Tuesday, May 4, 2010

The unpopable water balloon!

photo credit: Alexis Chierici

When me and my partner, Kaylyn Dawkins, first entered the lab to create our mini project we had no clue what to make. All we knew is that we had a balloon to work with. We decided to make an unbreakable water balloon. we filled up the balloon and then found thing we could surround the balloon with to keep the plastic balloon itself from being harmed. We surround the water balloon with the following items

1. pink post it's (for color and/or decoration).
2. plastic tape for protection.
3. bubble rap for support.

when we finished making our balloon we went outside to test it's durability. my partner threw it up and unfortunately it popped. we failed but with more protection or balloon would have survived.

SCIENCE:
molecular structure of water and air.


a real unbreakable water balloon!

Wednesday, April 21, 2010

IProposeWe Make a mentos bottle rocket




Materials

- 2 liters of diet coke

- 4 mint flavored mentos



Procedure

1. gather the materials you will need

2. cut a strip of paper about 4 inches

3. take out 5-7 mentos out of the roll

4. Lay the Mentos face-down onto the strip of tape, just as they are lined up in a roll of Mentos.

5. Take another strip of tape the same size as the previous one, and put this one on the top. Leave the sides of the Mentos exposed

6. Take a strip of tape about three inches and roll its sticky side out around your finger to make a roll that is sticky on the outside.

7. Take that and stick it to the top of the Mentos roll

8. Stick that to the bottom of the diet coke cap

9. Make sure that it is secure and then twist the cap back on

10. 10Take the coke and face the cap opposite of where the coke should go. Jump in the air and slam the coke on the ground evenly on its side.

11. STEP BACK AND ENJOY!!!!!





Safty Precautions

- make sure you are outside when you preform the expiriment in a large open area.

- make sure there aren't a lot of people around.







Scientific Principle

*When the mentos are dropped in the bottle of Diet Coke, a large amount of carbon dioxide gas is released in an instant, resulting in an eruption of soda. Diet Coke is supersaturated with carbon dioxide gas. Scratches on the surface of a Mentos mint can serve as nucleation sites, places where the carbon dioxide gas can form bubbles. Since there are so many of these sites on a Mentos, the gas comes out of solution extremely rapidly. The effect is magnified by the fact that a Mentos is denser than Coke. As it sinks, it comes into contact with liquid from the top to the bottom of the bottle. The sudden increase in pressure that results from the rapid release of gas forces the soda out of the bottle.



SEE FOR YOURSELF!



LINK #1



LEARRRRRRRRRRRRRN MOREEEEEEEEEE :)

Thursday, March 25, 2010

Endothermic reactions





Endothermic reactions draw heat in from their surroundings




*gain heat

*have a positive delta H

*have energy as a reactant

*ex: photosynthsis


reactants + energy ---> products






Le Chatelier's principle


" If a system at equilibrium is disturbed, the system shifts to counter
the effect of the disturbance"
Pressure and Le Chatelier's Principle
count the number of gas molecules on each side of the balanced chemical equation.
* a shift towards more gas molecules INCREASES pressure.
*a shift towards fewer gas molecules DECREASES pressure.
remember: if the numbers of gas molecules is equal, then changes in pressure has no effect.

Calorimetry & Q=mcDELTA T





In one of our past units we learned about calorimetry. calorimetry is the measurement of heat flow.


the measurements are made inside an insulated apparatus called a calorimeter.


to calculate heat energy we used this formula Q=mcdeltaT.


m= the mass of the matter being measured.

c=specific heat. the amount of heat energy required to raise 1g of a substance to 1*c. (cal/g*c or J/g*c)


remeber Q=mcdeltaT can only refer to ONE object


swich up the formula to find certin variables---->


Q=mcdeltaT

m=Q/cdelatT

c= Q/mdeltaT

delta T=Q/mc



lean more about Q=mcDELTA T ***

Wednesday, March 24, 2010

DAVID WEB!









today in class we had two visitors, David Webb and his assistant. When i first walked in i noticed a bunch of random things over it the lab. everything from coca cola bottles and weights to balloons. through the class David Webb picked voulenteers form out class and had them participate in his labs. all the labs had something to do with the atmosphere. in a lot of his expiriments he used a vacuum. not a vacuum used to clean your house but a chemistry vacuum. the vacuums showed us how objects act in different atmospheres with different air pressures. i thought it was really cool to learn about how things happen in space and why humans wouldnt be able to live there. Overall it was probally one of the coolest days in chemistry.


Thursday, March 11, 2010

exothermic reactions :)




Exothermic reactions are reaction give heat off to their surroundings. the energy needed for the reaction to occur is less than the total energy released


*release heat
*have a negative delta H
*and have energy as a product
*ex: combustion

reactants → products + energy