Introduction to the Chemical Laboratory

Purpose: 
To learn to make qualitative and quantitative observations.
To see the difference between physical and chemical changes during a chemical reaction.
Materials:

• beaker
• copper sulfate pentahydrate- CAUTION, toxic substance
• scoopula
• 100 ml graduated cylinder
• stirring rod
• thermometer
• small square of aluminum foil

Procedures/Observations:

1. Fill the beaker with 75-100 ml of water.
• We observed that there was 80 ml of water in our beaker at 22 degrees Celsius.  Our liquid was clear.
2. We added some copper sulfate pentahydrate.  The measurement is unimportant, but we added about 1/4 of the scoopula.
3. Then, we stirred the copper sulfate pentahydrate in the water until it dissolved completely.
• This turned the water a blue color.
4. We, then crumpled up a small square of aluminum foil into a loose ball.
• No reaction or anything happened to the blue water.
• This is an example of a Homogeneous solution because it looks like one mixture.
5. We added a good scoop of Sodium to the blue water with aluminum foil.
• This is when a chemical reaction occured. 
•  The water started to turn gray and cloudy.
• The temperature rose to 46.8 degrees Celsius.
• The aluminum foil fell apart and became brown and rusty in spots.  
• This is an example of a heterogeneous solution because you can see more than one mixture throughout the solution.

This is a side view of the chemical reaction (above)

This is over the top of the reaction (below)

 

Clean Up

1. After about 10 minutes take you beaker over to the large funnel and beaker and slowly pour your mixture into the beaker.
2. Then clean you beaker with soup and tap water.
3. Rinse with distilled water. 
4. Make sure your lab station is clean and all you materials are put away in their proper location.

Conclusion

When you have water and copper sulfate pentahydrate then you have a chemical change.  The color changes which is an indicator of a chemical change.  When you add aluminum foil to that then nothing happens but then when you add sodium a chemical reaction happens.  You can see the copper floating around and the aluminum foil breaks into small pieces.  This was interesting to watch.