Electrolysis

Question

Answer

What is the half equation for sodium losing an electron?

Na → Na⁺ + e⁻

What is the half equation for chlorine gaining electrons?

Cl₂ + 2e⁻ → 2Cl⁻

What is the general equation for a metal reacting with acid?

Metal + Acid → Salt + Hydrogen

What is the general equation for a metal oxide reacting with acid?

Metal oxide + Acid → Salt + Water

What is the general equation for a metal carbonate reacting with acid?

Metal carbonate + Acid → Salt + Water + Carbon dioxide

What is the ionic half equation for hydrogen being produced?

2H⁺ + 2e⁻ → H₂

What is the ionic half equation for copper being reduced from a solution?

Cu²⁺ + 2e⁻ → Cu

What is the ionic half equation for zinc being oxidised?

Zn → Zn²⁺ + 2e⁻

What is the general reaction of a metal and water (for reactive metals)?

Metal + Water → Metal hydroxide + Hydrogen

What happens in oxidation?

Electrons are lost

What happens in reduction?

Electrons are gained

What is the mnemonic for oxidation and reduction?

OIL RIG – Oxidation Is Loss, Reduction Is Gain

How do you extract a metal below carbon in the reactivity series?

By reduction using carbon

How do you extract a metal above carbon in the reactivity series?

By electrolysis

Why do ionic compounds need to be molten or dissolved for electrolysis?

So the ions are free to move and carry charge