Constants Periodic Table Part A When electricity (the flow of electrons) is pass
ID: 1031270 • Letter: C
Question
Constants Periodic Table Part A When electricity (the flow of electrons) is passed through a solution, it causes an oxidation-reduction (redox) reaction to occur. If the solution contains a metal cation such as Ag, the flow of electrons will reduce the silver ion, causing solid silver to plate onto the electrode. The amount of metal plated depends on the number of electrons passed What mass of Cu(s) is electroplated by running 17.5 A of current through a Cu2+ (aq) solution for 4.00 h? Express your answer to three significant figures and include the appropriate units. View Available Hint(s) The total charge of a mole of electrons is 96,485 coulombs (C) and 1 ampere (A) 1 coulomb/second (C/s) aiie Submit Part B How many minutes will it take to electroplate 24.1 g of gold by running 5.00 A of current through a solution of Au* (aq)? Express your answer to three significant figures and include the appropriate units View Available Hint(s) Value UnitsExplanation / Answer
A)
Electrolysis equation is:
Cu2+ + 2e- ------> Cu
1 mol of Cu requires 2 mol of electron
1 mol of electron = 96485 C
So,1 mol of Cu requires 192970 C
let us calculate the charge passed:
t = 4.0 hr = 4.0*3600 s = 14400 s
time, t = 14400s
Q = I*t
= 17.5A * 14400s
= 252000 C
mol of Cu plated = 252000/192970 = 1.3059 mol
Molar mass of Cu = 63.55 g/mol
mass of Cu = number of mol * molar mass
= 1.3059 * 63.55
= 83.0 g
Answer: 83.0 g
B)
Electrolysis equation is:
Au1+ + 1e- ------> Au
1 mol of Au requires 1 mol of electron
1 mol of electron = 96485 C
So,1 mol of Au requires 96485 C
let us calculate mol of element deposited:
use:
number of mol, n = mass/molar mass
= 24.1/197
= 0.12234 mol
total charge = mol of element deposited * charge required for 1 mol
= 0.12234*96485
= 11803.4949 C
use:
time = Q/i
= 11803.4949/5
= 2360.699 seconds
= 2360.699/60 min
= 39.3 min
Answer: 39.3 min