Friday, November 5, 2010

:: Introduction To Chemical Reactions::

INTRODUCTION:

What is the purpose of this lab you may ask?  Well the purpose of this lab is to make qualitative and quantitative observations about physical and chemical changes during a chemical reaction.When you do this lab, you will see the chemical indicators that happen when there is a chemical change in an experiment, while having fun at the same time. Well....if you like chemistry you will enjoy this!! =)


MATERIALS:
  • Beaker (150 or 25
  • Copper (II) Sulfate Pentahydrate - caution, toxic substance - Use scoopula
  • 100 mL graduated cylinder
  • Stirring Rod
  • Thermometer 
  • Square Foil of Aluminum Foil

SAFETY ITEMS:
  • Goggles
  • Apron 
PROCEDURE:
  • Add water to a beaker. ( Amount doesn't matter just between 75 and 100 ml.)
  • Using the scoopula, add Copper Sulfate Pentahydrate to the beaker with water. (Amount doesn't matter either.)
  • Using the stirring rod, stir the water and copper sulfate pentahydrate until the solid is dissolved. 
  • Take the aluminum foil, roll it into a loose ball and add it to the solution. Stir it with the stirring rod for 15 sec. 
  • Take a CLEAN scoopula and add sodium Chloride to the beaker. Stir until the NaCl is dissolved. 
  • After the lab is done, safely remove the chemical. (Do not pour down sink and don't it to your skin!)
  • Wash the beaker with soap and water, and safely store the material. 
 Conclusion:
During different parts of the lab we were asked to make several observations, which are:
  • After we added the water, we had to make 1 qualitative and 2 quantitative observations: 1) It is wet,  2) It is clear,  3) It is a liquid   ( Real Scientific!!!!!!!!!!)
  • After we added the sodium sulfate pentahydrate, we had to tell if it was homo-or hetero-geneous and explain why: It was homogeneous because the liquid mixture was uniform throughout. 
  • After adding the foil, we had to make one quantitative observation, which was: the color became darker. Did a chemical change occur? Yes, color change, the color became a darker blue. 
  • After adding the the sodium chloride the mixture became heterogeneous because red solid began to appear. 
  • It meant a physical change
  • What was the red dots? It was the copper that had seperated!
After completing this lab, we have observed a chemical reaction between copper ion and aluminum, which produced copper metal, hydrogen gas, and aluminum ions.