2 thoughts on “If 5 amps of current are used in an electrolytic cell, how long would it take to produce;?

  1. Lancenigo di Villorba (TV), Italy

    The FIRST FARADAY’s LAW affirm that :”the electrical charge flown in an electrical circuit results proportional to mass of the chemical species processed at electrodes”.

    CASE A
    Well, 50 grams of Metallic Sodium results a mass corrensponding to

    50 / 23 = 2.1 atom-grams

    and it arrives from the following half-rection

    Na+ + e —> Na

    Since ONE ELECTRON LEADS TO ONE SODIUM ATOM, the Faraday’s Law is applied on the basis of this “1Electron : 1Sodium” Ratio

    Sodium Atom-grams * 1 = Current * Time
    2.1 * 1 = 5 * Time

    and I get

    Time = 2.1 / 5 = 0.43 s

    CASE B
    Well, 50 grams of Metallic Potassium results a mass corrensponding to

    50 / 39 = 1.3 atom-grams

    and it arrives from the following half-rection

    K+ + e —> K

    Since ONE ELECTRON LEADS TO ONE POTASSIUM ATOM, the Faraday’s Law is applied on the basis of this “1Electron : 1Potassium” Ratio

    Potassium Atom-grams * 1 = Current * Time
    1.3 * 1 = 5 * Time

    and I get

    Time = 1.3 / 5 = 0.26 s

    I hope this helps you.

  2. Zor is forgetting to use the Faraday constant (F) 96.5 C/mol e-.

    a) 50g of Na is 2.17 mol Na. To produce 2.17 mol of Na from Na+ will take 2.17×96.5 = 210 coulombs.

    now #coulombs = current x time, so

    time = 210/5 = 42.0 seconds

    b) 50g of Mg is 2.06 mol Mg. To produce this from Mg2+ will take 2×2.06×96.5 = 397 coulombs (since it takes two mol e- to produce one mol Mg)

    so

    time = 397/5 = 79.4 s

    edit: My mistake F is 96500 C/mol e-. So the answers are 1000 times larger a) is 43000 s or 11.9 hours and b) is 79400s or 66.2 hours.

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