Water Shortage v.s. Water Pollution: Which is Worse?

   
  Water pollution and shortage are both life-threatening situations. In both scenarios the water supply is affected, whether it is not there or unusable. However, a water shortage is definitely more serious. It is said that humans can go almost one month without food, but cannot last a week without water. It is difficult to find more sources of water, especially in a dry climate. For example, people in poor countries must walk miles to get to a lake or stream. However, if that supply ran out they must search for another source. But that source may be inexistent or even farther out. Digging for water is an option, but some people may not have the resources to dig that far. Even if water was shipped out to them, it could take days. A shortage of water could lead to bigger problems as well. Wars over precious water sources could arise as people become desperate for water. Although we have not reached that level of seriousness yet, it may not be so far off. Water pollution on the other hand is easily solved by the technology we have. There are many, many ways to purify water, and nature can even do it themselves. Filtration, distillation, and chlorination are just a few of the way to cleanse water. Even if water is polluted in areas where these innovations are unavailable, boiling water is a quick and cheap way to remove most impurities. Water is one of the most important substances on earth, and not having enough of it is a deadly problem. 

Water Shortage

Review Term: The Tyndall Effect

The Tyndall effect is the scattering of light, indicating that small solid particles are in a substance. It also tells you if that mixture is a solution, colloid, or suspension. If a mixture is a solution, and a light is shone through, then you will not see the beam of light in the liquid. Instead, a dot of light on either side indicates that the particles inside are not big enough the reflect the light. If the liquid happens to be a colloid, then the light will pass through, even if it appears to be homogenous. For a suspension, one of two things can happen. If the particles are the right size then the beam of light will appear. However, if the suspended particles are too large, they will block the light instead of reflecting it. 

Section D Summary: 1-9. 18-22

    1.    On paper.

    2.    During evaporation dissolved substances in the water are removed (like salt, heavy metals and minerals). When water is running through the ground suspended particles are filtered out through the sand and rocks. Also, when water is in its groundwater stage, bacteria in the dirt kill other organic substances that are found in the water.

    3.    Aluminum hydroxide, which is a sticky, jelly-like material, is used during water treatment processes. It is mixed with water and clings to the suspended particles in there. The water then sits for a bit, allowing the aluminum hydroxide drop to the bottom with the suspended particles. This process is called flocculation.

    4.    Calcium oxide, or lime, is a basic substance sometimes added to further purify water. It helps because it neutralizes the slight acidity in water that is being treated.

    5.    In the final steps of water treatments sometimes 1 ppm of fluoride is added to the water during a process called fluoridation. This substance helps reduce teeth decay and is also found in toothpaste.

    6.    Chlorinated drinking water is less likely to have bacteria in it because chlorine kills those substances. Also, even if some type of bacteria-fighting substance is added, it may not continue to fight off the bacteria like chlorine does.

    7.    Yes, there is. Chlorine in water sometimes reacts with organic compounds called and if the concentration of these compounds gets too high iy van be harmful to human health. Some of these compounds are called trihalomethanes, and include chloroform, which can cause cancer.

    8.    Even if water in a stream appears clear and safe to drink, bacterial substances are most likely present. Therefore chlorine is needed to kill those substances and make it safe to drink.

    9.    Two alternatives to chlorination would be charcoal filtration and using ultraviolet light. Charcoal filtration would properly filter out most organic compounds, but it is a very expensive process to uphold. Ultraviolet light eliminates bacteria, but cannot protect the water once it leaves the plant. It is also dangerous if not handled properly.

    18.  If evaporation stopped, then the dissolved liquids in water would not be able to be removed naturally. Also, the volume of rivers, lakes, streams, and oceans would go up because there is no place for the water to go. Another problem would be the lack of rain. With no water rising into the atmosphere, no clouds can form to create rain. Evaporation is a very crucial and helpful step in nature’s water cycle.

    19. If water was not present in all 3 stages on earth, there would be no point for the water cycle. The water cycle is basically water changing between its forms, but without them this cycle is useless.

    20.  It limits it because even though they are dangerous we still need the chlorine. The effects if THMs is not huge compared to the need of chlorine.

    21. The steps are similar because we have evaporation, which is like distillation, filtration through the sand, and there is probably charcoal in ground as well.

