The Burden of Thirst

This article was about how people in the town of Konso, Ethiopia don’t have the resources and access to clean drinking water. A woman named Aylito Binayo is one of many who travel down the mountain in order to get water three to five times a day. They may wait hours to get water after a long many hour journey. In this country, women are not able to get an education due to their responsibilities of taking care of the children, getting water, and cleaning their living spaces. According to society expectations, women who “sit and stay at home and do nothing, nobody likes. But if they run up and down to get water, they say she is a clever woman and works hard."

An organization called WaterAid is trying to help give clean, fresh water to poorer places like Konso where clean water is scarce. Other organizations have come to help places like this by providing water resources, but only a few lasted. The ones that didn’t last were either too difficult to fix or people didn’t trust another person with their money in order to buy another part for the resource. When Aylito was asked to imagine an easier life and what she would do, she said “she will go the fields to help her husband, collect grass for the goats, make food for her family, clean the living space, and be with her sons, instead of leaving a grave little four-year-old in charge of his younger brothers for hours on end.” Her hopes for her family’s better life was “to get through the new hunger brought on by the drought, to get through this new wave of disease--to scramble back to the meager life she had known before. She doesn't dream. She has never dared think that someday life could change for the better--that there could arrive a metal spigot, out of the end of which gushed dignity.”

Link: http://web.ebscohost.com/ehost/detail?sid=d0696852-233a-4274-8e50-7d9eabf0c534%40sessionmgr110&vid=1&hid=119&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d 

Water Pollution or Water Shortage??

I believe that Water Pollution is worse than water shortage. Polluted water involves any toxins that can harm humans or the environment. Water pollution is worse because with polluted water, it can make the people who drink it sick with diseases, like in third-world countries, where  many people are dying due to the inability to have clean water. Also, the environment is affected because polluted water gets into main water systems like oceans and can badly affect the animals who live there or the plant wildlife it comes into contact with. 

Chemistry Homework #12

Pg 102 #1-9, 18-22

1.     Make a diagram of the hydrologic cycle and label all processes.

2.     List three major processes that occur in the natural water purification and, for each, identify the contaminants that the process removes.

a.     SAND AND GRAVEL FILTRATION: pure rainwater seeps through the ground and encounters bacteria. If it is exposed long enough, all of the organic contaminants and suspended matter would be removed.

b.     EVAPORATION: leaves behind minerals and other dissolved substances.

c.      BACTERIAL ACTION: converts dissolved organic contaminants into a few simple compounds. 

3.     How are the properties of aluminum hydroxide related to the process of flocculation?

a.     The properties of aluminum hydroxide are related to the process of flocculation because it is a stick, jellylike material that traps and removes the suspended particles, a process called flocculation. Operators then allow the aluminum hydroxide and other solids remaining in the water to settle to the tank bottom. They remove any suspended materials that do not settle out by filtering the water through the sand.

4.     Why is calcium oxide (CaO) sometimes added in the final steps of municipal water treatment?

a.     Calcium oxide is sometimes added in the final steps of municipal water treatment to neutralize acidic water, thus raising its pH to a proper level.

5.     Fluoride, an ingredient in many types of toothpaste, is sometimes added to municipal water supplies in the last stage of water treatment. How much fluoride is added and what is its purpose?

a.     1 ppm of fluoride is added to the water in a process called fluoridation because the fluoride ions can reduce tooth decay.

6.     What are the advantages of chlorinated drinking water compared to untreated water?

a.     The advantage of chlorinated drinking water compared to untreated water is that chlorinated water is free from disease-producing microorganisms because the chlorine kills the organisms.

7.     Is there a disadvantage to using chlorination in water treatment?

a.     There is a disadvantage to using chlorination. It is that trihalomethanes (THMs) can develop. A common one is called chloroform, which is a carcinogen, and is known to cause cancer.

8.     Water from a clear mountain stream may require chlorination to make it safe for drinking. Explain.

a.     The water may require chlorination in order to remove any bacteria or other harmful microorganisms because if not dealt with in the correct way, the bacteria could remain in the water and be very dangerous for humans, no matter how much cleaner the water looks.

9.     List two alternatives to the use of chlorination in municipal water treatment.

a.     CHARCOAL FILTER: activated charcoal can remove most organic compounds from water, including THMs.

b.     OZONE OR ULTRAVIOLET LIGHT: this can completely eliminate chlorine to disinfect the water.

18. Explain what would happen to the Earth’s hydrologic cycle if water evaporation suddenly stopped.

a.     If water evaporation suddenly stopped, the hydrologic cycle would be interrupted and water purity would be diminished and more expensive. Within evaporation the water gets purified and falls down as precipitation as pure water. Once the water hits the ground it then becomes impure again, but is easily purified because less bacteria and other microorganisms are within the water.

19. One unique characteristic of water is that it is present in all three physical states (solid, liquid, gas) in the range of temperatures found on Earth. How would the hydrologic cycle be different if this were not true?

a.     The hydrologic cycle would be different if this were not true because purification would not be possible through evaporation gas were not available. If liquid water were not available, there would be no human race. If the solid state of gas were not available, the land masses would all be underwater.

