Chemistry Ch. 9 Essays

Topics include: Qualitative analysis, Waste and supply H2O treatment, Harmful Natural Pollutants, and Harmful H2O pollutants created by human activities.

Qualitative Analysis:

There are two general form of analysis; Quantitative analysis and Qualitative analysis. Quantitative

analysis determines the quantity of a substance as Qualitative analysis identifies its quality. Qualitative

analysis, which can be considered a branch of chemistry, is limited to the identification of a singular or

group of elements, ions, or compounds in a sample. It is nearly always the qualitative analysis which is

performed prior to the quantitative analysis (but can be performed together) when in need of

performing an experiment, test, etc….

The techniques or methods employed for such identification vary in complexity and are dependent on

the nature and/or purpose of the sample being identified. It is also customary to divide the identification

procedures into two classes: qualitative organic analysis and qualitative inorganic analysis. Qualitative

organic analysis is the more complex of the two. It is like such since it is limited to only using

instrumental methods of identification such as electrophoresis (the movement of charged particles,

caused by an electric field, through a gel or a liquid). It is as well as the least common or applicable of

the two due to the millions of possible organic compounds with which only a few thousands have been

identified.

The inorganic qualitative analysis is the most applicable qualitative analysis because it applies to non-

carbon chemistry which includes metals, metalloids, hydrogen ions etc… Thus it is used the majority of

the time due to the accessibility of the substances as well as the techniques used. The techniques

employed in inorganic qualitative analysis are not limited to instrumental methods such as organic

qualitative analysis. It uses both, instrumental and/or manual methods. In certain cases it is necessary to

only identify certain elements, ions or compounds of the sample, for which specialized tests are

available. These specific test include: flame test, precipitation, bead test, manual titration, spot test, and

many more.

One of the most common of these is the flame test. A qualitative analysis used to detect and identify

only certain metal ion(s) in a sample. This is possible due to the particular colour of flame the specific

sample produces when reacting with a flame. Each colour has been identified as a particular ion which is

due to the unique arrangement of electrons within the sample’s atoms. (Ex. Lithium produces a crimson

red, Sodium a yellow and Calcium a light orange-red) This test can be performed through the use of a

Bunsen burner and a clean wire loop of either an alloy of nickel and chromium or of simply platinum.

The testing slightly differs if whether the sample is a solution or a solid. If a solution the wire is dipped

into it and then held in direct contact with the flame. If a solid the wire is usually moistened with

Hydrochloric Acid (HCL) or Nitric Acid (HNO3) to aid the solid to stick to the wire, which is then placed in

the flame. What produces the colour of the flame is that the electrons of the sample absorb energy from

the flame and then re-emit a certain amount of it as visible light. This identification method is one of the

most common tests for it is effective. The flame tests are very sensitive which is also why the majority of

the samples are tiny. The small size contributes to the reduction of the cost since the wire alloys are very

expensive. Thus the smaller the samples the less expensive.

If focusing on determining an unknown ion, element or compound in a solution Precipitation reactions is

another useful procedure. This procedure begins by the addition of a known reactant to the solution and

observing is a precipitate will form. If the reaction produces a precipitate, one must be able to refer the

solubility guidelines and deduce which ion(s) was present to cause such reaction. Every time a

precipitate is produced the removal of the particular ion(s) in the solution occurs. Thus, the process can

be repeated multiple times to determine the remaining ion(s) by adding a different reactant, but only

after the precipitate is successively filtered which can be used in a flame test as verification.

Those are two examples of the testing techniques of the unique branch of chemistry known as

Qualitative analysis. This analysis is the identification of what is present within the sample, not the how

much. It deals with determining the identities of the unknown ions, elements, and/or compounds in a

substance. The techniques of identification will depend on whether one is in need of identifying an

organic substance or an inorganic substance, as well as the nature and purpose of the sample. Thus the

methods will vary in complexity. It will also depend on the budget for different test have very different

costs; mainly between instrumental methods and manual methods.

Desalination:

Earth is covered in 72 percent water, but the majority of it is sea water. Thus it is too salty and harmful

to consume. Given that salt unbalances the natural flow of substances in and out of cells. The salt causes

the water present in the cell to flow out, resulting in dehydration. The technique used to remove the salt

from the seawater and obtain fresh water is Desalination.

The varying levels of salinity (measured in ppm) in water affects the difficulty and expense of the

treatment. Given that the more concentrated saline the body of water is, the more energy it takes to

desalinate it. Hence, water that is of 1, 000 ppm in terms of salinity is usually considered as fresh water

and safe to use for household and agricultural purposes, and consume. Any higher than this standard,

will be desalinated.

To do so, there are varying methods at which our society uses to desalinate seawater. These processes

include: reverse osmosis, forward osmosis, electrodialysis, thermal distillation, multistage flash

distillation and multiple-effect distillation. Out of all these reverse osmosis is the most commonly

applied, and multistage flash distillation is the one which produces the largest quantity of fresh water.

