Nernst equation – for the following reaction:
mn (s) + cr3+ (aq) ? mn2+ (aq) + cr (s)
(a) write the three balanced equations (each half-cell and the overall):
(b) what is the standard cell potential (e°cell) for this mn/cr cell?
(c) what will be the cell potential when [mn2+] = 0.20 m and [cr3+] = 1.0 × 10-4 m ?
(d) what will be the cell potential when [mn2+] = 1.0 × 10-4 m and [cr3+] = 0.20 m ?

For a: The reactions are written below.

For b: The standard cell potential of the given cell is +0.44 V.

For c: The cell potential for the given values is 0.408 V

For d: The cell potential for the given values is 0.4724 V.

Explanation:

The given cell is:

Half reactions for the given cell follows:

Oxidation half reaction:       (  ×  3)

Reduction half reaction:       (  ×  2)

Net reaction:

Oxidation reaction occurs at anode and reduction reaction occurs at cathode.

To calculate the of the reaction, we use the equation:

Putting values in above equation, we get:

Hence, the standard cell potential of the given cell is 0.44 V

To calculate the EMF of the cell, we use the Nernst equation, which is:

where,

= electrode potential of the cell = ?V

= standard electrode potential of the cell = +0.44 V

n = number of electrons exchanged = 6

Putting values in above equation, we get:

Hence, the EMF of the cell for the given concentration is 0.408 V.

To calculate the EMF of the cell, we use the Nernst equation, which is:

where,

= electrode potential of the cell = ?V

= standard electrode potential of the cell = +0.44 V

n = number of electrons exchanged = 6

Putting values in above equation, we get:

Hence, the EMF of the cell for the given concentration is 0.4724 V.

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.