day 4 week 2

1. a. As the solution cooled, a precipitate would form in the solution.
    b. on paper


2. a. on paper
    b. i- on paper ii- 50g must evaporate in order to form a saturated solution.


3. a. on paper
    b. on paper
    c. In example a, the percent concentration is higher than it is in example b since more water was added to the solution.

extra credit assignment #2

The Scoop on Eating Dirt

• Geophagia, an eating disorder in which people consume things that are not food, is not necessarily abnormal, as a group of students at Tufts University discovered. 

• A question has risen over the years- is geophagia abnormal or adaptive? Today it is clear that geophagia is more widespread in the animal wildlife than what was previously thought. 

• Some indigenous people in the Americas used dirt as a spice and prepared naturally bitter foods such as acorns and potatoes with a little bit of clay to balance out the sharp taste. 

• One of the main reasons as to why animals and people consume dirt is that soil contains minerals, like calcium, sodium, and iron, that support energy production and other vital biological processes. 

• Among human populations in Africa, those who already have access to calcium do not practice geophagia as often as those who do not have access to calcium. The need for calcium also explains why geophagia is commonly associated with pregnancy, because a mother needs extra calcium as the fetal skeleton develops. 

•  Eating dirt is also a form of detoxification, because negatively charged clay molecules easily bind to positively charged toxins in the stomach, which prevents those toxins from entering the bloodstream by carrying them out of the body in the feces. 

• Of course, ingesting dirt can also be poisonous. Along with detoxifying minerals, you might unintentionally ingest bacteria, viruses, parasitic worms, and dangerous amounts of lead. 

• As a whole, the evidence argues that geophagia is not a sign of a mental illness. It is a specific defense. 

• I think that eating dirt is beneficial only to those who are deficient of certain minerals or have certain disorders. If it isn't necessary for you to consume dirt, then I would avoid it. 

Why people eat dirt: 

Anemia- 75%

Gastrointestinal distress- 96% 

Hunger- 22%

Craving- 93%

http://www.scientificamerican.com/article.cfm?id=would-you-like-side-dirt-eating-soil

practice questions

1. pH is the measure of acidity to alkalinity. An example of an acid is vinegar, and example of a neutral substance is water, and an example of a base is ammonia. 


2. 27.8 m/s. 


3. 0.000905 kg. Decimal is moved 6 places.


4. The charge of an electron is -1, the charge of a proton is +1, and the charge of a neutron is neutral. 


5. An anion is negative and a cation is positive. An anion is formed by gaining one electron, and a cation is formed by losing one electron. 


6. The first column on the periodic table (Na, K) tends to lose one electron. 


7. The second column on the periodic table (Mg, Ca) tends to lose two electrons. 


8. The sixth column on the periodic table (O, S) tends to gain two electrons.


9. The seventh column on the periodic table (F, Cl) tends to gain one electron. 


10. The eighth column on the periodic table (He, Ne) tends to remain neutral. This column is called the noble gases. 


11. Fluorine is a negative ion, and Mg is a positive ion. 


12. An atom is composed of a nucleus containing protons and neutrons on the inside, and electrons on the outside. 


13. Water can't be 100% pure because there are atmospheric gases that will always dissolve in water. 


14. We can help dissolve more solute in water by rising the temperature. 


15. KI is an ionic compound formed from K+ and I-. BaOH is an ionic compound formed from Ba+ and OH-. AlO is an ionic compound formed from Al3 and O2-. 


16. The atomic symbol for Mercury is Hg. It's atomic number is 80  and it's atomic weight is 200. There are 80 protons and 80 electrons, and 130 neutrons. 

day 3 week 2

#1 C.2:


1. a. 105g of potassium nitrate will dissolve in 100g of water at 60 C.
    b. 45g of potassium chloride will dissolve in 100g of water at 60 C.


2. a. 20g of potassium nitrate must be added to form a saturated solution at 30 C.
    b. 45g is the minimum mass of 30 C water that is needed to dissolve 25 g potassium nitrate.


