Electrolysis

What does the term electrolysis mean?

The breakdown of a molten or aqueous ionic compound using electricity ( an electric current being passed through)

What is the cathode and anode?

Cathode - negatively charged electrode

Anode - positively charged electrode

What is an electrolyte?

• ionic compound in the molten or aqueous state that undergoes electrolysis

• ions in the electrolyte are able to move freely and are attracted to the electrode with an opposite charge

What is formed at each electrode in electrolysis?

Positive electrode: non metal

Negative electrode: metal or hydrogen

How can you predict whether a metal or hydrogen will form at the negative electrode during electrolysis of an aqueous compound?

• if the metal is less reactive than hydrogen in the reactivity series then the metal will form

• If the metal is more reactive than hydrogen will form

What forms at each electrode during electrolysis of molten lead(II) bromide

Anode: bromine

Cathode: lead

What firms at each electrode during the electrolysis of concentrated hydrochloric acid?

Anode: chlorine

Cathode: hydrogen

What forms at each electrode during the electrolysis of concentrated sodium chloride solution NaCl (aq)?

Anode: chlorine 8halide ion will form its halogen)

Cathode: hydrogen (sodium is more reactive)

What forms at each electrode during the electrolysis of dilute sulfuric acid H2SO4 (aq)

Anode: oxygen

Cathode: hydrogen

How can the products of electrolysis of molten electrolytes be predicted?

Anode: non-metal element

Cathode: metal element

Predict what forms at each electrode during the electrolysis of molten zinc chloride

Anode: chlorine

Cathode: zinc

Predict the products of electrolysis of concentrated potassium bromide solution

Anode: bromine

Cathode: hydrogen