Reverse osmosis is the most common for it is currently the most energy efficient process. It is the

process of using an extreme amount of pressure to force the water through a semi-permeable

membrane. A membrane which prevents larger solutes to pass through, hence the salt remains on the

other side of the membrane as the liquid passes through. This results in a low concentrated solution

which can be further treated to become potable water. The two major setbacks are that after the

process is complete, the water’s impurities such as the salt is returned to the ocean. Even though they

are returned to the ocean without added chemicals it will, in future, make it harder to desalinate. It will

be harder to desalinate seeing that the seawater will have a higher concentration of salt. It will also

affect the ocean’s ecosystems and its wildlife. The second setback is that the semi-permeable

membranes are easily clogged up since they gather too much bacteria. To treat this, chlorine is used as a

disinfectant, but chlorine is known to deteriorate the membranes. Thus it is not cost efficient.

Multistage flash distillation plants are constructed near or alongside power plants since they are built to

use their wasted heat. These plants need these large quantities of heat since heat is a key factor in the

process. Multistage flash distillation is the process in which the product of the heated water is again

reheated numerous times, but each time is at a lower pressure than the previous one. Allowing for this

process to require less quantities of energy than reverse osmosis. Sadly, this method has its own

disadvantages. The main ones are that the maintenance costs are painstakingly high. It also requires a

much larger intake of seawater than reverse osmosis. Despite that, Saudi Arabia has quite a few of

multistage flash distillation plants which account for 85 percent of all desalinated water.

Desalination, as a technique of its own, has its own overall negatives. It is known to require a large

expanse of energy to start up and power the desalination plants. Consequently, this also results in it

being extremely expensive since the majority of its current power sources are derived from the burning

of fossil fuels. Thus it is not cost efficient nor is it always environmentally friendly.

The location of Distillation plants are primarily in developed countries which have more than enough

money and resources to fund such operations. That is why the majority of these plants are situated in

the Middle East which is located near to distill ocean water. Although, if technology continues to evolve

at such a rapid rate it would hopefully result in newer and better techniques or even solutions of

desalination. The procedure of removing salt from water which could provide numerous countries that

are facing drought, overpopulation and/or other difficult times, a new fresh water source.

Harmful Substances from Natural sources:

One always hears about the need to reduce pollution, and that humans are the main source of pollution.

Yes, humans are the largest source of pollution, but it is not the only source. Many harmful substances

come from nature as well. These pollutants are known a natural pollutants, and have been present ever

since the formation of Earth, which is approximately 4.54 billion years ago.

They are natural pollutants because they are created by substances of natural origins such as sea salt

particles, volcanoes, dust storms, forest fibres, photochemically formed ozone, amongst numerous

others. When generally discussing natural pollutants, one is mainly discussing of air pollution since this is

where the majority of natural pollutants can be presently found. Theses natural airborne pollutants

stem from many different sources, but are usually in result of a combustion reaction such as forest fires.

A natural pollutant which is often mistaken to be solely perceived as an airborne pollutant caused by

industries is Sulfur dioxide (SO2); but there are more natural SO2 sources than man-whilst ones. Certain

examples include volcano eruptions, biological decay and forest fires. SO2 has been recognised as an air

pollutant since discovering its role in the forming of winter-time smog. There also studies which have

indicated that this pollutant causes irritation, coughing, nerve stimulation within the lining of throat and

nose, as well as causing the body’s airways to narrow. Its impact on the environment is that it is a potent

reagent of acid rain – which damages the environment by changing the makeup of the soil and leaching

into surface water sources. A long exposure will quickly destroy the ecosystems.

Another substance which is often viewed as caused by mainly humans are nitrogen oxides. Natural

sources of these oxides include oceans, biological decay, lightning strikes and volcanoes. It was

estimated in 1983, by the United Nations Environment Programme, that 80 million to 288 million tonnes

of SO2 came from natural sources. As for nitrogen oxides, it was estimated between 20 million and 90

million tonnes.

Other natural pollutants include VOCs (Volatile Organic Compounds). They consist of a variety of

individual organic substances such as hydrocarbons. Due to their high volatility they are able to exist as

vapour present in the atmosphere. A VOC which we hear quite often is Methane. This gas impacts the

environment through its principal role in global warming and the production of ozone within the

troposphere (lowest layer of the atmosphere).

There are many more examples of natural pollutants such as Arsenic, Fluoride 17th, and Calcium ions.

They are many for they are pollutants created from natural origins thus it is not man-made and have

almost abundant sources. They have contributed to pollution ever since the Earth was formed, but they

are presently limited to a small percentage of Earth’s present pollution. They are mainly seen as a small

contributor to airborne pollution for the majority are due to a combustion reaction. Despite the fact

they are a small contributor to pollution, it does not mean they are not as harmful nor as important.

Natural pollutants such as nitrogen oxides, VOCs, SO2 and numerous more can cause major damages to

our health and the Earth’s environment.

