CHE 142--LAB 3--Periodic Table and
Patterns of Reactivity
In today’s lab we will examine some of the elements in the periodic table. We will then
generate a couple of them and examine their behaviors. Finally, we will study the
relative reactivities of several metals, and try to evaluate their metallic character on this
basis.
Some key concepts which this lab is meant to elucidate are:
• Periodic behavior
• Metallic and non-metallic behavior
• Activity Series
• Single displacement reactions, decomposition reactions and combustion
reactions
Ongoing topics which are reviewed include:
• carbonate ion and its reactions with acids
• structure of acetic acid
• metathesis reactions
• model building
PERIODIC TABLE
Examine the elements in he Flynn box. Find their symbols and then place those
symbols in the attached chart, and write down their physical appearance in your
notebook
Where are colored elements most likely to be found?
Where are lustrous elements most likely to be found?
Metallic character supposedly increases as you go down the table and as you go to the
right--Do your observations support this?
Are there any other patterns either in appearance or in reactivity that occur to you?
For the arbor scientific element kit, examine and report on the appearance of the
halogens. Examine silicon, germanium and boron. Do they appear to be metallic? How
do the alkali and alkaline earth metals appear?
PRODUCTION AND REACTION OF SOME ELEMENTS
During these experiments, make careful note of all observations including color
changes, production of solids or gases, and temperature rises. Some experiments
require you to start a process and then let it run for awhile. We have tried to place these
experiments right at the beginning, so that you can efficiently use your lab time by
moving on to other, more rapid experiments while you are awaiting your results.
Iron
Put a large magnetic stir bar into a 400 mL beaker. Crush some Product 19 Flakes and
fill the beaker 1/3 full. Add enough water so that the beaker is half full and then start
stirring the mixture with a magnetic stirrer. Leave this going for 15-20 minutes. If the
mixture becomes too thick for the stir bar to smoothly stir it, add a little water.
When the stirring is done, carefully empty the mushy mixture into a second beaker and
then remove stir bar, placing it on a piece of towel. (DO NOT TOUCH THE BAR WITH
FORCEPS OR ANY OTHER METAL OBJECT) Examine it carefully. Clean a 400 ml
beaker and place the bar back into the beaker and then cover it with 0.1M HCl and stir.
Place some iron filings into 0.1 M HCl. Test both of these solutions with potassium
thiocyanate. This is a very sensitive test for dissolved iron.
Place some iron filings into a small beaker with some zinc nitrate in it and observe.
Copper
Into a 50 ml beaker place 20 ml of copper nitrate solution, and 5 ml of vinegar. Place
an iron nail into the beaker and let stand for 20 minutes. Remove the nail with some
forceps and comment.
Into another 50 ml beaker place 20 ml of copper nitrate solution and 5 ml of vinegar.
Place about 1/4 teaspoon of salt into the solution and then add about 1.5 square inches
of aluminum foil and set aside. Check this mixture every few minutes to see what is
happening.
Place some copper wire into a beaker containing some vinegar and note any
observations.
Oxygen
Place 15 ml of 3% solution of hydrogen peroxide into a 25 ml flask. Place a very small
amount of manganese dioxide in the solution and cover it with a small watch glass right
away.
Observe the reaction and, after about 2 minute, light a small wooden splint. Extinguish
the flame but be sure the splint is still glowing. While it is glowing, plunge it into the flask
(but not into the liquid!!!). What happens and why? What kind of reaction is taking
place?
Build models of hydrogen peroxide and the reaction products to illustrate what is going
on.
Contrast the behavior towards combustion of the peroxide reaction with this one:
Light a candle and drip some wax onto a cardboard square so that the extinguished
candle can be supported by the melted wax. Put the candle into a 1 liter beaker. Weigh
out 25 grams of sodium bicarbonate and place that in the beaker around the candle.
Light the candle and then slowly pour 5 ml of vinegar into the beaker. What happens to
the candle? If the candle goes out, try to re-light it.
When the fizzing goes out, tip the beaker to “pour out the gas”. Set it upright again , and
now try to light the candle. What is happening?
Try building a model of the bicarbonate ion and see if this helps you explain the product
that is given off when it reacts with vinegar.
Calcium
Place a small piece of calcium metal into a 100 ml beaker with 20 ml of water in it, and
place another piece of calcium into a beaker with vinegar in it and record any and all
observations
Zinc
Place a small piece of piece of zinc metal into a 100 ml beaker with 20 ml of water in it,
and place another piece of zinc into a beaker with vinegar in it.
Place zinc metal into a solution of iron sulfate.
ACTIVITY SERIES
The activity series is a way of rating how metallic an element is. The most metallic
elements are those which react most vigorously with water or with acid to generate
hydrogen gas.
In addition, the more active of a pair of elements will displace a less active element from
an ionic solution of that element. In other words the more active element will “kick out”
the less active element. The less active element will appear in its elemental form and
the less active element will disappear into solution.
You have examined various reactions involving the elements, calcium, aluminum,
copper, iron and zinc. Based on your observations, rate these elements according to
their metallic character and explain your reasoning. Then compare your results with a
published “activity series”, either in PERIODIC KINGDOM or in a chemistry text book.
REPORT
Remember to report on all three sections of today’s experiment: Periodic Table,
Production and reactions of metals, activity series.