Answer :
Final answer:
The mass of Ag deposited is calculated using Faraday's laws of electrolysis. By passing 965 amperes for one second and using the Faraday constant, the mass of deposited silver is found to be 1.0787 g. Option c is the answer.
Explanation:
The question is about calculating the mass of silver plated on a cup by electroplating, using a current of 965 amperes for one second. The relationship between the amount of electrical charge passed through a solution and the amount of substance deposited at an electrode is described by Faraday's laws of electrolysis. For silver, with an atomic weight of 107.87, one mole of electrons is required to deposit one mole of silver (Ag+ + e- → Ag(s)).
To solve this, we use the Faraday constant, which is approximately 96500 Coulombs per mole of electrons. By passing a current of 965 amperes for one second, we have passed a total charge of 965 Coulombs. We then calculate the number of moles of electrons using the formula: moles of electrons = total charge / Faraday constant. Once we have the moles of electrons, we can use the atomic weight of silver to find the mass of silver deposited:
moles of electrons = 965 C / 96500 C/mol = 0.01 mol
mass of Ag deposited = moles of electrons * atomic weight of Ag = 0.01 mol * 107.87 g/mol = 1.0787 g
Thus, the correct answer is C. 1.0787 g.