Harmful H2O pollutants due to humane activities:

Our Earth is 4.54 billion years old. It has evolved to the point where it can sustain life, and of course

there are natural disasters, natural pollutants etc… that continuously damage the Earth. Consequently

since the last couple centuries there has been one major damaging source; humans. The human race is

damaging the Earth in countless of ways. One of these ways is water (H2O) pollution.

Nearly all human activities such as transportation, farming, industry, garbage disposal, etc… create some

sort of pollution. To categorise the pollutants they are divided into two classes. One being the Point

Source and the second being Non-Point Source. The point source is a pollution source of one specific or

direct location or source such as an industry producing plastics or chemicals. Non-point source is

pollution which does not have a one specific location/source, but is the accumulation of many which has

spread over an area. Some examples could be pesticides and fertilizers.

Major water pollution sources include lead pollution, mercury pollution, nitrate and phosphate

pollution, etc… Lead pollution, if exposed to it, can lead to medical problems such as kidney failure,

nerve damage, and brain disorders. The major source of exposure to lead pollution is through old water

pipes since up till the 1950s communities used lead to construct the water pipes. Humans used lead

since it lasted longer and did not corrode as easily as iron. Another main source of exposure is through

industrial processes such as smelting, the manufacturing and recycling of car batteries, and the

production of plastics. Although all this is airborne exposure, the pollution ends up in the water through

the natural cycle of water (evaporation, condensation, precipitation, etc…).

Water pollution can also be easily caused by plastic bottles. Clear plastic bottles are composed of

polycarbonates (hard and clear plastics). These polycarbonates are comprised of a chemical called

bishphenol (BPA). This chemical when exposed to heat and oxygen can leach into the water within the

bottle. It can also easily leach into the environment if not properly contained in a recycling plant or

landfill. BPA has been tested and is shown to have links with breast cancer and to trigger biological

changes such as the ones caused by estrogen. Luckily Canada was amongst the first to ban the use of

BPA in baby bottles, unfortunately it is still used to make a large variety of things such a kitchen

containers and plates.

These examples should demonstrate that contaminated water acts as well as a pollution source and

catalyst since the pollutants within will come into contact with everything the water does. Hence the

pollution can then leach into the environment (soil, forest, oceans) and damage its resources alongside

destroying the ecosystems. It can also be consumed by humans and other living organisms without

being properly treated resulting in health complications. Likewise it can be used for farming thus

contaminating our food sources. Water pollution is dangerous since its pollutants will contaminate

everything it comes into contact with and its source is uncontrollable.

A primary example of a product of water pollution is acid rain. Motor vehicles, farms, industries, etc…

release tons of carbon dioxide, sulfur dioxide, and nitrogen oxide gases. These airborne, non-metal

oxides dissolve into the rain present in the clouds, producing acid rain. It is a rain which with a high

acidity level can cause a great amount of damage such as the dissolving of various compounds from the

soil and rock. An example is Aluminum. It is abundant in our Earth’s crust and its ions are leached into

the ground and surface water by acid rain. This leaching harms the water’s living organisms such as the

fish who the ions impede the extraction of oxygen from their gills.

These are few examples pollution sources and the products out of countless, and they demonstrate why

there is a crucial need for the human race to start taking responsibility and stop these harmful pollutants

from continuing to be used and produced. These are pollutants which we have created and it is affecting

us through damaging the Earth which we live on and depend on, particularly through water pollution

since the Earth is 72 percent H2O.

There are thousands of ways to contribute to help reduce pollution, but here are three to begin with.

The first is to stop being as dependant on cars. This will contribute to the reduction of airborne pollution

which will also reduce water pollution and its products such as acid rain. The second is to boycott certain

products which contain these harmful pollutants, for example only buy local foods. The third is

conservation; conserve electricity, water, etc… This will decrease the need for certain pollutants to be

produced as well them being used.

H2O waste and H2O supply treatment:

The majority of towns and cities have an underground system of pipes and sewers which transports

wastewater as well as supply water to the treatment facilities, but how do we clean these polluted

waters? Why do we clean them? Wastewater is the water which has been used, polluted and discharged

by homes, businesses, industries, and in certain cities rainwater water is included. As supply water

originates from a surface water source (lake, rivers) or underground water source (wells), and has been

contaminated through natural and man-made pollution.

Contaminated water, specifically wastewater, is a solution of roughly 99.9 percent water (H2O) by

weight, and 0.1 percent of dissolved and non-dissolved, suspended solids. This solution is transported by

the pipes and sewage systems to the treatment plants. Facilities where the goal is to remove chemicals,

harmful bacteria, nutrients, solids and other unwanted substances from the water. The goal of purifying

the water to be useful in the society or released into the environment.

The need of consuming water dates back to the existence of living organisms. Every creature has this

need to survive. The need for clean potable water roughly dates back to the Greeks and Romans who

were most likely the first to be intellectually capable as well as having the right resources available. To

them.

