Chemical Reactions Lab

Problem How can you tell if there has been a chemical reaction?

Hypothesis Form your hypothesis based on the information already given and your previous knowledge. Remember that a hypothesis is an if / then statement. If ……… then………

Test/Experiment In this lab you will be given several chemicals to put together as directed in the lab.  You will need to observe what happens when you put those things together (wait at least 1 minute after each combination)!! Conduct the experiment on the paper given, in the box. You need to list those combinations on your own paper. While doing the experiment you will need to record: Each reactant and the color of each reactant What happens when the reactants combine and/or final color and observations after the reaction.  Remember – wait at LEAST 1 FULL MINUTE for the reaction to complete.

Test/Experiment Make sure that you follow the procedures correctly. Not following directions will result in removal from this lab, a zero and a parent contact. One drop of the chemical. Do in the order they are listed on the paper. Clean up procedure: take a paper towel and carefully dab up the liquid then throw away the trash, go wash your hands and get in your seat.

Data Table A. NaHCO3 HCl B. HCl Blue dye C. Blue dye NaOCl HCl D. NaOCl KI Starch E. KI Pb(NO3)2 F. Pb(NO3)2 CaCl2 G. CaCl2 NaHSO4

Data Table Continued H. NaHSO4 Na2CO3 I. Na2CO3 Phen J. Phen NaOH K. NaOH AgNO3 L. AgNO3 NH3 M. NH3 CuSO4 N. CuSO4 NaHCO3

Test/Experiment Analysis of testing/experimenting Write an analysis statement based on your results of the experiment. Remember an analysis statement is a when/then statement. When ………… then……….

Questions When HCl is added to NaHCO3 what did you see happening? Do you know what type of bubbles were produced? This type of gas is commonly found in something we drink, what is it? Which of the other mixtures formed gases?

Questions 5. What color did the blue food dye turn when HCl was added? 6. Our bodies use HCl to help digest food, where do we keep our Hydrochloric acid? 7. What happened to the color of the blue dye when NaOCl was added to it?

Questions 8. KI and NaOCl mixed to together to make what color? 9. When starch was added to it what happened? 10.  What reaction produced a bright yellow paint looking substance? 11.  When mixing solutions and you get a solid, the solid is called a(n)____________________. 12.  Which other mixing produced precipitates?

Questions 13.  Which mixture produced a precipitate that was very slow to form? 14.  Which solutions produced a distinctive “muddy” brown precipitate? 15.  What are the evidences of a chemical change? 16.  How many of those evidences did you observe in the lab today?

Conclusion Write a conclusion.  It should be the complete story of the lab.  Remember this is your essay, and should include what you thought would happen, what you saw happen and what you learned based on your results.  Make sure to include any ‘abnormal’ activity that occurred during the experiment process. (examples – not keeping proper time, drops did not go together immediately, etc.)