Practical: Investigate Metals Reacting with Acids (Edexcel IGCSE Chemistry: Double Science)

Aim

To investigate the reactions between dilute hydrochloric and sulfuric acids with the metals magnesium, iron and zinc

Diagram

Mg, Fe and Zn reacting with acid

Investigating the reactions of dilute acids with metals

Method

1. Wear some safety glasses before handling acids
2. Using a small measuring cylinder, add 5 cm³ of dilute hydrochloric acid to each of three test tubes
3. Add about 1 cm length of magnesium ribbon to the first tube, observe and note down what you see
4. Use a lighted splint to test for any gases given off
5. To the second test tube add a few pieces of iron filings and to the third some zinc turnings
6. Observe what happens, test for any gases and note down your observations
7. Repeat the experiment with dilute sulfuric acid

Results

Metals with Acids Observations Table

Metal	With dilute hydrochloric acid	With dilute sulfuric acid
Magnesium	Dissolves quickly, gets hot, gas given off which goes pop with a lighted splint, colourless solution left	Rapid bubbling, splint goes pop, metal dissolves
Iron	Very slow bubbling	Slow reaction, small bubbles seen
Zinc	Bubbles given off, metal slowly dissolves	Metal dissolves forming colourless solution, gas given off slowly

Table of acid-metal reactions

Metal	Sulfuric acid	Hydrochloric acid
Magnesium	Mg (s) + H2SO4 (aq) → MgSO4 (aq) + H2 (g)	Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g)
Zinc	Zn (s) + H2SO4 (aq) → ZnSO4 (aq) + H2 (g)	Zn (s) + 2HCl (aq) → ZnCl2 (aq) + H2 (g)
Iron	Fe (s) + H2SO4 (aq) → FeSO4 (aq) + H2 (g)	Fe (s) + 2HCl (aq) → FeCl2 (aq) + H2 (g)

Conclusion

• The metals can be ranked in reactivity order Mg > Zn > Fe
• The three metals react in the same with both acids
• Hydrogen and a metal salt solution is produced