Detecting Signs of Chemical Change

Detecting Signs of Chemical Change

REAC 399

Prepared by: Elizabeth G. Perez

Date of experiment: October 3, 2006

Course: Chemistry 100/60

Abstract:

The objective of this experiment will be to combine various substances, liquids and metals, and to observe their behavior when they are combined. The types of reactions observed shall determine the nature of these reactions: physical or chemical.

Introduction:

An elementsÐŽ¦ reaction to certain substances may be predicted by its placement on the Periodic Table of Elements. Across a period, an element on the left will react with more vigor than one on the right, of the same period. Vertically, as elements are sectioned into groups, the reaction of each element increases as you move down in the same group. With this in mind, the reactions of the substances involved in this experiment may be hypothesized, observed, and validated.

Material and equipment:

„X 12 test tubes

„X 10-mL graduated cylinder

„X Water ÐŽV deionizer (distilled water)

„X 0.1M cobalt (II) chloride hexahydrate

„X 95% ethanol

„X 0.1M cobalt (II) chloride hexahydrate dissolved in 95% ethanol

„X zinc

„X 1M hydrochloric acid solution

„X 0.1M copper (II) sulfate solution

„X 0.5M sodium hydrogen carbonate solution

„X 1M ammonia solution

„X magnesium

„X 1M sodium hydroxide solution

„X ammonium chloride

Procedure:

A. Be sure to always start with clean, dry test tubes, equipment, and tools.

B. Put a label on each test tube. With a pencil, number each test tube from one to twelve.

C. For this experiment, you will add the measured amount of the first sample to the measured amount of the second sample into its respectively labeled test tube then observe if a reaction occurs. In your Data Table, record the samples added to each test tube, describe the reaction observed, if any, and whether or not a chemical reaction took place.

D. Put on your safety glasses and letÐŽ¦s begin:

1. Put the amount of 0.1M cobalt (II) chloride hexahydrate that fills the end of a spatula into a test tube. Then add 2mL of 95% ethanol. Tap the end of the test tube to mix the solution and record the pertinent data in section 1 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

2. Put 1mL of 0.1M cobalt (II) chloride hexahydrate dissolved in 95% ethanol into a test tube. Then add 1mL of deionized water. Tap the end of the test tube to mix the solution and record the pertinent data in section 2 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

3. Put a sample of zinc into a test tube. Then add 2mL of 1M hydrochloric acid solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 3 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

4. Put a sample of zinc into a test tube. Then add 2mL 0.1M copper (II)

sulfate solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 4 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

5. Put 1mL of 0.1M copper (II) sulfate solution into a test tube. Then add 1mL of 1M hydrochloric acid solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 5 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

6. Put 1mL of 0.1M copper (II) sulfate solution into a test tube. Then add 1mL of 0.5M sodium hydrogen carbonate solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 6 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

7. Put 1mL of 0.1M copper (II) sulfate solution into a test tube. Then add 1mL of 1M ammonia solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 7 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

8. Put a 1cm strip of magnesium into a test tube. Then add 2mL of 0.1M copper (II) sulfate solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 8 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

9. Put a 1cm strip of magnesium into a test tube. Then add 2mL of 1M hydrochloric acid solution. Tap the end of the test tube to mix the solution and record the pertinent data in section 9 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor.

10. Put 1mL of 1M hydrochloric acid solution into a test tube. Then add 1mL of 1M sodium hydroxide solution. Tap the end of the test tube to mix