Group IIA: The Alkaline Earth Metals
The representative elements from this group that we are using in this lab are magnesium and calcium. Locate them on the Periodic Table.
1. Reaction of Alkaline Earth Metals with Water.
Magnesium-Clean a small piece of magnesium ribbon with steel wool. Place about 5 mL of distilled water and 1 drop of phenolphthalein indicator solution in a test tube. Drop in the magnesium ribbon and observe carefully to see a reaction. Note the change in color of the indicator. (Recall from previous learning what this color change tells you about the identity of one of your products.) After several minutes, heat the test tube with a Bunsen burner (do not boil) to speed up the reaction. Record all observations. Pour the contents of the test tube in the sink, but use tweezers to recover the ribbon to use for future experimentation. Dry and save.
Calcium-Repeat the above procedure using a small piece of calcium. There is no need to heat up the mixture as you did above. To identify the gaseous product of the reaction, light a wood splint and place in the test tube. Record all your observations. Pour the contents of the test tube in the sink (most likely there will not be enough calcium to recover).
Group IA: The Alkali Metals
The representative elements from this group that we are using in this lab are lithium, sodium and potassium each of which is stored in kerosene. Locate them on the Periodic Table. Handle these only with forceps. Blot the excess kerosene from the metal with paper towel. In the following experiments always keep the beaker at arm’s length. Collect small pieces of each of metals and place them on a paper towel. Keep track of which metal is which.
1. Reactivity of Alkali Metals with Water.
Put approximately 50 mL of distilled water in a 250 mL beaker. Add 1 drop of phenolphthalein indicator solution to the beaker. Drop a small piece of sodium metal into the beaker and immediately cover the top of the beaker with wire gauze. (The gaseous product is hydrogen gas, but for various reasons the flame test will not work to test for it.) Record all of your observations. Add any remaining pieces of sodium metal to the beaker. Pour the contents of the beaker in the sink and rinse well with water.
Return all lab materials to their appropriate locations, dispose of paper towels and clean off your desk.