The concept of sewage systems also date back as the Minoan civilization; as well as the civilization of

Crete and the Romans. All three had constructed an early model of a three-way and underground

channels and pumps system, to serve as their sewage system. One system would only be used for clean

and drinking water, as the second for human waste and the third for drainage (rain). The appearance of

modern sewage system date back to around the 19th century. It began with the expansion of the storm

sewers. They were expanded to accept larger quantities of water as well as to carry wastes to nearby

waterways. The concept of municipal sewage treatment was not adopted until the 20 th century where

the ever-expanding cities pollution showed the government that quality standards were needed to be

put in place. Thus changes were needed to be done to clean untreated water.

The way which we currently maintain those standards is with three treatment stages; Preliminary

(mechanical), Secondary (biological), and Tertiary (advanced). However the step before the treatment

begins is the transportation. The waste or supply water must be securely transported from its source

(sewage tank, lake, river, well, etc…) to the treatment plant. After the transportation stage the

treatment begins. It begins with the primary or mechanical treatment consists of the removal of solids

through trapping and sedimentation, and skimming the surface and removing scum. This removal is

primarily done with filtering the liquid through a coarse screen of metal bars to remove the large

particles and trash. Then endures through the process called flocculation. This process includes the

addition of calcium hydroxide and aluminum sulfate which react to create a sticky residue aluminum

hydroxide precipitate. This precipitate settles slowly and captures the finely suspended particles and

solids. Once reaching it limit of trapping these impurities it sinks to the bottom of the tank ready to be

removed. This stage reduces up to 50-60 percent of suspended solids.

The secondary stage or biological treatment stage differ between supply water and waste water. During

the secondary stage, waste water is treated through the use of natural micro-organisms. They remove

organic matter from the sewage water by feeding on it. They are bacteria which convert the organic

material into CO2, H2O, and nitrogen compounds. As for the supply water is once again filtered, but this

time through a bed of sand and graded gravel.

The third and last stage, also known as the “advanced” stage, is again different for the supply water and

waste water. For the waste water this stage is capable of removing up to 90 percent of the water’s

impurities. This is possible through the addition of chemical precipitation of nitrogen, phosphorous and

organic compounds. As for the supply water, this stage consists of saturation. The water is sprayed into

the air and is saturated with oxygen which contributes the taste and odour, but also the removal of

volatile organic compounds. Even though this stage differs between supply and waste water, there is

one common factor. For both water treatments chlorine may be added as a disinfectant, but due to

environmental and health complications, certain treatment plants do not use it.

These are the three general water treatment stages. There are many other, more precise, techniques

(activated carbon, membrane separation, etc…) which occur alongside or separately to these treatment

stages. Here are few stages which occur after treatment. The first is the standard testing to ensure that

treatment proved to be effective or not. The other is storage. After being treated the water is

sometimes stored in a storage tank for later use. The last is transportation. The water is securely

transported to wherever it is needed

The techniques and the technology used to remove impurities from waste and supply water have greatly

evolved. They have increased in efficiency, precision, and some are less environmentally endangering,

but they have also increased in scale and in cost. It is concerning that the need of purification has

increased on a large scale, but it is a concept which has been present for centuries and one which is

vitally important to our society. If waste and supply water are not properly transported and treated

there would be many consequences such as disease outbreaks, harmful pollution, poisoning, etc… Thus

it is important that each town or city has a good sewage and/or pipe system as well as a functioning

waste and supply water treatment plant.

Bibliography:

Textbook:

Clancy, Christina. McGraw-Hill Ryerson Chemistry 11. Toronto: McGraw-Hill Ryerson, 2010. Print.

Websites:

Aintablian, Xanthe Webb. "Water Desalination." About.com Geography. About.com, n.d. Web.

15 May 2014. <http://geography.about.com/od/waterandice/a/Water-Desalination.htm>.

"Air Pollution." Air Pollutants | Sulphur Dioxide | Nitrogen Dioxide | Ozone. N.p., n.d. Web. 15

May 2014. <http://www.air-quality.org.uk/04.php>.

"Desalination Overview." IDA. N.p., 2014. Web. 15 May 2014. <http://idadesal.org/desalination-

101/desalination-overview/>.

The Editors of Encyclopædia Britannica. "Qualitative Chemical Analysis

(chemistry)." Encyclopedia Britannica Online. Encyclopedia Britannica, 27 July 2012. Web. 06

May 2014. <http://www.britannica.com/EBchecked/topic/486045/qualitative-chemical-

analysis>.

Helmenstine, Anne Marie, Ph.D. "Flame Tests - How to Do a Flame Test for Qualitative

Analysis." About.com Chemistry. About.com, n.d. Web. 06 May 2014.

<http://chemistry.about.com/od/analyticalchemistry/a/flametest.htm>.

Helmenstine, Anne Marie, Ph.D. "Identifying Anions and Cations: An Introduction to

Qualitative Analysis." About.com Chemistry. About.com, 2014. Web. 15 May 2014.

<http://chemistry.about.com/od/lectureclassnotes/a/Qualitative-Analysis.htm>.

Helmenstine, Anne Marie, Ph.D. "Qualitative Analysis - Chemistry Bead Tests." Qualitative

Analysis - Chemistry Bead Tests. About.com, n.d. Web. 06 May 2014.

