Galvanic cells

The diagram shows an electrochemical cell designed to find the standard electrode potential for zinc.

Name the apparatus labelled B and give its two functions :

• Electrode; maintains an ionic balance in the two half‑cells and completes the circuit

   

• salt bridge; maintains the voltage in the two half‑cells and completes the circuit

• Electrode; flow electron from anode to cathode  and completes the circuit

• salt bridge; maintains an ionic balance in the two half‑cells and completes the circuit

The diagram shows an electrochemical cell designed to find the standard electrode potential for zinc.

Show the sign for platinum electrode in diagram above:

• A

• B

• C

• D

1.     A student constructs a voltaic cell using tin and lead electrodes immersed in 1moldm−3 solutions of tin(ii) and lead(ii) ions. What is the EMF for the spontaneous reaction? The electrode potentials are:

Sn²⁺(aq) + 2e⁻ → Sn(s)            E⁰ = −0.14V

Pb²⁺(aq) + 2e⁻ → Pb(s)            E⁰ = −0.13V

• −0.27V

   

• −0.01V

•  +0.01V

   

• +0.27V

Given the standard reduction potentials :

• nickel ions with cadmium ions

• nickel atoms with cadmium ions

     

• nickel ions with hydrogen ions   

• cadmium atoms with nickel ions

Use the following standard electrode potentials to calculate the cell potential when an Fe³⁺|Fe²⁺ half-cell is connected to a Cl₂|Cl⁻ half-cell:

•    −0.18V

   

• +2.13V

• +0.59V

•  +0.09V

Consider the following standard electrode potentials:

From these data it can be deduced that:

• Co is a stronger reducing agent than Mn

• Pb²⁺ is a stronger oxidising agent than Pd²⁺

      

• Mn is a stronger reducing agent than Pd

• Co²⁺ is a stronger reducing agent than Mn²⁺

The list below gives the standard electrode potentials for five half-reactions.

Which species in the list is  the strongest oxidising agent?

• A.    Cu²⁺

• Fe²⁺

   

• Fe³⁺

•   I₂

The list below gives the standard electrode potentials for five half-reactions.

Which species in the list is the strongest reducing agent? 

•    Zn

•   I^-   

•   Fe²⁺  

• Fe

Use the following standard electrode potentials to decide which reaction will be spontaneous:

• UO²⁺+ 4H⁺ +2Po²⁺ → U⁴⁺+ 2H₂O + 2Po

• 2Cr + 3Po²⁺ → 2Cr³⁺ + 3Po

   

• Re + 4H₂O + 7Cr³⁺ → ReO₄⁻+ 8H⁺ + 7Cr²⁺

     

• 3U⁴⁺ + 6H₂O + Cr³⁺ → Cr + 3UO²⁺ + 12H⁺