Quantitative Electrochemical Calculation can be used to determine which quantities?

Quantitative Electrochemical Calculation can be used to determine which quantities?

• A. Amps
• B. Time
• C. Moles
• D. Amps, Time, Moles, and Grams

Answer: (D)

Quantitative electrochemical calculations use Faraday’s laws to connect electrical charge to the amount of substance that reacts or deposits. The charge passed through an electrochemical cell is the product of current and time, Q = I t, so knowing any two of these values lets you find the third. The amount of material involved relates to charge through n = Q/(n_e F), where n_e is the number of electrons transferred per formula unit and F is Faraday’s constant. From there, converting moles to grams is simply multiplying by the molar mass. Because these relationships tie together current, time, moles, and mass, you can determine amps, time, moles, and grams from electrochemical data. For example, depositing copper (which requires 2 electrons per Cu atom) gives n_Cu = Q/(2F) and mass m = n_Cu × M_Cu.

Quantitative electrochemical calculations use Faraday’s laws to connect electrical charge to the amount of substance that reacts or deposits. The charge passed through an electrochemical cell is the product of current and time, Q = I t, so knowing any two of these values lets you find the third. The amount of material involved relates to charge through n = Q/(n_e F), where n_e is the number of electrons transferred per formula unit and F is Faraday’s constant. From there, converting moles to grams is simply multiplying by the molar mass. Because these relationships tie together current, time, moles, and mass, you can determine amps, time, moles, and grams from electrochemical data. For example, depositing copper (which requires 2 electrons per Cu atom) gives n_Cu = Q/(2F) and mass m = n_Cu × M_Cu.