In their lab books, under , Maya wrote the final line of the story:
“Exothermic,” Maya whispered, recording the temperature rise. The magnesium was even more reactive than zinc. It had ripped the copper from the solution with such force that it generated heat.
The reaction was instant and violent. The magnesium hissed like an angry cat. The blue solution boiled around the metal, turning pale within seconds. But unlike the zinc, the magnesium didn’t just produce a dusting of copper. It became coated in a hot, fizzing blanket of reddish-brown powder. The test tube grew warm to the touch. chemistry form 4 experiment 5.1
Maya stood up, her voice steady. “Magnesium is the most reactive, then zinc, then copper. Because a more reactive metal will displace a less reactive metal from its salt solution.”
Ravi carefully dropped a few granules of zinc into the next tube. For a moment, nothing. Then, a miracle. The deep blue colour began to bleed away from the zinc, as if an invisible eraser was moving upwards. Simultaneously, a reddish-brown dust started to bloom on the surface of the zinc granules, like rust forming in fast-forward. In their lab books, under , Maya wrote
The experiment was simple, yet dangerous to a careless hand. Procedure 5.1: Investigate the reaction of metals with the salt solution of another metal.
“Magnesium!” the class shouted.
Lin nodded, swirling the last of the pale, colourless solution down the sink. “That’s not war,” she smiled. “That’s displacement. And now we know how to prove who belongs where.”
It was. The zinc was tearing the copper out of the solution. The chemical equation wrote itself in Maya’s mind: Zinc + Copper(II) sulphate → Zinc sulphate + Copper. The reaction was instant and violent