Aluminum ions, Copper metal, Hydrogen gas... OH MY!

INTRODUCTION
The purpose of this Chemical Lab is to become familiar with the terms: qualitative, quantitative and make observations about chemical and physical changes. This lab gives us an introduction to the laboratory and makes us follow directions and respond to questions as we go along.


HYPOTHESIS:
Predicted that the aluminum foil would change color or completely disintegrate in the mixture.

MATERIALS NEEDED:

• Beaker (150 or 250 mL)
• Copper(II) Sulfate Pentahydrate - CAUTION: Toxic Substance
• Sodium Chloride
• Scoopula
• 100 mL graduated cylinder
• Stirring Rod
• Thermometer
• Small square of aluminum foil
• Apron
• Goggles

PROCEDURE:

First, make sure your not alone and form a group of two or more. Take all appropriate safety precautions, where appropriate clothing and safety goggles and safety apron. 

Get a beaker(150 or 250 ml), a 100 ml graduated cylinder, a scoopula, a thermometer, some aluminum foil, and a container holding some cupric sulfate pentahydrate. Go to the appropriate source and add some water in your beaker. The exact amount is not important, although it should be between 75 and 100 ml.

Now using your scoopula, obtain some of the copper (II) sulfate pentahydrate. Again the exact amount is unimportant, but your scoopula should be about one quarter filled with the solid. Place the CuSO4 5H2O in the beaker, and stir with the stirring rod until all the solid has dissolved.

Obtain the aluminum foil sample in front of you and crumple it into a loose ball. Place the aluminum ball into the copper (II) sulfate solution, and stir gently for about 15 sec. Write down detailed observation. 

Make sure your scoopula is clean (rinse with tap water and dry with a paper towel) and obtain a large scoop of sodium chloride from the labeled container. Add the NaCl to the beaker containing the copper(H) sulfate- aluminum mixture. Stir until all of the sodium chloride is dissolved and make detailed observations. 

After approximately 10 minutes, take your beaker over to the large funnel and beaker and slowly decant (pour) your mixture into the beaker. Then clean your beaker thoroughly with soap and tap water, and then a final rinse with distilled water. Make sure your lab station is clean, return everything to the proper place.

QUESTIONS TO ASK YOURSELF WHILE YOU PERFORM THIS EXPERIMENT:

After step 1: Make a qualitive and quantative observation of a physical property of the water. 

After step 2: The mixture you just made was CUSO4 in water. Is this mixture heterogenous or  

                      homogenous? Explain. 

After step 3: Once you added the aluminum foil, what observations can you make? What happened to 

                      the foil?

After step 4: Once you added the sodium chloride to the mixture, what happened to the foil? 

• Did you see a physical or chemical change? 
• How many states of matter do you observe? Describe, from all your observations, what they are. Which do you see in your beaker now?
• Any idea what the red solid is that has dropped to the bottom of your beaker?          

DISCUSSION/CONCLUSION: 

We just observed a chemical reaction between copper ion and aluminum, which produced copper metal, hydrogen gas, and aluminum ions. During the course of the reaction we made several different observations that were all indicators of a chemical change. Some indicators of chemical change would be: Production of bubbles with no added heat, an increase in temperature, a change in color, and a percipitate-which in this case, was copper. 

After we begun our experiment, we made a qualitative and two quantitative observations of the physical property of the water in our beaker. Qualitative: It was clear, pure water. Quantitative: There was 90 mL of water in the beaker and it had a temperature of 20.8 Degrees Celsius. 

After we added the copper(II) sulfate, we noticed we had a homogenous mixture of clear, blue, liquid. HINT: If you want the copper(II) sulfate to dissolve quicker, use hot water. 

Once we added the aluminum foil ball to the copper(II) sulfate/water mixture... absolutely nothing happened. But the temperature had gone up by about 2 Degrees Celsius. 

However; after the addition of sodium chloride, the aluminum foil changed color from silver to a reddish-black color. It also developed bubbles on the outer surface even when no heat had been added. We also saw both a physical and chemical change; Physical: The color changed. Chemical: An element had formed on the outside and had fallen to the bottom of the beaker. We also noticed all states of matter, a solid (the foil), a liquid (the blue water mixture), and gas (bubbles), and we concluded that copper was the red solid that had formed and fallen in the beaker.

INDICATORS OF A CHEMICAL CHANGE:

1. Formation of a Percipitate 
2. Color Change
3. Bubbles (without added heat)
4. Increase in Temperature

CLEAN-UP:

1. Clean your beaker well with soap and water, rinsing it last with distilled water. 
2. Make sure your lab station is clean. 
3. Return all safety equipment to its proper location.