    22.  I don’t know.

Heavy-metal Ions

  
  Heavy metal ions are called heavy because their masses are heavier than that of essential metallic ions. These ions are not essential because they are toxic to living organisms and are capable of causing death. They are present in both foods and drinking water, and are toxic because they prevent proteins in our bodies from performing their duty by binding to them. This makes the effects of heavy metal poisoning severe and can damage your nervous system, brain, kidneys, and liver. Some heavy metal ions include lead, mercury, and aluminum. The concentration of these ions increase as they are consumed by fish and shellfish, which makes consuming seafood dangerous in large amounts. Mercury and lead are most harmful because they are used in a lot of products. Lead, for example, is used in pottery, cooking vessels, pesticides, and paints. In the early 1800's lead was even used in pipes, contaminating the water. Mercury is used fluorescent light bulbs, thermometers, and paints. Unfortunately, if mercury (the only metallic element that is a liquid at room temperature) is exposed to the air, its vapor can escape and can be inhaled or absorbed through the skin. This is what happened to hat makers in the 18th and 19th centuries. Mercury was used in felt hats and the workers came down with mercury poisoning which can cause numbness, staggered walk, tunnel vision, and brain damage. Those affected by it were referred to as, "mad as a hatter." To remove these harmful ions from entering the atmosphere and our water practices called Green Chemistry are used. These practices prevent pollution by eliminating the production and use of hazardous substances. To ensure our safety and health, using alternatives to these deadly ions help greatly. 

Section C Summary: #20-27, 33 & 35.

20.  

a. A soft drink is more acidic because it has a pH of 3, while a tomato’s pH is only about 4.

b. Black coffee is more acidic with a pH of 5, and pure water’s is 7.

Milk of magnesia, while it is a base, is more acidic than household ammonia.

21. The pH scale goes by increments of 10, so a pH solution of 2.0 is 100 times stronger than a solution with a 4.0 pH.

22. Inappropriate pH levels have various effects on aquatic organisms. For example, if water is too basic it can dissolve fish scales. Another example would be if the acidity level got to high, increasing the metal ion concentration, some of which, like aluminum, are toxic to fish. Also, high acidity can affect fish-egg development, causing an inability for fish to reproduce.

23. Polar molecules have an uneven electrical charge distribution, while non-polar molecules have an equal balance of positive and negative charges.

24. I would use lamp oil to dissolve a non-polar molecular substance since it is also non-polar. Water and ethanol are both polar and would be ineffective in dissolving a non-polar solute because “like dissolves like.”

25. Table salt would dissolve in water, but not oil, because both it and water are polar substances, and oil is not.

26. The term, “like dissolves like” means that a non-polar solvent dissolves a non-polar solute, and a polar solvent will dissolve a polar solute. However, this does not mean that non-polar substances are completely insoluble in water. They will dissolve to a certain extent, but not enough to be totally soluble.

27. Water cannot satisfactorily clean greasy dishes because the grease is an oily substance, making it non-polar. Although the water may rinse away the oils, it cannot fully dissolve them. A non=polar cleaning fluid would be more effective for this.

33.  

a. There are likely going to be non-polar materials like carbon dioxide

b. This is more effective because the non-polar materials will dissolve the non-polar oils on mechanics’’ hands, while water will kind of rinse it off.

35.   I would think that hydrogen would have the slightly positive charge. This is because fluorine naturally has more electrons, which would most likely stay attracted to it, leaving hydrogen with almost no electrons.

Section C Summary: #1-19 p. 82-83

   9.    Sugar= 11g, Water= 44g

   10. 15,000 ppm.

   11.A water molecule is made polar because its hydrogen atoms are positive, and its oxygen atom is negative. Therefore it has both a positive and negative end, and attracts both kinds of ions.

   12.On paper.

   13. Water’s polar nature:

a.    The oxygen, or negative, side.

b.    The hydrogen, or positive, side.

   14.They are called heavy because their masses are greater than those of essential metallic elements.

   15.Numbness, tunnel vision, and brain damage.

   16.  Human exposure:

a.    Lead: People could be exposed to lead through some paints or pottery that contains it.

b.    Mercury: Human exposure to lead could come through a thermometer or a pesticide.

   17. Hydroxide ions.

   18. Hydrogen.

   19.Acidic, Basic, or neutral:

a.    Slightly basic.

b.    Basic.

c.    Acidic.

d.    Neutral.

Extra Credit Summary: Air Pollution

      The air outside our homes may be filled with gases and molecules that are unhealthy for us, but it also contains large amounts of fresh oxygen--something the air inside our homes don’t have. In the article, “Invisible Toxins in Your Living Room,” the author gives detailed instructions on how to clear the air in your house. In your lifetime, you spend 60% of it in your house. Although the air may seem safe, it really isn’t. Fumes such as carbon dioxide, carbon monoxide, mold, and dust are constantly in the air you breathe. Especially during the winter, when most of the windows and dorrs remain closed, large amount of carbon dioxide can build up without being properly released. This is dangerous especially if you have asthma, or respiratory problems because those particles can enter your lungs. Here are a few tips to airing out your home: 

Leaving the windows open in your room before and after you go to bed lets all the CO2 that has accumulated escape and provides better sleeping conditions.  