3. on paper


#2 ISCS: 


1. Three teaspoons of sugar will completely dissolve in a serving of hot tea but will not dissolved in an equally sized serving of iced tea because of the temperature difference


2. The maximum mass of potassium chloride that will dissolve in 100.0g water at 70 C is 48.


3. a. on paper
    b. on paper
    c. on paper


4. a. 20 C - NaCl, KCI, KNO3
    b. 80 C- KNO3, KCI, NaCl


5. Saturated is when a solution remains undissolved as a solid on the bottom of the container, no matter how long you stir it for. Unsaturated is when a solution contains less dissolved solute than the amount that the solvent can normally hold at that temperature.


6. a. 31g is the maximum mass of KNO3 that can dissolve in 100g water if the water temperature is 20 C.
    b. This solution is supersaturated.
    c.  105g of the solid KNO3 should form.


7. a. If you add a crystal of KNO3 to an unsaturated solution, it will become saturated.
    b. If you add a crystal of KNO3 to a saturated solution, it will either remain saturated or become supersaturated.
    c. If you add a crystal or KNO3 to a supersaturated solution, it would cause the crystal to settle to the bottom, becoming a precipitate.


8. on paper


#3 Blog question: 


1. In order to solve these problems, I usually write them out on paper and break apart the problem into steps. Once I've done that, it becomes simpler for me to solve.

day 2 week 2

#1 ISBS:


25. Qualitative tests are tests identify the presence or absence of a particular substance. Quantitative tests are tests that determine the amount of a substance in a sample.


26. A confirming test confirms that the ion is either present or absent.


27. The purpose of the reference solution was to be used as a comparison to a solution of known interest, and the purpose of the distilled water blank a solution known not to contain any ions of interest.


28. If a student tests a sample of groundwater for iron and observes no color change, that student should not conclude that no iron was present because sometimes the amount of the substance is so little that it cannot be detected.


29. Give the mixture time to see whether there is a precipitate. If there is a precipitate then the mixture is a suspension. Shining light through the mixture will tell whether it's a colloid or solution. 


30. If you do not "shake before using" a bottle when you are instructed to, you will consume clumps of the substance, instead of a uniform mixture throughout.


31. Element symbols should have international acceptance so that it is easier to identify no matter where you are in the world.


32.

33. Water cannot be completely chemical free because the atmospheric gases nitrogen and oxygen and carbon dioxide will always dissolve in the water to some extent. 


34. At room temperature, water is a liquid, whereas hydrogen and oxygen are gases.


#2 Blog question: 


1. The purpose of the lab was to learn that if an ion is present, then a confirming reaction will occur in the solution. There were several similarities and differences amongst the different tests, and it was interesting to compare each one. The lab as a whole I thought was difficult at first, because of all of the steps involved, but then after each test the process became easier and easier.

water testing lab

Livia and Adam

Abstract:

The purpose of the water testing lab was to find the presence of an ion in different solutions. In order to complete this procedure, we placed different test solutions, including distilled water, reference solution, control water, tap water, and ocean water, into the wells of a chemplate. Then, for the test of the Calcium ion, we added drops of sodium carbonate into each of the wells, to test whether the ion was present or not. If it was, the solution often turned into a milkier consistency, instead of a clear solution. For the test of the Iron Ion, we placed two drops of potassium thiocynate into the well. In the Chloride Ion test, we placed drops of silver nitrate into the well, and lastly, in the Sulfate Ion test, we added drops of barium chloride to the well. As we completed each of these tests, we discovered the presence of certain ions within these solutions.

Procedure:

Starting with the Calcium Ion test, we placed 20 drops of solution into 5 of the wells on the chemplate. Next, we added four drops of sodium carbonate to each of the 5 wells. Then we recorded our observations. The reference solution, which was calcium chloride, turned out to be the only solution in which the ion was completely present.

  

Then we rinsed out our chemplate and began the Iron (III) Ion test. We started the procedure by adding 20 drops of solution into a well of the chemplate. Then we added two drops of potassium thiocyanate test reagent to each of the wells. The reference, which was the Ferric Nitrate, solution turned out to be the only solution in which the ion was completely present.

  

After rinsing out our chemplate after the Iron test, we started the Chloride Ion test by adding 20 drops of solution into the chemplate. Then we added three drops of silver nitrate test reagent to each of the wells. After recording our observations, we found that the reference solution, calcium chloride, was somewhat milky, but still slightly clear. We also found that the tap water solution became unclear within a few minutes, and the ocean water was extremely unclear and contained the ion.