<http://chemistry.about.com/library/weekly/aa010102a.htm>.

"Introduction to Wastewater Treatment Processes." The World Bank Group. N.p., 2014. Web. 15

May 2014. <http://water.worldbank.org/shw-resource-guide/infrastructure/menu-technical-

options/wastewater-treatment>.

"Natural Pollutant." OECD Glossary of Statistical Terms - Natural Pollutant Definition. N.p.,

n.d. Web. 15 May 2014. <https://stats.oecd.org/glossary/detail.asp?ID=1738>.

"Pollutant Information: Sulphur Dioxide ." National Atmospheric Emissions Inventory. N.p., n.d.

Web. 14 May 2014. <http://naei.defra.gov.uk/overview/pollutants?pollutant_id=8>.

"Pollution." Curiosity.com. Discovery.com, n.d. Web. 15 May 2014.

<http://curiosity.discovery.com/question/what-history-sewage-treatment-systems>.

"Qualitative Analysis Definition | Investopedia." Investopedia. N.p., 2014. Web. 15 May 2014.

<http://www.investopedia.com/terms/q/qualitativeanalysis.asp>.

"Sulfur Dioxide Pollution." Environmental Impact. N.p., n.d. Web. 15 May 2014.

<http://envimpact.org/node/19>.

Summers, Vincent, and Jessica Seminara. "What Is Qualitative Analytical

Chemistry." WiseGeek. Conjecture, 21 Apr. 2014. Web. 06 May 2014.

<http://www.wisegeek.com/what-is-qualitative-analytical-chemistry.htm>.

Summers, Vincent, and Jessica Seminara. "What Is Qualitative Analytical

Chemistry." WiseGeek. Conjecture, 21 Apr. 2014. Web. 15 May 2014.

<http://www.wisegeek.com/what-is-qualitative-analytical-chemistry.htm>.

"Wastewater Treatment." City of Ottawa. N.p., n.d. Web. 15 May 2014.

<http://ottawa.ca/en/residents/water-and-environment/sewers-and-septic-systems/wastewater-

treatment>.

What Is Wintertime Smog? Dir. King's College London. Perf. Environmental Research

Group. YouTube/What Is Wintertime Smog? YouTube, 21 Oct. 2011. Web. 15 May 2014.

<https://www.youtube.com/watch?v=jWTqEgRbcHs>.

NOTES:

Waste and Supply Water treatment:

Books def:

- Most towns and cities have a system of pipes and sewers which transports the water to the waste-water treatment facility which its purpose is to remove solids, chemicals, and dangerous bacteria and other substances from sewage so the water can be released back into the environment

- Procedure: Has 3 main stages after water has passed through screens made from closely spaced metal bars = remove large solids and garbage 1) Primary treatment: occurs in a holding tank where the removal of solids through

sedimentation and by skimming scum of the surface. Calcium hydroxide is also added along with aluminum sulfate which together create a sticky aluminum hydroxide precipitate which settles slowly which removing suspended particles and some bacteria

2) Secondary treatment: the use of natural micro-organisms to feed on organic matter in the sewage water. These bacteria convert the organic material into CO2, H2O, and nitrogen compounds

3) Tertiary treatment: uses chemical precipitation of nitrogen, phosphorus and organic compounds

http://ottawa.ca/en/residents/water-and-environment/sewers-and-septic-systems/wastewater-treatment

Wastewater is water that has been used and discharged by homes, businesses and industries. It is 99.9 percent water by weight, with a very small portion (0.1 percent) of dissolved and suspended solids.

Preliminary:

Coarse screening Fine screening Grit removal

Secondary:

Removal of settleable solids (sludge) and flotable material (scum)

Final:

Naturally occurring bacteria remove dissolved and suspended organic pollutants

Phosphorus is removed through chemical precipitation. Before it is finally returned to the Ottawa River, the treated water is disinfected using sodium hypochlorite, from May 16 to November 15 annually.

http://curiosity.discovery.com/question/what-history-sewage-treatment-systems

http://water.worldbank.org/shw-resource-guide/infrastructure/menu-technical-options/wastewater-treatment

H2O supply treatment:

Books def:

a) Municipal water treatment:- General: Water enters treatment plant from a surface source (lake, river, reservoir etc…) or from

ground water source (well or a spring). During its travel to the storage tower it is filtered, treated with chemicals to remove suspended particles + treated with Chlorine or ozone to kill harmful bacteria. After treatment there is a standard testing to ensure treatment proved to be effective or not.

- Step by step:1) A coarse screen made of metal bars filters out the large particles and trash2) Process called flocculation removes suspended particles (clay, and micro-organisms).

Calcium hydroxide and aluminum sulfate are added and react to produce aluminum hydroxide which is a sticky gel that traps the finely suspended particles; and with its trapped particles it settles at the bottom of the tank ready to be removed.