20. Why does the EPA limit the concentration of THMs to 80 ppb instead of requiring their total elimination from municipal water supplies?

a.      The possible health risks involved.

21. Compare how the various processes used in the foul-water investigation (page 10) are similar to the steps in the natural purification of water.

a.     They are similar because sand and gravel filtration helps filter out any solid or suspended materials in the foul water lab, similar to in the natural cycle. Similarly, the charcoal filtration was like having the water purified through rocks that contain dissolved minerals.

22. Some physicians recommend consuming about 2 L of water daily. Municipal supplies may contain up to 1 ppm fluoride. Assume that you drink 2 L of water per day. At 1ppm fluoride, how many grams of fluoride ion would you consume in:

a.     One day: 2 ppm fluoride

b.     One week: 14 ppm fluoride

c.      One year: 730 ppm fluoride

Hydrologic Cycle

The sun provides energy for water to evaporate. Evaporation leaves behind minerals and other dissolved substances. Water vapor falls and condenses as precipitation, which runs of the land to join the surface water sources or groundwater sources beneath Earth’s surface. Here, bacteria remove any organic contaminants that are within the water that has entered the ground, if exposed for a long enough time. Another process endured by the groundwater is sand and gravel filtration, which removes any suspended material. Any water—when returned to the surface—can evaporated and continue flowing through the hydrologic cycle. Throughout the cycle, evaporation, bacterial action, and filtration purify water. 

Solubility

Solubility curve

Solubility is the maximum quantity of a substance that will dissolve in a certain quantity of water at a specified temperature. A saturated solution is a solution that has crystals that form at the bottom that will not be dissolved no matter how vigorously stirred. An unsaturated solution is a solution that contains less dissolved solute than the amount that the solvent can normally hold at that temperature. A supersaturated solution is a solution that is unstable and contains more solute than my usually be dissolved at a cooler temperature. The solution is cooled without causing any crystals to form. 

Chemistry Homework #11

Oil and water

cooking oil

Water

Pg 83-84 # 20-27, 33, 35

20. Using Figure 1.44 on page 70, decide which is more acidic:

a.     A soft drink or a tomato: Soft drink

b.     Black coffee or pure water: Black coffee

c.      Milk of magnesia or household ammonia: Milk of magnesia

21. How many times more acidic is a solution at pH 2.0 than a solution at pH 4.0?

a.     pH 4.0 is 20 times more acidic than pH 4.0.

22. List three negative effects of inappropriate pH levels on aquatic organisms.

a.     HIGH ACIDITY: fish-egg development is impaired, thus hampering the ability of fish to reproduce.

b.     ACIDIC: increased concentration of metal ions in natural waters by leaching metal ions from surrounding soil.

c.      BASIC CONTAMINATION: alkaline solutions are able to dissolve organic materials, including skin and scales.

23. Distinguish between polar and nonpolar molecules.

a.     POLAR: Water molecules are polar. Water is a common example of a polar solvent. Such charge separation (and resulting molecular polarity) is found in many molecules whose atoms have sufficiently different electronegativities. Polar molecules tend to dissolve readily in polar solvents, such as water.

b.     NONPOLAR: Nonpolar molecules (such as those of oil and gasoline) do not dissolve well in polar solvents (such as water or ethanol). Also, they readily dissolve nonpolar molecules.

24. Would you select ethanol, water, or lamp oil to dissolve a nonpolar molecular substance? Explain.

a.     I would select lamp oil to dissolve a nonpolar molecular substance because nonpolar substances dissolve in nonpolar solvents and different types of oil are nonpolar solvents.

25. Why does table salt (NaCl) dissolve in water but not in cooking oil?

a.     Table salt dissolves in water but not in cooking oil because table salt is a polar substance, similar to water, which helps to dissolve the substance while in oil, the polarity of the salt would not dissolve in the nonpolarity of oil.

26. Explain the phrase “like dissolves like”.

a.     This phrase means the pattern of solubility. The pattern of solubility is that polar substances dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents.

27. Explain why you cannot satisfactorily clean greasy dishes with just plain water.

a.     You cannot satisfactorily clean greasy dishes with just plain water because a nonpolar solvent cannot dissolve a polar substance.

33. Many mechanics prefer to use waterless hand cleaners to clean their greasy hands. Explain

a.     What kind of materials are likely to be found in these cleaners.

                                               i.     Materials likely to be found in those cleaners are nonpolar substances.

b.     Why using these cleaners is more effective than washing with water.

                                               i.     Using those cleaners is more effective than washing with water due to the polar nature of water.

35. Fluorine has the highest electronegativity of any element. Fluorine and hydrogen form a polar bond. Which atom in HF would you expect to have a partial positive charge? Explain.

a.     I would expect the Hydrogen atom to have a partial positive charge because Hydrogen as an ion has a positive charge, and never negative, similar to how Fluorine always has a negative ion charge.