  

Then we rinsed our chemplate out are started the Sulfate Ion test. We added 20 drops of solution into the chemplate, and then added three drops of barium chloride test reagent into each of the wells. After recording our observations, we found that the reference solution, ferrous sulfate, had a yellowish composition, the control solution was slightly milky and more dense towards the center, and the ocean solution was whiteish and slightly milky.

CALCIUM

Solution	Observations	Result
Distilled	Remained clear	Ion is not present
Reference (Calcium Chloride)	Milky solution, somewhat unclear	Ion is present
Unknown/Control	Remained the same, slightly more foggy	Ion is slightly present
Tap water	Remained clear	Ion is not present
Ocean	Remained clear	Ion is not present

IRON

Solution	Observations	Result
Distilled	Remained clear	Ion is not present
Reference (Ferric Nitrate)	Dark, reddish solution, looks almost like red wine	Ion is present
Unknown/Control	Remained clear	Ion is not present
Tap water	Remained clear	Ion is not present
Ocean	Remained clear	Ion is not present

CHLORIDE

Solution	Observations	Result
Distilled	Remained clear	Ion not present
Reference (Calcium Chloride)	Milky consistency, however still clear	Ion somewhat present
Unknown/Control	Remained clear	Ion not present
Tap water	Became slightly unclear and milky after waiting a few minutes	Ion slightly present
Ocean	Very unclear and milky	Ion present

SULFATE

Solution	Observations	Result
Distilled	Remained the same	Ion is not present
Reference (Ferrous Sulfate)	Yellowish, slightly milky	Ion is present
Unknown/Control	Whiteish, slightly milky and more dense	Ion is present
Tap water	Remained clear	Ion not present
Ocean	Whiteish, slightly milky, cloudy	Ion is present

Lab Questions:


1. A reference solution was a solution of known composition that was used as a comparison, in which contained the sought ion, and the water blank was known not to contain any ions of interest.

2. Qualitative tests identify the presence or absence of a substance in a sample, but the test does not determine the specific amount of a substance in a sample, which is important in certain tests.

3. These tests cannot absolutely confirm the absence of an ion because sometimes the amount of a substance is so little that it cannot be detected.

4. Our observations may have altered if we had not cleaned our chemplate between the tests, because of the possibility of certain chemicals from each solution contaminating the remaining tests.

day 1 week 2

#1 1SBS 


19. a. protons- 6 protons, 6 electrons
     b. aluminum- 13 protons, 13 electrons
     c. lead- 82 protons, 82 electrons
     d. chlorine- 17 protons, 17 electrons


20. a. sulfer- not electrically neutral
     b. iron- not electrically neutral
     c. silver- electrically neutral
     d. iodine- not electrically neutral


21. a. anion b. neutral atom c. neutral atom d. cation e. cation  
      
22. a. lack of electrical charge is from losing electrons 
        b. electrical charge is from neither gaining/losing electrons 
        c. electrical charge is from neither gaining/losing electrons 
        d. electrical charge is from gaining  electrons 
        e. electrical charge is from gaining electrons 


23. a. H b. Na+ c. Cl- d. Al+ 


24. a. KI b. CaS c. (Fe)(Br)3 d. (Ba)(OH)2 e. (NH4)3(PO4) f. (Al)3(O2)


#2 Additional question 


1. Testing water helps us because once water is tested we can then identify specific substances in water solutions. 

water diary

1.  2,937.36 L used by two people in three days.


2. 489.56 L used by one person in one day.


3.

4. 594.5 is the range within the class. 


5. Mean- 530 L Median- 489 L. 


6. The difference between the average volume of water (370 L), and my personal average of 489.56 L is substantial. Showering takes up a lot of water use in my household, as well as the water running in the sink. 


7. My daily water usage by each person is 489 L, which also happens to be the class median. I was below the class average by about 41 L. 

day 5 week 1

# 1 ISBS


13. On paper


14. i, ii, and iv represent elements. iii, v, vi, represent compounds.


15. Compounds and elements are represented by chemical formulas.


16. a. 3 hydrogen atoms, 4 oxygen atoms, 1 phosphorous atom b. 1 sodium atom, 1 oxygen atom, 1 hydrogen atom c. 1 sulfur atom, 2 oxygen atoms


17. On paper


18. a. NaHCO3 + HCI ---> NaCl + H2O + CO2 b. C6H12O6 + O6 ---> 6CO + 6H2O

day 4 week 1

#1 B.5


1. On paper


2. The model represents three different gaseous elements, including oxygen, hydrogen, and nitrogen.


3. On paper

extra credit assignment #1

A new way of making computer memory cards, using bacteria. 

