Metal Displacement Reactions & Redox Flashcards

All 7 cards in this deck

What is a displacement reaction of metals?

A more reactive metal takes the place of a less reactive metal in its compound (solution).

In terms of electrons, what are oxidation and reduction?

Oxidation is loss of electrons; reduction is gain of electrons (OIL RIG).

What are the steps to identify what is oxidised and reduced in a metal displacement reaction?

e.g. zinc + copper sulfate solution

1. The metal added loses electrons → oxidised: $Zn \rightarrow Zn^{2+} + 2e^-$
2. The metal ion in solution gains electrons → reduced: $Cu^{2+} + 2e^- \rightarrow Cu$
3. State both: zinc is oxidised, copper ions are reduced.

What is a redox reaction?

A reaction in which oxidation and reduction happen at the same time.

True or false? In the reaction between zinc and copper sulfate solution, the sulfate ions are reduced.

False. The sulfate ions are spectator ions; the copper ions are reduced.

How can displacement reactions in salt solutions be used to order three metals by reactivity?

Place each metal in solutions of the other metals' salts; the metal showing the greatest number of reactions is the most reactive.

What is seen when excess zinc is added to blue copper sulfate solution?

A red-brown/pink solid forms, some grey solid remains and the blue solution becomes colourless.