This experiment will demonstrate the importance of standards in identifying unknown substances. It will encourage observations, you will make hypotheses, record data and draw conclusions from that data.
MATERIALS:-Three jars of powders, with spatulas, to be tested as standards: Jars A, B and C-Two jars of unkown powders: X1 and X2
-Three testing liquids in dropper bottles: Bottles #1, #2 and #3
-Test Tubes
-Boiling Water Bath
-Test Tube Rack
-Test Tube Holder
METHODS:You are to write a detailed description of your METHODS. You will be provided here with a generalized set of instructions that will get you started on your investigation.You will peform and discuss the investigation with your lab partners, but write up the lab on your own.A PROBLEM STATEMENT must be written for this lab. Write it after the investigation has been completed.
You are to identify the powders that make up unknowns X1 and X2. In order to do this you must identify the powders in bottles A, B and C. You will not know the names of the powders, only that they are A, B and C. They will be identified by their reactions with liquids #1, #2 and #3.
Test tubes will be used to test the powders with liquids #1, #2 and#3. The Pyrex/Kimax test tubes will need to been washed out after each test. There are test tube brushes at the back sinks.
Each of the jars of powder has a spatula attached to it by a rubber band. To avoid contaminating other samples, and getting false data, be sure you use ony the spatula on a specific bottle to remove the powder from that bottle. Be sure you replace the spatula on the same bottle after use. DON'T FORGET TO REPLACE THE SPATULA ON THE BOTTLE.
Using the spatula, put approximately 3 mm. of powders A, B and C in three separate tubes.
1. Three Pyrex/Kimax test tubes for each powder:a. Three containing powder Ab. Three containing powder B
c. Three containing powder C
Each of the powders are to be tested with liquids #1, #2 and #3.
1. Put three drops of liquid #1 in tubes A, B and C.2. Put three drops of liquid #2 into tubes A, B and C.
Pay close attention to the reaction that you get with the liquids. Describe the reaction and record it for the RESULTS section of you lab.
3. Put enough of liquid #3 into the test tubes containing Powders A, B and C to just cover the powder.
a. Place these test tubes in the boiling water bath and wait 5 minutes. Remove the tubes with a test tube holder . Place them in your test tube rack. Describe and record the results.IF YOU ARE CONFIDENT AT THIS POINT THAT YOU CAN DEFINITELY IDENTIFY POWDERS A, B AND C WITH LIQUIDS #1, #2 AND #3, THEN USE THE SAME TESTS TO DETERMINE THE CONTENTS OF BOTTLES X1 AND X2.
Before you begin the identification of Unknown X1 and X2, construct two hypotheses that predict the results of using Liquids #1, #2 and #3 on Powders A, B and C.Write your hyotheses as If...., then statements.
DO THE TESTS AND RECORD YOUR RESULTS ON A SINGLE CHART COMPARING THE RESULTS OF POWDERS A, B AND C WITH THE RESULTS OF X1 AND X2.
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FINALLY;Interpret the data presented in the results section.-A good DISCUSSION section should contain:
a. An ANALYSIS of how the results help (or do not help) answer the problem question, or support (or not support) the hypothesis.
b. An EXAMINATION of how adequate your results are in forming the conclusion.
c. COMPARISONS with the results of previous similar studies.
Once you have completed the lab, follow the outline using only the headings with an * and follow the format and descriptions for Use a work processor to write up the lab
A copy will be turned in for grading using the