Unit 1C Vocab

·      SATURATED: when crystals of a substance will remain undissolved- as a solid- on the bottom of the container, no matter how long you vigorously stir

·      SOLUBILITY: the maximum quantity of substance that will dissolve in a certain quantity of water at a specified temperature

·      SOLUBILITY CURVE: the graphical representation of the relationship of the water temperature when it changes from 0 degrees Celsius to 100 degrees Celsius.

·      UNSATURATED SOLUTION: a solution that contains less dissolved solute than the amount that the solvent can normally hold at that temperature.

·      SUPERSATURATED SOLUTION: when you can cool a saturated solution without causing any solid crystals to form, producing an unstable solution that contains more solute than could usually be dissolved at that temperature.

·      POLAR MOLECULE: has an uneven distribution of electrical charge, which means that each molecule has a partial positive region at one end and a partial negative region at the other end.

·      CONCENTRATION: refers to how much solute is dissolved in a specific quantity of solvent or solution.

·      PERCENT: parts solute per hundred total parts (solute plus solvent)

·      PARTS PER MILLION: an expression of concentration; the number of units of solute found in one million units of solution (0.0010% = 10 ppm)

·      PARTS PER BILLION: an expression of concentration; the number of units of solute found in one billion units of solution (0.00010% = 10 ppb)

·      HEAVY-METAL IONS: their atoms have greater masses than those of essential metallic elements and are harmful to humans and other organisms.

·      GREEN CHEMISTRY: prevents pollution by eliminating the production and use of hazardous substances.

·      pH  SCALE: a convenient way to measure and report the acidic, basic, or chemically neutral character of a solution.

·      ALKALINE: basic solutions

·      ACIDS: made up of molecules including one or more hydrogen atoms that can be released rather easily in water solution.

·      BASES: ionic substances that include hydroxide ions (OH^-)

·      MOLECULAR SUBSTANCES: substances that dissolve in water but not as ions.

·      ELECTRONEGATIVITY: the ability of an element’s atoms to attract shared electrons when bonding within a compound.

Unit 1B Vocab

      ·      MATTER: anything that occupies space and has mass.

·      PHYSICAL PROPERTIES: properties that can be observed and measured without changing the chemical makeup of the substance.

·      DENSITY: the mass of material within a given volume.

·      FREEZING POINT: a physical property; 0 degrees Celsius at normal atmospheric pressure.

·      AQUEOUS SOLUTION: water-base solution

·      MIXTURE: when two or more substances combine, and yet still retain their individual properties.

·      HETEROGENEOUS MIXTURE: its composition is not the same, or uniform, throughout. (ex. Foul water)

·      SUSPENSION: a heterogeneous mixture; if solid particles are large enough to settle out, or can be separated by using filtration.

·      TYNDALL EFFECT: the scattering of light, which indicates that small, solid particles were still in the water.

·      COLLOID: a mixture of small, solid particles.

·      HOMOGENEOUS MIXTURE: a mixture that is uniform throughout.

·      SOLUTION: homogeneous mixtures

·      SOLUTE: the dissolved substance

·      SOLVENT: the dissolving agent

·      PARTICULATE LEVEL: the level of atoms and molecules.

·      ATOMS: the building blocks of matter.

·      ELEMENT: matter that is made up of only one kind of element.

·      COMPOUND: a substance that is composed of two or more elements linked together chemically in certain fixed proportions.

·      CHEMICAL FORMULAS: how compounds and elements are represented.

·      SUBSTANCE: each has a uniform and definite composition, as well as distinct properties.

·      MOLECULE: the smallest unit of a molecular compound that retains the properties of that substance.

·      MACROSCOPIC: a world filled with large-scale (macro) readily observed things.

·      MODELS: representations

·      CHEMICAL SYMBOLS: the letters in an international “chemical language” understood by scientists throughout the world.

·      PERIODIC TABLE OF ELEMENTS: where all known elements are organized, and one of the most useful tools of a chemists work.

·      SUBSCRIPT: a number written below the normal line of letters.

·      CHEMICAL EQUATIONS: can be regarded as chemical sentences.

·      CHEMICAL REACTIONS: entail the breaking and forming of chemical bonds, causing atoms to be rearranged into new substances.

·      REACTANTS: the original (starting) substances in a chemical reaction.

·      PRODUCTS: the new substance or substances formed form the rearrangement of the reactant atoms

·      DIATOMIC MOLECULES: they exist as two bonded atoms of the same element

·      PROTONS: positively charged particles

·      ELECTRONS: negatively charged particles

·      NEUTRONS: electrically neutral particles

·      IONS: electrically charged atoms or groups of atoms

·      IONIC COMPOUNDS: substances that are composed of positive and negative ions

·      ANION: a negatively charged ion

·      CATION: a positively charged ion

·      POLYATOMIC ION: an ion consisting of a group of bonded atoms

·      CONFIRMING TESTS: a positive test confirms that the ion in question is present.

·      PRECIPITATE: an insoluble material

·      QUALITITATIVE TEST: tests that identify the presence or absence of an ion

·      QUANTITATIVE TEST: determine the amount of a specific substance present in a sample.

·      REFERENCE SOLUTION: a solution of known composition used as a comparison

·      DATA: objective pieces of information