Magnesium Ribbon Experiment

The people in this experiment were Ashley Hoffman (that's me!), Liz Bonnett, and Gabbie Morgan.  This experiment was done sometime last week.

Materials:
~Goggles
~Crucible
~Three 3 cm Mg ribbons
~Ruler
~Electric Balance
~Bunson Burner
~Test tube stand with no test tube
~Holder to connect to stand
~Triangle thing to put crucible on
~Gas
~Gas knob and spout
~Tube to connect gas spout to bunson burner
~Tong-like things
~Matches

Procedure:
Mass three 3 cm long Mg ribbons.  Set everything up then light a match above the bunson burner, turn the gas knob a quarter of the way.  Hold the ribbon with the tong-like things and hold the Mg over the fire (don't look at it directly).  Once a bright light is formed put the Mg in the crucible and turn off the gas.  Repeat the process two more times, the only difference would be to turn the knob half way the 2nd time and three quaters of the way the 3rd time.  For each trial record the amount of time it took the Mg to light on fire from the point it was put in the fire to the point the bright light shows.

Problem:  What is the best way to ignite magnesium ribbon?  The purpose of this experiment was to find the best way to ignite magnesium ribbon.

The independent variable was the amount of gas used to light on fire through the bunson burner.  The gas knob was turned one quater of the way for the 1st experiment, half way turned the 2nd time, and three quaters of the way turned the 3rd time.

The dependent variable was time, specifically the amount of time it took to ignite the magnesium ribbon in seconds.

The controls of the experiment were how long the Mg ribbon was (3cm), the tong-like thing that was used to hold the Mg ribbon, the hight of the crucible above the bunson burner, the placement of the bunson burner beneath the crucible, the type of gas used, and the way of lighting the gas (with matches).

The quantitative data is:
~Experiment 1:  It took 11.0 seconds to ignite.  Mass of Mg ribbon before burning was .05 g.
~Experiment 2:  It took 7.0 seconds to ignite.  Mass of Mg ribbon before burning was .04 g.
~Experiment 3:  It took 5.0 seconds to ignite.  Mass of Mg ribbon before burning was .05 g.
~~Length of each Mg ribbon before igniting was 3 cm.

The qualitative data is:

~Bright white light.
~Once in crucible it looked steamy and yellowish.

~Before igniting the Mg ribbon was silver and shiny.

~After igniting the Mg ribbon was white and rough looking.

Questions:

2.  What kind of energy was released by the reaction?  What can you conclude about the product of this reaction?

   ~The types of energy released were heat and light energy.  The product of the reaction was different than the original Mg going into the experiement.  The Mg most likely combined with elements in the air.

3.  How do you know that the magnesium metal reacts with certain components of the air?

    ~Before being in high temperature the Mg was not reacting to the components in the air, yet when put in high temperature it was obvious that the Mg was reacting with something in the air due to the bright light formed.

4.  Magnesium reacts with both oxygen and nitrogen from the air at high temperature of the crucible.  Predict the chemical formulas for both products.  Write the names of these two compounds.

    ~MgO and Mg3N2. Magnesium Oxide and Magnisium Nitride.

5.  The product formed from magnesium and oxygen is white, and the product formed from magnesium and nitrogen is yellow.  From your observations, which compound makes up most of the product?

    ~Magnesium Oxide makes up most of the product because the bright white light was much larger and lasted a lot longer than the little bit of yellow.

Gas Laws!

Gas can be affected by pressure, temperature, and volume. Here are some laws describing the different relationships:

Charles' Law - The pressure is kept constant; the temperature and the volume are directly related.  When the temperature goes up so does the volume, when temperature goes down the volume goes down.

~An example of Charles' Law that we did in class is when Mrs. Sorensen placed balloons in a tub of liquid nitrogen.  As each balloon went into the tub the temperature of the gas went down and the volume went down as the gas condensed.  The pressure was kept constant throughout the entire demo.  Many balloons were allowed to be placed in the tub due to Charles' Law.  When the balloons were taken out the temperature increased and the volume of the gas increased which again demonstrated Charles' Law.
~A real-world example of Charles' Law is when someone puts a cheap waterbottle (like a Great Value waterbottle) that is filled part way up in the fridge for a couple of days.  The waterbottle will be dented when it is checked.  The reason for this is thte pressure in the fridge is kept constant while the temperature of the gas decreases while in the fridge (because it's cold in there) and the volume of the gas will decrease as well.

