What is the overall cell potential for this redox reaction? cd + hg22+ → cd2+ + 2hg given: cd2+ + 2e− → cd(s) = –0.40 and hg22+ + 2e− → 2hg(l) = 0.79 –0.19 v 0.19 v 0.91 v 1.19 v

 1.19 V

Explanation:

Standard potential for an electrochemical cell is given by:

= standard electrode potential =

The values have to be reduction potentials.  

Given:

Cadmium is losing electrons , undergo oxidation and thus act as anode. mercury is gaining electrons, undergo reduction and thus acts as cathode.

= standard electrode potential =

Thus the standard potential for an electrochemical cell with the cell reaction is 1.19 V.

The overall cell potential for this redox reaction : 1.19V

Cd + Hg₂²⁺ → Cd²⁺ + 2Hg

Cell potential (E °) is the potential difference between the two electrodes in an electrochemical cell.

Electric current moves from a high potential pole to a low potential, so the cell potential is the difference between an electrode that has a high electrode potential (cathode) and an electrode that has a low electrode potential (anode)

or:

E ° cell = E ° reduction-E ° oxidation

(At the cathode the reduction reaction occurs, the anode oxidation reaction occurs)

The value of E⁰ cells uses a reference electrode which is used as a comparison called the Standard Electrode which is the hydrogen-platinum electrode

In reaction:

Cd + Hg₂²⁺ → Cd²⁺ + 2Hg

Given:

Cd²⁺+ 2e⁻ → Cd (s) = –0.40V and

Hg²⁺ + 2e⁻ → 2Hg (l) = 0.79V

From the value of E ° cells, it can be seen that the higher E ° cells will act as positive poles or cathodes namely Hg₂²⁺

So the reaction happens

at the anode (oxidation reaction) Cd ------> Cd²⁺ + 2e⁻ E ° = +0.40 V

at the cathode (reduction reaction) Hg₂²⁺ + 2e− → 2Hg (l) = 0.79 V

E ° cell = E ° cathode -E ° anode = 0.79 V - (-0.40V) = 1.19V

The standard cell potential

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Keywords: cell potential, cathode, anode, reduction, oxidation

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.