Using scented candles gives off a nice smell, but also release “particulates”,which are tiny bits of pollution. Instead, using unscented candles will still give off a warm glow, without the irritating toxins. 

 Another way to provide healthier air in your home is to clean out filters in air conditioners and heating vents. Dust and mold that collcts on the filters just enters the air whenever the air is turned on. By replacing the filters, purer air is guaranteed. If we care about the air outside, then we should care much more about the air in our homes. 

Article: The Invisible Toxins in Your Living Room.
http://web.ebscohost.com/ehost/detail?sid=90ab619b-e80a-45bc-b7ce-a05122cbf52a%40sessionmgr12&vid=9&hid=7&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=ulh&AN=55274186

Lab Demo: 6-23-11

C.5 Questions: page 62, 1-3

   1.       

a.    There would be a lot more solute in the water, so the substance would look white.

b.    On paper.

   2.       

a.    On paper

b.      

                                               i.     On paper

                                              ii.     50g water have to evaporate.

   3.      

a.    On paper

b.    On paper

c.    The key difference is that there is way more qater in 3.b than 3.a. This is because there is twice as much water in 3.b, so the KCl ions just get lost in all the solvent.

        

         

Review List

For the test on Friday, I would like to review a few things: 

1. Distillation
2. The SI System
3. Unit Conversions
4. The pH system 

Section C Summary: 1-8

    

   1.    More sugar will dissolve in hot tea instead of iced tea because heat affects the solubility of a substance. The higher the temperature is, the more substance that can be dissolved in a solvent.

   2.    48g KCl.

   3.    Solubility of sugar:

a.    200g of sugar

b.    710g

c.    1892g

   4.      

a.    NaCl, KCl, KNO3

b.    KNO3, KCl, NaCl

   5.    Saturated means that a solution has received the maximum amount of solute that can be dissolved, while unsaturated is a solution that contains less dissolved solute than possible at that temperature.

6.    Potassium Nitrate:

a.    31g

b.    Supersaturated.

c.    70g of KNO3 should form.

   7.    More potassium nitrate:

a.    Nothing, just more solute will be in the substance, but it could become saturated if only that one crystal was needed.

b.    It will become supersaturated, or the crystal will just float to the bottom.

c.    The extra crystal will be disturbed and reform.

   8.    30% ethanol/water. 

C.2 Questions: 1-3

   1.    Solubility curve:

a.    105g of KNO3 will dissolve in 100g of water at 60°C.

b.    45g of KCl will dissolve in 100g of water at 60°C.

   2.    Proportions:

a.    20 more grams of KNO3 is needed.

b.    55.6g H2O.

   3.    More proportions:

a.    50g of KNO3

b.    187.5g of H2O 

Water Testing Lab

During this lab I learned that although many precise measures can be taken to see how pure your water is, nothing can completely make our water pure. Although tests can tell us if there is a substance in it or not, it can never be positive, at least not from the tests we've learned about so far. I also have discovered that it is important to check through all the steps of a lab carefully, one mistake and it can change all the results. Even though careful precautions can be taken, there are always going to be unavoidable mistakes. 

Section b Summary: 25-34 p. 52

25. Qualitative tests tell us if there are particles present in the sample, while quantitative tests let us know how much of a substance is present.

26.A confirming test is a laboratory test giving a positive result if a particular chemical species is present.

27.

a.    A reference solution is used to compare a sample to, to see if it its result is positive.

b.    A blank, on the other hand, is used as a comparison to see if the sample does not have ion.

28. No, the student has to see if there is any precipitate, because the iron ion may not have a change in color in that sample of groundwater.

29.

a.    I would first let it sit, because if it were a solution then the suspended particles would separate from the substance. The Tyndall effect would also be helpful to see if the particles are large enough to reflect the light. A filtering process could be used as well, to see if there is any change in the substance after it has been filtered. Also, if the substance seems pure, an electrical conductivity test may be performed to see if there are any particles that conduct electricity present in the substance. Lastly. These confirming tests may be used to see if there are ions that have mixed into the substance.

b.    Letting the substance sit would tell us if it is a suspension, since suspended particles do not remain mixed for long. The Tyndall effect could let us know if it was a colloid or suspension, or a solution since larger particles reflect the light. Filtering tells us if it is a suspension, since the large particles would not remain in the filtrate, but we would not know if it was a colloid because not all colloid particles can be filtered out. An electrical conductivity test tells us if it is a solution, or pure water, since distilled water contains no salt, which conducts electricity. Finally the confirming tests just tells us if it a solution with particles, or a pure sample with either no ions or just a small amount of them.

