Final answer:
To find the number of faradays required to plate 10g of silver from an aqueous NaCl solution, the mass of silver is divided by its molar mass to get the moles of silver, which also corresponds to the moles of electrons needed. Since one faraday is equal to one mole of electrons, 10 g of silver would theoretically require 0.0927 faradays. However, more details are needed to give a precise number.
Step-by-step explanation:
To determine how many faradays of electricity are required for the electrolysis of aqueous NaCl using a 10g Ag cathode, we need to consider the electroplating process. The reaction at the cathode during electroplating is Ag+ (aq) + e− → Ag(s). For every mole of Ag+ ions reduced to Ag(s), one mole of electrons is required, which is equivalent to one faraday of charge (96,485 coulombs).
Silver has a molar mass of approximately 107.87 g/mol. To plate 10 g of silver, the number of moles of Ag plated is the mass over molar mass, which is 10 g / 107.87 g/mol ≈ 0.0927 mol. This means that 0.0927 moles of electrons are needed, which corresponds to 0.0927 faradays of electricity. However, since typically electroplating involves the transfer of an integer number of moles of electrons, the student might have meant that 10 g of silver is the increment in mass after electroplating, possibly requiring a whole number of faradays. It would be necessary to further clarify the specifics of the question to provide a precise number of faradays needed.
According to the information provided in example 16.9, if a current of 10.23 A was passed for exactly 1 hour, the amount of coulombs and the mass of silver deposited can be calculated, but this data cannot be directly applied to the original question without knowing the specific current and time used in the student's scenario.