Practical: Investigating Metals Reacting with Acids — The Reactivity Series | IGCSE Chemistry

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Displacement reactions and determining order of reactivity from experimental data.

Compare how three different metals — magnesium, zinc and iron — react with two different dilute acids (HCl and H₂SO₄), and use the observations to rank the metals by reactivity

Wear safety glasses; acids and the hydrogen produced are hazardous
Set up six labelled test tubes in a rack
Into each tube, measure 5 cm³ of one of the acids using a small measuring cylinder
Drop a small, comparable sample of metal into each tube: a 1 cm strip of magnesium ribbon, a few zinc turnings, or a few iron filings
Watch each tube for bubbling, heat change and any colour change in the solution; time how long it takes for the metal to disappear
Test any gas given off by holding a lit splint at the mouth of the tube — a hydrogen pop confirms the gas
Repeat with the second acid and record observations in the same table

Metal	With dilute HCl	With dilute H₂SO₄
Magnesium	Rapid fizzing, tube warms noticeably, metal disappears within a minute, splint pops	Rapid fizzing, tube warms, metal disappears within a minute, splint pops
Zinc	Steady stream of small bubbles, metal dissolves gradually, splint pops	Steady fizzing, metal dissolves more slowly than magnesium, splint pops
Iron	Very slow bubbling, metal almost unchanged after several minutes	Slow bubbling, only small bubbles seen

Order of reactivity from these observations: Mg > Zn > Fe
For each metal, the products with hydrochloric acid and with sulfuric acid follow the same general pattern: a soluble salt of the metal plus hydrogen gas
The order found in this practical matches the order of these metals in the standard reactivity series in section 3