30.Failing to follow the “shake before using” instructions in a medicine bottle could result in an ineffective dose of medicine, or consuming substances that are harmful if swallowed alone.

31.It is useful so scientists all over the world can interact and share experiences, without the confusion, of which element is which.

32. See picture.

33. No, it is not, because certain gases such as Nitrogen, Oxygen, and Carbon Dioxide with always dissolve into water. This means whenever water comes in contact with open air, the gases can combine and dissolve within the water.

34.Water is liquid at room temperature, is very rare except for on earth, and has a freezing pint of 0 degrees centigrade. Hydrogen and Oxygen are both gases at room temperature, and while oxygen is not abundant outside of earth, hydrogen is. Also the freezing points of oxygen and hydrogen are -222.65 degrees centigrade and -258.975 degrees centigrade, respectively.

How Does Water Testing Hep Us?

  
   Water testing has many benefits to the health and welfare of people. Ions are unseen to the naked eyes, and we can drink  supposedly harmful ones unknowingly. Water testing lets us know if there are substances in the water that we should not consume. Although some added compounds may be good for us, there are most likely a select few that can be hurtful. even if water testing goes on behind closed doors of a factory or laboratory, it greatly aids the nature of the water we drink. 

Section B Summary: 19-24 p. 51

19. How many to make it neutral:

a.    6 electrons

b.    13 protons

c.    82 electrons

d.    17 protons

20.Neutral or not:

a.    No

b.    No

c.    Yes

d.    No

21.Anion, cation, or neutral:

a.    Anion

b.    Neutral

c.    Neutral

d.    Cation

e.    Cation

22.Gaining or losing electrons:

a.    Gaining electrons

b.    Neither

c.    Neither

d.    Losing electrons

e.    Losing electrons

23.Symbol and Charge:

a.    H

b.    Na+

c.    Cl-

d.    Al3+

24.Ionic compounds:

a.    KI; potassium iodine.

b.    CaS; calcium sulfide.

c.    Fe3+(Br-); iron(II) bromide.

d.    Ba2+(OH-)2; barium hydroxide.

e.    (NH4+)3 PO43-; sodium phosphate.

f.     Al3+(O2-); aluminum oxide.

Water Use Analysis (p. 20-21)

 

          
           

1.    The total water use for 3 days: 6,347.5 L

2.    The average amount of water used per day by one person: 528 L

3.    Average daily water use (graph on paper) 

Rana: 289 L

Katrina: 216 L

Nia: 499 L

Nicolai: 510 L

Dana: 291 L

Alex: 472 L

Rebecca: 950 L

Eva: 216 L

Camilla: 459 L

Oliver: 527 L

Eden: 528 L

Chase: 363 L

Mike: 490 L

4.    Range: 734 L

5.    Mean: 450 L

Median: 472 L

The mean is more representative of the amount of liters used by one person daily since it takes a compilation of the numbers.

6.    It is different because there are various situations affecting the use of water such as lawn size, or different numbers of bathrooms in the house. Also, not all houses have water-saving appliances, and the family may not be home as much as another family.

7.    The class average is closer to the national average since this is a range of more people and there are a variety of situations affecting the amount of water used. 

Water Table Summary

1. 3 days= 6312.3 L total


2. 1 household member per day= 526 L 

Section B Summary: 13-18 p. 50-51

14.

a.    i, ii, iv, vi

b.    iii, v

15. It tells us what types of atoms are in a compound and how many atoms of each.

16.

a.    3 hydrogen atoms, 1 phosphorous atom, and 4 oxygen atoms.

b.    1 sodium atom, 1 oxygen atom, and 1 hydrogen atom.

c.    1 sulfur atom and 2 oxygen atoms.

17.

               c.

·      A hydrogen gas molecule reacts with a chlorine gas molecule to produce two hydrogen chloride molecules.

·      Two aqueous hydrogen peroxide molecules produces two liquid water molecules and an oxygen gas molecules.

18.

a.    NaHCO3 + HCl à NaCl + H2O + CO2

b.    C6H12O6 + 6O2 à 6CO2 + 6H2O

B.5 #1-3 page 33

2. The model represents a heterogeneous mixture of compounds. The two types of molecules are separated, one at the top and the other at the bottom. They are also compounds, since the molecules contain different types of atoms.

3.

a)                   I made this model mixture heterogeneous, since not all mixtures are distributed evenly. I also drew the Z element large and single-atomed, and the X element with two tiny atoms.

b)                   This compound model has two atoms of different elements, and I drew a line to signify the chemical bond.

c)                   For this 4-atomed compound I drew one large atom with three tiny atoms of the element attached to it (no lines).

d)                   This model is a solution, so the molecules are evenly mixed. Also, both the solute and the solvent are compounds with two atoms.