Solutions, Colloids, and Suspensions

Solutions, Colloids, and Suspensions are all types of mixtures, but there are important differences between the three.
Solutions are transparent; some might have a color, but you should still be able to see through them. A solution will not separate if left alone for a long period of time, and cannot be separated by normal filtration either. The particles have dimensions between 0.1 to 2 nanometers.

Colloids are mixtures as well. The particles that are in a colloid are usually larger clumps of molecules, which have dimensions between 2 to 1000 nanometers. The colloid is similar a solution in that it is homogeneous and isn't separated by filtration or when left alone. However, colloids are create a murky solution because the particles are large enough to disrupt light.

Suspensions contain the largest particles of the three, each particle being over 1000 nanometers. Suspensions separate on standing and will also separate by filtration. The particles are visible in suspensions much of the time.
Examples)
Solution --> Rubbing Alcohol (certain percentage alcohol, like 70%)
Colloid --> Ink, Paint
Suspension --> Oil in Water, Dust in Air

Gas Simulation Conclusion

After testing the pressure in the simulator for the same amounts of heavy and light molecules (115, 230, 345, and 460), I generally found that the lighter molecules created less pressure. This could be because pressure is a measurement of the collision force, and the greater the mass of an object, the greater the force exerted by it. One thing that I found strange was that at 115 molecules, the pressure was approximately the same (.59 for heavy, and .6 for light). However, there might be a flaw in my data because the pressure varied constantly on the reader, as the molecules bounced around within the chamber.

Chemistry in Action Homework

Reaction 1a:   MnCl₂ + 2NaOH → Mn (OH)₂ + 2NaCl

Reaction 1b:  O₂ + 2Mn (OH)₂ → 2MnO(OH)₂

Reaction 2:    MnO (OH)₂ +H₂SO₄ + 2NaI → Mn(OH)₂ + NaSO₄ + H₂O + I₂

Reaction 3:      I₂ +   2Na₂S₂O₃    à   Na₂S₄O₆  +   2NaI

HOMEWORK:  You must use your blog to post the research and answers to this document. 

QUESTION 1:  

For the dissolved oxygen reactions:

What type of reaction is 1a? Reaction 1a is a Double Displacement Reaction, because one molecule from each of the reactants is switched.

What type of reaction is 1b? Reaction 1b is a Synthesis Reaction, because the reactants are joined together.

What do you think reaction 2 and 3 are?  I would guess that 2 would be a Triple Displacement Reaction, and 3 would be a Single Replacement Reaction (sort of).

QUESTION 2:

a.      What is hypoxia? Hypoxia is the lack of oxygen. This can occur to the whole organism in an oxygen-deprived environment, or to just one part of the body if there is inadequate blood circulation.

b.      When does hypoxia reach its highest levels in Long Island Sound and in the Gulf of Mexico? In coastal areas, hypoxia reaches its highest levels with a combination of dead algae and pollution.

c.      What are the causes of hypoxia? Hypoxia is caused by phosphorous and nitrogen, and we can help solve this problem by better sewage treatment, reducing the amount of pesticides and fertilizers going into the ocean, and putting more plants in the water.

d.      Research the sources of high levels of nitrate ion in water bodies. Sources of nitrogen and nitrates may include runoff or seepage from fertilized agricultural lands, animal feedlots, or municipal and industrial waste water. Other sources may include runoff from garbage dumps, septic tanks and private sewage disposal systems, and urban drainage.

e.      What are “safe levels “  of nitrate in drinking water and what are the effects on humans of drinking water with high levels of nitrate ion? Most states enforce a drinking water standard for nitrate of 10 milligrams per liter (10 mg/L); if there too much more than this amount, humans can actually also experience hypoxia.

Research:

http://toxics.usgs.gov/definitions/hypoxia.html

http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&lv=list.listByNewest&r=231335&subtop=274

http://www.idph.state.il.us/envhealth/factsheets/NitrateFS.htm

BONUS HW: What is the double replacement reaction responsible for the dissolving of marble by acid rain?

Marble is composed mainly of calcium carbonate.
Calcium Carbonate - CaCO3
The corroding element of acid rain is Sulfuric Acid
Sulfuric Acid - H2SO4
So the reactants would be CaCO3 and H2SO4
CaCO3 + H2SO4 ----> Ca + SO4 + H2O + CO2
In other words, Marble and Acid Rain react to produce calcium, sulfur oxide, water, and carbon dioxide.

Robert Cheng

 

THERMITE REACTION

Record the reaction with symbols and with words.  Make sure it is balanced.

Fe₂O₃ + 2Al → 2Fe + Al₂O₃

Iron (III) Oxide and Aluminum react to form Iron and Aluminum Oxide.

Thermite reactions create short burst of very high temperatures. It is commonly used to join railroad tracks, since the separately-shipped pieces have to be joined for trains to run smoothly. The process of using the thermite reaction to create the heat that joins two pieces of metal together is called thermite welding.

Try to find another example of a useful single replacement reaction.

Another example of a single replacement reaction is the reaction that chemically creates silver, which we learned about earlier this year.

This reactants in this case would be Zinc and Silver Nitrate and the products would be Zinc Nitrate and Silver.