3) Water is filtered through a bed of graded gravel and sand4) Water is often saturated with oxygen by it being sprayed into the air, which also contributes

to the removal of volatile organic compounds + improves the taste and odour5) Water receives a chlorine treatment to kill bacteria and ammonia is added to ensure that

the chlorine lasts longer in the piping6) Stored in a storage tank and/or is transported to wherever it is needed

Qualitative Analysis:

Book def:

- analysis that identifies elements, ions, or compounds in a sample (indicates how much of a given ion is present in a solution)

- qualitative analysis is limited to being only useful to determine the ions present in a solution- if chemists or scientists are in need to perform Qualitative & Quantitative analysis, they most

commonly perform the Qualitative analysis prior to Quatitative; apart from performing both at the same time

a) flame test: qualitative analysis used to detect+identify CERTAIN METAL ion(s) in a sample.- It uses the colour of the flame which the specific sample produces, to identify the metal ion(s).- They can be performed using Bunsen Burners + clean wire loop of platinum or an alloy of

nickel+chromium. - TESTING: an (aq) solution – wire is dipped into it ; a solid – wire can be moistened with HCL or

Nitric acid to help the solid stick to the wire. - The wire is then put in contact with the flame. - The electrons of the sample absorb energy from the flame = they then re-emit some of the

energy as visible light. - The specific colours are dependent on the arrangement of the electrons within the samples’

atoms. - Flame tests = very sensitive thus the samples are tiny + the fact that the wire alloys are expensive

b) Precipitation Reactions: another procedure used to determine an unknown ion in a solution; it is done by adding a known reactant to the solution and observing if a precipitate forms.

- Then, one must refer to the solubility guidelines to deduce which ion must have been present to cause such reaction.

- Every time a precipitate forms = removal of the specific ions from the solution- Thus, the process can be repeated to determine the remaining ions through the colours

produced when reacting with different reactants; but only after filtering out the precipitate which can be used in a flame test to double check

http://www.investopedia.com/terms/q/qualitativeanalysis.asp

- The use of subjective judgement on non-quantifiable information- Qualitative has the word “quality” in it = the study of quality of something

http://chemistry.about.com/od/lectureclassnotes/a/Qualitative-Analysis.htm

- Used to detect and separate cations and anions in a sample substance- Non-numerical data collection based on attributes

http://www.britannica.com/EBchecked/topic/486045/qualitative-chemical-analysis

http://www.wisegeek.com/what-is-qualitative-analytical-chemistry.htm

- Branch of chemistry in which studies the identification of an element or a group of elements in a sample

- The techniques/methods employed in a qualitative analysis vary in complexity and depend on the nature/purpose of the sample

- In certain cases it is necessary to only identify certain elements of the sample for which specific tests are available – flame test and spot test and bead test,

- Often the solution is a complex mixture and thus to ensure that all elements are identified a systematic analysis is in order = it then customary to divide the methods in 2 groups: qualitative organic analysis and qualitative inorganic analysisa) Organic analysis:

- The more complex of the 2- Identification methods are limited to instrumental methods and include gas-liquid

chromatography and electrophoresisb) Inorganic analysis:

- Applies to mostly non-carbon chemistry including metal, metalloid, hydrogen ions etc….- Most common and testing for these include manual titration, pH testing and flame test- Testing is composed of a couple different test: Preliminary test – dry test, Secondary test –

dissolving in water, Third test – treating successively the solution with a different reagent each time so that the solution breaks down bit by bit into its different constituent (element), After separation each constituent is further examined to confirm its presence, Fourth test – each constituent is then again divided to be separately divided to be analysed to determine the cationic and the anionic constituents

Man-made pollutants:

Book def:

A) Majority of human activities = pollution of water systems: ex. Farming, industry, transportation, garbage disposal, etc…

- Classification of pollutant source: a) Point source: a source of pollution which has only 1 direct/specific locationb) Non-point Source: pollution doesn’t come from 1 source directly, but is the accumulation of

many spread over an area. Ex: pesticides&fertilizers- The cumulative effect on Ontario’s lakes and ground water from small point sources of pollution

= major problem. 2009 = Cosmetic Pesticide Act set in place to protect the environment from harmful pesticides, BUT lead, mercury, nitrates, and phosphates remain an issue

B) Lead pollution: - Exposure = medical problems (kidney failure, nerve damage, brain disorders, etc..)- Children and babies more susceptible- Lead in fresh water is rarely from natural cause;

a) a big part of the lead in the drinking water comes from the old water pipes. Until the 1950s lead pipes were commonly used for lead last longer than iron.

b) Released into environment by industrial processes particularly ore smelting, manufacturing&recycling of car batteries, the productions of different types of plastics

- The concentrations of lead in the air and oceans have decreased dramatically over the past 30 years. Estimated over 75%, as say some tests. This decrease is caused by the international effort of boycotting and not using leaded gasoline. Canada had banned this substance in 1990