• A group of researches at the University of Leeds, in Britain, discovered naturally occurring proteins that make arrays of tiny magnets, similar to those made to store information in memory cards.
• The researchers took their inspiration from Magnetospirillum magneticum, which is a bacterium that is sensitive to the Earth's magnetic field. Using genetic engineering, the team induced another bacterium- Escherichia coli, to manufacture the bulk of this protein.
• The researchers imprinted a block of gold with a microscopic chessboard pattern of chemicals. Then they dipped the gold into a solution containing the protein and allowed it to bind to the squares, and put the entire composition in a heated solution of iron salts. After examining the results with a microscope, they discovered that the groups of magnetite grains had materialized on the treated squares, which were put into place by the bacterial protein.
• The grains of magnetite are not yet magnetically strong enough to make a useful memory card that could be placed in a real computer. 
• The advantage of the process is that growing the cards would not be as laborious as constructing a fab, which is where the process of microchip fabrication takes place. "Growing" a chip is essentially easier than making one. 

• In my opinion, I think that the idea of growing memory cards using bacterial protein is an innovative concept. It could potentially be less expensive, more efficient, and less time consuming than the standard process of creating a microchip, which could benefit the economy immensely. 

http://www.economist.com/node/21555873

day 3 week 1

#1 ISBS 


1. A physical property is a property that can be observed and measure without changing the chemical makeup of the substance. 


2. Three physical properties of water are density, melting point, and freezing point.


3. Solid water is less dense than liquid water. 


4. A lake is a setting where all three physical properties of water are observed. In it's solid state, a lake would be covered with a layer of ice. In it's gaseous state, the water would evaporate. In it's liquid state, a lake's water would remain liquid. 


5. Heterogeneous and homogeneous mixtures are different because a heterogeneous mixture is not the same throughout, whereas a homogeneous mixture is the same throughout. 


6. In order for liquid to be on top of a gasoline/liquid mixture, you would need to know the density of that liquid. 


7. a-  suspension b- suspension c- solution d- solution e- solution f- colloid 


8. The air in the room would be a colloid because it exhibits the Tyndall effect. 


9.

10. This mixture would be a suspension because the solid particles are large enough to shift to the bottom over time. 


11. A substance is an element or compound that has a uniform and definite composition. Two examples are water and salt. 


12. a- CO is a compound  b- Co is a compound  c- HCI is a compound  d- Mg is a compound   e- NaHCO3 is a compound  f- I2 is an element

B.1-B.4 vocabulary

·      Physical property- properties that can be observed and measured without changing the chemical makeup of the substance

·      Matter- anything that occupies space and has mass

·      Density- the mass of material within a given volume

·      Freezing point- 0 degrees C

·      Aqueous solution- a water based solution

·      Surface tension- the tension of the surface of a liquid caused by the attraction of the particles in the surface layer of the bulk of the liquid

·      Melting point- the temperature in which a solid will melt

·      Boiling point- the temperature in which a liquid boils

·      Suspension- a heterogeneous mixture is called a suspension if the solid particles are large enough to settle out or can be separated by using filtration

·      Mixture- when two or more substances combine and yet the substances retain their individual properties, the result is called a mixture

·      Heterogeneous mixture- when a mixture’s composition is not the same throughout

·      Tyndall effect- scattering of light, indicating that small particles still remained in the water

·      Colloid- a mixture where the Tyndall effect is present

·      Homogenous mixture- a mixture that is uniform throughout

·      Solution- all solutions of homogenous mixtures

·      Solute- the dissolved substance

·      Solvent- the dissolving agent

·      Matter chart- a flowchart of the various types of mixtures and substances

·      Particulate level- the level of water’s molecules and atoms

·      Atoms- building blocks of matter

·      Element- matter that is made up of only one kind of atom

·      Compound- a substance that is composed of the atoms of multiple elements linked together

·      Chemical formula- a formula in which compounds and elements are represented in

·      Substance- an element and compound that has a uniform and definite composition

·      Molecule- the smallest unit of a molecular compound that retains the properties of that substance

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