Displacement of copper by zinc

Objectives

• Show that a more reactive metal displaces a less reactive one from its salt.
• Measure the temperature change of an exothermic reaction.

Theory

Zinc is more reactive than copper. It loses electrons more readily, so zinc atoms go into solution as Zn²⁺ ions while Cu²⁺ ions are deposited as copper metal. The blue colour of the solution is due to Cu²⁺, so it fades as the reaction proceeds.

Zn + CuSO₄ → ZnSO₄ + Cu

Procedure

1. Put on your safety goggles and lab coat.
2. Place a beaker and add about 50 mL of copper(II) sulfate solution.
3. Place a thermometer and record the starting temperature.
4. Add about 3 g of zinc granules.
5. Watch the colour of the solution change.
6. Record the temperature again after the colour has faded.

Precautions

• Copper(II) sulfate is harmful. Wash your hands afterwards.

Subject

Chemistry

Grade

9–10

Chapter

Metals (Nepal National Curriculum (CDC), grade 10)

Difficulty

Easy

Duration

15 min

Safety level

Low

Version

1.0

Apparatus

• Beaker (250 mL)
• Thermometer

Chemicals

• Copper(II) sulfate solution CuSO₄ Harmful
• Zinc granules Zn