Name: Redox Reactions as a Basis for Titration
Uploaded: 2019-07-19
Duration: 7 min 17 s
Description: This video will help us learn about how redox indicators like potassium permanganate or diphenylamine are used to indicate the completion of a redox reaction...

Question

Draw a labelled diagram for the Daniel cell. Discuss its working.

Accepted Answer

The labelled diagram of Daniel cell is shown below:

Working-

Left Beaker: Zinc rod starts dissolving and zinc sulphate solution becomes more concentrated. Each zinc atom loses two electrons to form ${Zn}^{2 +} (aq)$ ions. The zinc ions then migrate away from the rod into solution while the electrons move through the wire, via voltmeter and ultimately reach the copper rod. The change taking place may be represented as:

$Zn (s) \to Zn (aq) + 2 e^{-} \dots \dots \dots \dots \dots \dots \dots (i)$

Right Beaker: Copper sulphate solution starts getting more diluted and metallic copper starts depositing, so electron released by zinc atoms in the left beaker on reaching the copper rod combine with ${Cu}^{2 +} (aq)$ ions present in the solution to form neutral copper atom which gets deposited on the copper rod. The change taking place may be represented as :

${Cu}^{2 +} (aq) + 2 e^{-} \to Cu (s) \dots \dots \dots \dots \dots \dots \dots (ii)$

The overall reaction taking place in two beakers is

$Zn (s) + {Cu}^{2 +} (aq) \to {Zn}^{2 +} (aq) + Cu (s)$

Draw a labelled diagram for the Daniel cell. Discuss its working.

Important Questions on Redox Reactions

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