Monday, December 13, 2010

Ions Are Everywhere!

Nature's Recipe
Lamb & Rice Recipe
     Cuts in Gravy

Ionic Compounds:
1. calcium carbonate

2. potassium chloride

3. zinc oxide
4. copper sulfate
a)copper (I) sulfate:

b)copper (II) sulfate: 

5. manganous oxide

6. calcium iodate

7. sodium selenite

8. salt

9. ferrous sulfate

10. water

Here is a link to my partner's, Cate, blog:

Thursday, November 11, 2010

Chem Mid-Term Reveiw

2.The following length measurements were taken by students using several different measuring devices. Find the average of the measurements. Make sure that your answer has the correct number of sig figs. 10.05 cm, 10.1 cm,9.741cm, 10.6 cm, 10.5 cm. If the actual length were known to be 10.00, what would the percent error be?(Again be mindful of sig figs).

10.05 + 10.1 + 9.741 + 10.6 + 10.9 = 50.991 = 51.0

51.0 / 5 = 10. 2

(A.V. - E.V.) / A.V. x 100

(10 - 10.2) / 10 x 100

.2 / 10 x 100 

.02 x 100 


*** To find the percent error the parenthesis should really be absolute value bars.

Thursday, September 9, 2010

Physical and Chemical Properties

The household item I selected to experiment on was a marshmallow. Marshmallows seemed like an interesting choose, how would a common household react with common household items/ activities. Well after doing all of the experiments I found out that marshmallows are tougher than they appear. I noticed that it was much faster for physical changes to take place and those tended to give more conclusive results of what happened and why. But the chemical changes were much more dramatic. Using my chemistry knowledge  I was able to conclude simple things like what change was made(chemical or physical), what was the change, was there a reaction, what kind of reaction?

Stretch- Stretching out the marshmallow changed the dimensions from 3 by 3 cm to 4 by 4 cm. Proving that the marshmallow is malleable.
Freeze- After freezing the marshmallow for 30 minutes the only physical change was that it became harder, more ridged and smoother.
Boil- placing the marshmallow in 2 cups of boiling water it dissolved in matter of seconds, changing the color of the water to a murky white. The marshmallow changed state from a solid to a liquid.
Cut-No chemical changes took place I cut the marshmallow in half, changing the appearance of it and the dimensions of it.
Hammer-By hammering the marshmallow I completely flattened it out changing the size of it, it went from 3 by 3 cm to 5 by 5 cm. Again the marshmallow is malleable the marshmallow is malleable.

Cutting the marshmallow                                          Dissolving the marshmallow in water

Hairspray- The marshmallow did not react chemically with the hairspray as I expected it to, I thought that the chemicals in the hairspray would burn through  the marshmallow. The harispray created physical changes with the marshmallow, making the marshmallow slimy. Using the hairspray is a lack of a chemical change and the hairspray did the exact opposite of what i thought it would do. 
Gasoline- The marshmallow did react with the gasoline, the gasoline changed the odor of the marshmallow from none to a quite strong smell of gasoline.
Muriatic Acid(pool cleaner)- After 10 minutes in 4 tablespoons of  acid the marshmallow was completely dissolved, you could tell there was a chemical change because after dissolving the marshmallow in the acid, the acid heated up.
Fire- A classic thing to do with a marshmallow...burn it. Setting fire to the marshmallow burns it, producing heat indicating a chemical change.
Drain Opener- The marshmallow dissolved in the in the drain opener and when it did the drain opener heated up, showing that a chemical change occurred

Marshmallow while in acid                                                Marshmallow after burning