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The town of Natrium, West Virginia, derives its name from the sodium produced in the electrolysis of molten sodium chloride (NaCl) mined from ancient salt deposits. The number of kilowatt-hours of electricity required to produce 4.50 kg of metallic sodium from the electrolysis of molten NaCl(s) is ________ when the applied emf is 5.00 V.

Respuesta :

Explanation:

The reaction equation will be as follows.

           [tex]Na^{+} + e^{-} \rightarrow Na(s)[/tex]

Hence, moles of Na = moles of electron used

Therefore, calculate the number of moles of sodium as follows.

       No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]

                             = [tex]\frac{4500 g}{23 g/mol}[/tex]    (as 1 kg = 1000 g)

                             = 195.65 mol

As,     Q = [tex]n \times F[/tex]       where F = Faraday's constant

              = [tex]195.65 mol \times 96500 C[/tex]

              = [tex]1.88 \times 10^{7}[/tex] mol C

Relation between electrical energy and Q is as follows.

               E = [tex]Q \times V[/tex]

Hence, putting the given values into the above formula and then calculate the value of electricity as follows.

              E = [tex]Q \times V[/tex]

                 = [tex]1.88 \times 10^{7} \times 5[/tex]

                 = [tex]9.4 \times 10^{7} J[/tex]

As 1 J = [tex]2.77 \times 10^{-7}[/tex] kWh

Hence,      [tex]\frac{9.4 \times 10^{7}}{2.77 \times 10^{-7}}[/tex] kWh

                = 3.39 kWh

Thus, we can conclude that 3.39 kilowatt-hours of electricity is required in the given situation.