Consider an iron nail with silver wrapped onto it, immersed in an agar gel containing phenolphthalein and potassium ferricyanide. After a few minutes a pink colour appeared in the gel around the silver metal and a blue colour was observed in the gel near the tip and head of the iron nail. What is the most accurate interpretation of these observations?

Question

Accepted Answer

Iron is oxidised, producing Fe 2+ (aq) at the tip and head of the nail. Oxygen is reduced at the silver to produce OH – (aq).

Answer

Iron is oxidised producing Fe 2+ (aq) at the tip and head of the nail. Ag + (aq) is reduced producing silver metal.

Answer

Silver is oxidised producing Ag + (aq). Water is reduced at the iron nail to produce OH – (aq).

Answer

Silver is oxidised, producing Ag + (aq). Oxygen is reduced at the silver to produce OH – (aq).

Answer

Iron is oxidised  at the tip and head of the nail, producing Fe 2+ (aq). Water is reduced at the silver to produce OH – (aq).

Crowdly

Consider an iron nail with silver wrapped onto it, immersed in an agar gel conta...

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