C) Mercury Pollution:- Most mercury compounds are highly toxic- Affect the central nervous system causing symptoms including tremors, irritability, insomnia,

numbness, and tunnel vision- Can also affect the liver and kidneys- Certain mercury exposure are due to natural sources. Ex. Volcanos which are most likely

responsible for around ½ of the mercury present in our atmosphere- Although the leading source of mercury in Canada’s Great Lakes is emissions from coal-fired

power plants. - Other major mercury polluting sources are: gold mines, cement plants, smelters for non-ferrous

metals

D) Nitrate and Phosphate Pollution:- Livestock & nitrogen based fertilizers are the main and greatest source of Nitrate ion in Canada

- Nitrogen based fertilizers find themselves into lakes and rivers = increases the growth of plants and algae. Phosphate ions also increase the growth of aquatic plants. When the bacteria decompose the remains of these plants, the dissolve oxygen is removed from the water = stress on the living organisms of the water particularly during warmer weather where oxygen is naturally lacking

- 1960s = an algal blooms in Lake Eric - High concentration of Nitrate ions in water = harmful to babies less than 3 months old for when

Nitrite ions enter the bloodstream they bond with the hemoglobin = decrease in hemoglobin available to carry oxygen = babies’ tissues become deprived and starved for oxygen, resulting in lips, fingertips to become blue (condition is called: blue-baby syndrome). Older babies are less susceptible since they have a good amount of acid in their stomach which is responsible for inhibiting the bacteria which converts nitrate ions to nitrite

E) Airborne Pollution affect Water Pollution:- Motor vehicles, industries etc.. release CO2, SO2, and Nitrogen Oxide gases. - These non-metallic oxides dissolve into rain water = acid rain which greater the acidity the

greater the amount of various compounds dissolved by it from the soil and rock. - Ex. Aluminum is abundant in Earth’s crust: acidified rain leaches aluminum ions into ground and

surface water which harm the water’s living organisms such as fish who the ions impede the extraction of O@ from the gills

F) Drinking water can also be affected through dissolved substances in bottles. - Clear plastic bottles are made from polycarbonates (hard and clear plastics) which are made

themselves using a chemical called bisphenol A (BPA). BPA can be leached into water through plastic bottles. BPA is known to trigger biological changes such as those cause by estrogen, there are links to breast cancer, and other serious disorders,

- Canada was the 1rst to ban BPA from baby bottles, but it is still used to make a variety of things such as kitchen containers, plates, beverage cans, etc…

- If not properly contained in a recycling or landfill = leaching into environment

Natural pollutants:

http://envimpact.org/node/19SO2 -- a potent acid rain maker. Acid rain damages forests and crops, changes the makeup of soil, and makes lakes and streams acidic and unsuitable for fish. Continued exposure over a long time changes the natural variety of plants and animals in an ecosystem. Moreover, sulfur dioxide is associated with increased risk of respiratory diseases, asthma, and premature death. The toxicity of sulfur dioxide is estimated about 700 times that of carbon dioxide.

http://naei.defra.gov.uk/overview/pollutants?pollutant_id=8

in forming winter-time smog. Studies indicate that SO2 causes nerve stimulation in the lining of the nose and throat. This can cause irritation, coughing and a feeling of chest tightness, which may cause the airways to narrow. People suffering from asthma are considered to be particularly sensitive to SO2 concentrations

http://www.air-quality.org.uk/04.php

Oxides of Nitrogen (NOx)

1. NOx is a collective term used to refer to two species of oxides of nitrogen: nitric oxide (NO) and nitrogen dioxide (NO2).

2. Globally, quantities of nitrogen oxides produced naturally (by bacterial and volcanic action and lightning) far outweigh anthropogenic (man-made) emissions. Anthropogenic emissions are mainly due to fossil fuel combustion from both stationary sources, i.e. power generation (21%), and mobile sources, i.e. transport (44%). Other atmospheric contributions come from non-combustion processes, for example nitric acid manufacture, welding processes and the use of explosives.

Volatile Organic Compounds (VOCs)

1. VOCs comprise a very wide range of individual substances, including hydrocarbons, halocarbons and oxygenates. All are organic compounds and of sufficient volatility to exist as vapour in the atmosphere. Methane is an important component of VOCs, its environmental impact principally related to its contribution to global warming and to the production of ozone in the troposphere. Regional effects derive from non-methane VOCs (NMVOCs), such as benzene and toluene.

2. Most measurements of total VOCs are in terms of their carbon content, without analysis as individual compounds. The major contributor to VOCs is normally methane with a local background concentration of 1.6 ppm. Whilst most other individual compounds (e.g. benzene) are present in urban air at concentrations of a few ppb, or less, total NMVOCs will amount to several hundred ppb concentrations.

3. Hydrocarbons are emitted from petrol evaporation and incomplete combustion, and from leakage of natural gas from distribution systems. Oxygenates arise in vehicle exhausts and via atmospheric chemical reactions. Evaporation of solvents, used in paints or industrial degreasing processes, cause a release of hydrocarbons, oxygenates and halocarbons to the atmosphere.

https://stats.oecd.org/glossary/detail.asp?ID=1738

A natural pollutant is a pollutant created by substances of natural origin such as volcanic dust, sea salt particles, photochemically formed ozone, and products of forest fibres, among others.

