Periodic Table Lab

Determination of the Periodic Properties of the Elements

Introduction :

Periodic Table shows the properties of elements are periodic functions of their atomic numbers. The periodic table contains alkali metals, alkaline earth metals, transition metal, basic metal, semimetal, non-metal, halogen, noble gases, lanthanides and actinides. The periodic table is important because it is organized to provide a lot of information about elements and how they relate to each other in one easy-to-use reference. It appears in nearly every science lecture room and labs because it is important for science subjects. The periodic table serves a useful purpose. The horizontal rows on the periodic table are the periods. The vertical columns on the periodic table

To prepare an activity series of the metals based on the observations from the above reactions.

Apparatus :

Spatula, Test tube, 150ml beaker

Materials :

Magnesium ribbon, phenolphthalein indicator, 6M HCl, Gra

Procedure :

The Group 2A Elements : Alkaline Earth Metals-Magnesium and Calcium

1.

A piece of magnesium ribbon was acquired. A test tube is filled up with 5ml of water. A few drops of phenolphthalein indicator is added into the test tube that was filled with 5ml of water. The magnesium ribbon was placed into the test tube. The observations were recorded.

2.

The experiment was repeated with small particles of calcium with water.(It is required to break calcium into smaller pieces.) The observations were recorded.

Mg(s) + 2H2O(aq) → Mg(OH)2(aq) + H2(aq)

Ca(s) + 2H2O(aq) → Ca(OH)2(aq) + H2(aq)

3.

Two test tubes were filled with 3ml of 6M HCl respectively. A piece of magnesium ribbon is dropped into one test tube and small pieces of calcium is dropped in the other test tube. The mouth of the test tubes is covered by the thumb once both the magnesium ribbon and small pieces of calcium is dropped into the test

Zinc Effervescence Zn+2H^+→ Zn^(2+)+ H_2

Discussion :

Group 2A Elements

Part 1 . Reactions with water

Based on the observation, both magnesium and calcium that were placed in the water turns the solution into pink. The water turns pink because of the presence of the phenolphthalein indicator. Phenolphthalein turns pink in alkaline solution and is colourless in acidic solution. Due to the hydroxide ions, both solutions turn pink and become effervescing with hydrogen gas. Below are the equations of the reactions :

Mg(s) + 2H2O(aq) → Mg(OH)2(aq) + H2(aq)

Ca(s) + 2H2O(aq) → Ca(OH)2(aq) + H2(aq)

Calcium is more reactive than Magnesium. Therefore, Ca(OH)2 changes to pink faster than Mg(OH)2 because Calcium is located below Magnesium in the periodic table. Calcium donates electrons faster than Magnesium.

Part 2 . Reactions with HCl

Both magnesium and calcium were repeated placing in 3 ml of 6M HCl. Both solution released colourless gas bubble after placing the metals in the test tubes. Both solutions were tested with burning wooden splinter placing near to the mouth of the test tubes, both of the test tubes produced a ‘pop’ sound. Below are the equations of the reactions