Reactivity of metals
Aim: To compare the reactivity of various metals by observing their reaction with hydrochloric acid
Hypothesis:
Variables: dependent/ independent
Materials: * 2 M hydrochloric acid * Detergent * Test tubes and test tube rack * 0.5cm pieces of magnesium, aluminum, iron, zinc and copper * Steel wool * Ruler * Timer * Bench Mat
Procedure: see page 233 of exercise book
Results: Metal | Observations | Height of foam (cm) | Magnesium | Fast foaming, whole magnesium piece was covered | 1.8cm | Aluminum | Started to create floaties then became a misty colour but no foam | 1cm of liquid but no foam | Iron | Instantly became a milky colour but no foam | 1cm of liquid but no foam | Zinc | Very white colour no foam | 1cm of liquid but no foam | Copper | Yellowy colour and milky | 1cm of liquid but no foam |
Discussion: 1. Magnesium was most reactive 2. Iron was least reactive 3. The metals were cleaned with steel wool first to remove and rust/ dirt which might cause the reaction to vary 4. Detergent was added to the test tube because 5. Magnesium might also produce an increase in fire when lit 6. Magnesium is in the group alkaline metals and has 2 valence electrons. Alkaline metals have a low melting point and are relatively soft and very reactive. Alkaline metals react with water producing a hydrogen gas and alkaline solution. That is why it foamed up so much. And also the further down you go in a group the more reactive the element will be.