Ozone is a secondary photochemical pollutant formed near ground level as a result of chemical reactions taking place in sunlight. About 10 to 15% of low level ozone, however, is transported from the upper atmosphere (called the stratosphere), where it is formed by the action of ultraviolet (UV) radiation on oxygen (the ozone layer).

Natural sources of particulate matter are less important than man-made sources. These include volcanoes and dust storms. However, such sources do account for intense high particulate pollution episodes, occurring over relatively short times scales. It is not unknown for Saharan dust to be deposited in the UK after being blown thousands of miles.

Volatile organic compounds (VOCs) are naturally produced by plants and trees. Isoprene is a common VOC emitted by vegetation, and some believe it to be a more significant trigger for asthma an other allergic reactions than man-made irritants. Plant, grass and trees are also a source of pollen, which can act as triggers in some asthmatics. Pollen is in the air year-round, but the concentration is highest during the growing season, from March to the first frosts in autumn.

Natural pollutants found indoors include the dustmite, mould spores and radon gas.

Book def:

- The natural fresh water supply comes from rain and snow which contains dissolved atmospheric gases

- Ex: when CO2 is dissolved in H2O the product – solution – holds similar characteristics as a dilute solution of carbonic acid (CO2(g) + H2O(l) = H2OCO3(aq)). It’s a slightly acidic liquid that when it filters through certain materials such as soil and rock it dissolves certain compounds from them.

- Causes leaching of ions into ground water which includes calcium, magnesium, iron(2), carbonate & sulfate : most are harmless to organic life & sometimes beneficial, but in some areas of the world there are concentrations of certain ions which at a high level are dangerous to human health

- Ex. Arsenic: arsenic ions (AsO4)3- are naturally found in ground water located under river deltas where they’ve been deposited as a sediment along with the minerals containing them. In Canada AsO4)3- concentration is less than 5 ppb which is considered as a safe amount BUT in Bangladesh which is the majority delta soil has over 35 million people drinking water that contains over 50ppb of arsenic – linked to cancer, diabetes, etc…

- Ex.2 fluoride: 17th most abundant element in the Earth’s crust and is present in all water. Too many of these ions = staining of teeth , BUT if concentration is less than 1 ppm = teeth resistant to staining for the ions form strong ionic bonds so, + the cations in the tooth enamel = resistance

- Ex. 3. Calcium&Magnesium ions: they can cause Hard Water (water that contains a large concentration of ions which form insoluble compounds with soap)

Desalination:

Books def:

- Most of Earth’s water is too salty to drink for the salt unbalances the flow of substances in and out of cells. Saltwater causes the water to flow out of the cells = dehydration

- The process of obtaining fresh water from saltwater is Desalination- Most desalination plants are located in the Middle East which distill ocean water. - The ocean water is heated and the vapour (free from dissolved substances) is condensed:

Thermal Desalination – is very costly and impractical - Reverse Osmosis: a more energy efficient process for making potable water; these plants are

built in coastal areas where access to ocean water is easy, and the return of the water impurities, such as salt, to the ocean without chemicals and no thermal pollution. It is the process of using a high pressure to force water from the more concentration solution through a semi-permeable membrane resulting in a low concentrated solution.

http://geography.about.com/od/waterandice/a/Water-Desalination.htm

Desalination (also spelled desalinization) is the process of creating fresh water by removing saline (salt) from bodies of salt water. There are varying degrees of salinity in water, which affects the difficulty and expense of treatment, and the level of saline is typically measured in parts per million (ppm).

Water that contains saline levels less than 1,000 ppm is generally considered fresh water, and is safe to drink and use for household and agricultural purposes.

The more concentrated saline is in a body of water, the more energy and effort it takes to desalinize it.

There are numerous methods of desalination described below. Reverse osmosis is currently the most commonly found type of desalination, and multistage flash distillation is the method that currently produces the most amount of desalinated water. Reverse osmosis, forward osmosis, electrodialysis, thermal distillation, multistage flash distillation, multiple-effect distillation,

Cons: Dumping the wasted salt solution back into the ocean makes the process more difficult and has the potential to harms ocean life. The energy required to start up and power desalination plants is a huge expense and because most current power sources are derived from burning fossil fuels, it is generally looked upon as just a matter of choosing one environmental crisis over another. Within the energy issue, nuclear energy is potentially the most cost-effective energy source, but remains largely untapped due to public opinion on having a local nuclear power plant or waste facility. If regions situated away from the coast or in a high altitude try to use desalinated water, it is an even more expensive process. Higher altitudes and far distances require great resources to transport the water from the ocean or body of salt water.

Future: Desalination is process primarily done in developed countries with enough money and resources. If technology continues to produce new methods and better solutions to the issues that exist

today, there would be a whole new water resource for more and more countries that are facing drought, competition for water, and overpopulation. Though there are concerns in the scientific world about replacing our current overuse of water with complete reliance on sea water, it would undoubtedly be at least an option for many people struggling to survive or maintain their standard of living. http://idadesal.org/desalination-101/desalination-overview/