Boyle's Law - The temperature is kept constant; the pressure and volume are inversely related.  If the pressure goes up then the volume goes down. If the pressure goes down then the volume goes up.
~An example of Boyle's Law that we did in class is when we put a marshmallow inside a syringe, plugged the syringe, then pushed down.  By pushing down we incerased the pressure on the gas inside the syrenge and decreased the volume.  When we did this the marshmallow shrunk.  We drew a face on the marshmallow which shrunk as well.  The temperature never changed throughout the experiment.
~A real-world example of Boyle's Law is when someone pops a balloon by squeezing it.  When the balloon is being squeezed the volume is decreasing yet the pressure is increasing.  This results in the balloon popping.

Gay-Lusaac's Law - The volume is kept constant; the temperature and pressure are directly related.  When the temperature increases the pressure increases.  When the temperature decreases the pressure decreases.
~An example of Gay-Lusaac's Law that we did in class is when we hooked up a bottle to this one machine (I don't really know what the machine was).  Inside the bottle was a type of thermometer.  What the machine did was increase the pressure inside the bottle.  We turned off the machine after the pressure hit 40 psi.  After we unhooked the machine from the sealed bottle we would release the pressure slightly every few seconds and read the thermometer every time pressure was released.  What my data says is everytime pressure went down, so did the temperature.
~A real-world example of Gay-Lusaac's law is when someone uses a pressure cooker.  The volume of the gas stays the same while whatever is inside the pressure cooker cooks.  The food can cook because the increase in pressure causes an increase in temperature.  The increase in temperature allows the food to cook.

Cartesian Divers Experiment

Todays date is August 31, 2012. This experiment was done last week. My name is Ashley. The other people in the group are Liz and Gabbie. A hypothesis was not needed for this lab. The purpose of this lab was to try to get five pipets to sink and then come back up (float) in a certain order. (12345, 54321).



The independent variable is the mass added to the pipet. The dependent variable is the rate the pipets sink/float in the water. The pipets float because their density is less than one. In order to make the pipets sink pressure has to be created. In order for them to float the pressure has to be released.



The materials used in this lab were water, five pipets, a 2-liter bottle, five different sized washers, and tape. Make sure the bottle has a cap. There were no safety concerns with this lab. The first step is to take the bottle and fill it with water, the more water in the bottle the easier the lab will be. Next fill up the pipets with water about 3/4ths of the way up. After that tape a washer on each pipet then put them in the bottle. Once they are all in put the cap on tightly and apply pressure by squeezing the bottle. The more pressure appplied, the faster the pipets will sink. Then release the pressure and the pipets will come floating back up. When they go down and come back up it should be in the 12345, 54321 order.
Here is a diagram of the experiment.

In conclusion, the purpose of the experiment was to make the pipets sink and then float in a specific order. The pipets could float when just sitting in the water because they have less density than water. Water has a density of 1gram/mL. The pipets could sink when the bottle was squeezed becuase the pressure pushed more water into the pipets causing them to be denser than the water. The pipets sunk at different rates because mass of the different sized washers caused all of the pipets to have a different density. Another way to change the rate the pipets sink is by changing the amount of pressure applied, the more pressure the faster they sink. This experiment worked because of Pascal's principle which states that the pressure applied to a fluid spreads throughout the entire fluid. Another thing that works because of Pascal's principle is a hydrolic car lift. A few errors were made in this lab. Some errors in the lab included putting too much water in the pipets which caused them to sink when put in the bottle, poking the bottle to make the pipets sink, shaking the bottle to make the pipets sink, not putting enough tape on the washers and having them fall off in the bottle, and putting too little water into the bottle. Without a lot of water it is harder to make the pipets sink. To improve the experiment I recommend putting in enough water to almost completely fill the bottle.