily composed of water. As a result, the microwaves would not be able to pass though clouds and planes could evade detection by flying through clouds. Also, water molecules in the atmosphere would scatter the microwaves making it less effective.

Qn 4: In the short run, air quality will pose the most serious problem since most of the effects of air pollution are immediate, such as asthma and pneumonia. Global warming is more serious in the long run as the effects take several decades to manifest. However, its effects such as rising sea levels, are catastrophic and should be taken seriously. Ozone depletion is the least significant since its effects are confined to less populated areas and the ozone hole is recovering.

 

Minutes log 1

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5/1/2015

Our group discussed about the possible topics we could research on, based on the topic given to us – acid and bases. Each of us took turns to come up with some secondary research on the impact of acid/bases on our society. We narrowed down to three broad ideas:

Idea 1: acids are found in things we consume everyday. some of these acid reactions are beneficial to us, while others have led to problems in society. some are true, while some are myths.

Elaboration: for example, citric acid is largely beneficial as it ensures many of us meet our recommended daily intake of vitamin c, it also acts as a preservative and buffer in much of the processed food we consume, keeping it fresh for longer.

however, a lot of blame has been placed on the acid in soft drinks for causing a lot of health problems in society. firstly, and most obviously, acid from soda causes tooth decay. secondly, acid from soda has been thought to cause osteoporosis as well, but we will show that this is largely false

Idea 2: lets talk about lemon. http://www.vitalitylink.com/article-holistic-health-2055-lemon-juice-acidic-alkaline-body-water

Outside the body, lemon juice is acidic (pH is below 7). This is a non-issue. Everyone knows this. It’s a citrus fruit.

Inside the body however, when lemon juice has been fully metabolized and its minerals are dissociated in the bloodstream, its effect is alkalizing and therefore raises the pH of the body (pH above 7 is alkaline).

it is important for body tissue to be alkaline rather than acidic: in long-term acidic environments, normal cell structure and function are damaged. The exception to this is the stomach, where the hydrochloric acid secreted there is intended to aid in cellular digestion of food.

Idea 3: Importance of acid and bases in agriculture

The acid-base reaction is very important for farmers when keeping their soil pH at a suitable level for their farming activities to occur. Sulfuric acid, one of the most important industrial chemicals, is used to manufacture fertilizers for agriculture.

Below pH 4, the H+ ions start to damage plant root cell membranes

–> Buffering agents are extremely important

–> Monopotassium phosphate, MKP is used as a fertilizer and fungicide –> Ammonium (NH4+) fertilizers react in the soil in a process called nitrification to form nitrate (NO3−), and in the process release H+ ions.

Finally, after some discussion, we decided to amalgamate ideas 1 and 3 and set our project scope to be that.