Falling Ball

Research question:

How does the height of a falling ball affect the force with which it hits the flosorb?

Hypothesis:

I think that the higher the ball is, the harder it will hit the jelly because a falling object accelerates at 9.81 m/s² and the more time it has to accelerate the faster it will go (more force is going to apply to the flosorb that will be on the floor).

List of variables:

            - Independent variable: Height of the ball (10 cm, 50cm, 1m, 1.5m, 2m, 2.5m). They will be measured using a ruler.

            - Dependent variable: Depth of the mark that leaves on the jelly, measured using a ruler too.

            - Controlled variables: Air resistance (in the same room, no wind), ball mass (using the same ball all the time), ball volume (same ball), ball weight (same ball), amount of powder in the water, amount of flosorb (water+powder)

List of materials:

-          - Flosorb (powder+water)              - Beaker                   - Ball               - Ruler               - Pen and paper      

Method:

            1.- Mix 250mL of water with 7g of powder in a beaker to make the flosorb.

            2.- Drop the ball (marble) from 10cm. above the plasticene, and measure the depth of the mark it left.

3.- Repeat the same thing 3 times, and then make an average.

4.- Repeat the whole thing but with different heights (50 cm, 1m, 1.5m, 2m, 2.5m)

5.- Annotate the results in a table and then make a graph.

6.- Make a conclusion.

Table for results:

	10 cm	50 cm	1 m	1.5 m	2 m	2.5 m
Test 1
Test 2
Test 3
Average					[s4]

Collegative Properties

Pure Solvent:

The vapour pressure is caused by some molecules turning from liquid to gas and therefore causing vapour pressure.

Solution:

Solution of pure liquid and a solute that is not volutile which means that it won´t turn into a gas. Because there are now other molecules taking up the spaceon the surface, less molecules can turn to gas. So vapour pressure is lower.

graphs

Gay Lussac law.

Conclusion:  When the temperature increases, the pressure also increases and when the temperature decreases, the pressure also decreases.

The expression Gay-Lussac's law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though it is more usually applied to his law of combining volumes, the first listed here. The first law relates to volumes before and after a chemical reaction while the second concerns the pressure and temperature relationship for a sample of gas often known as Amonton´s law.

 

If the pressure increases the temperature also increase and vice versa, as we can see in the formula below.

p1/t1 = p2/t2

How to prepare a Schlenk Tube

A schlenk tube is a reaction vessel tipically used in air sensitive chemistry.

The first picture shows all the materials we need, and the second one how it should end.

Here are some videos to show how it's done:

                                          

1. First, we put vasseline in the stopcock, and we attach it with the rubber bands.
2. We put the stopper on top, and fold it so that no air can get in or out.

The Property of the Materials

Ionic compounds have such a high boiling point because they form very strong bonds and there is more energy required to break these bonds. For this reason the energy required for an ionic compound to boil is high.

Metallic bonds are very strong and for this reason a lot of energy is needed to break them. This is why metals have high melting points and boiling points.