Question

What mass of silver is deposited on the cathode of an electrolytic cell if an electric current of 2.86 A is run through a solution of AgNO3 for one hour? Select one: O a. 11.5 g O b. 5.76 g O c. Og O d. 0.11 g o e. 0.192 g

Answer 1

Electrolysis equation is:

Ag1+ + 1e- ------> Ag

1 mol of Ag requires 1 mol of electron

1 mol of electron = 96485 C

So,1 mol of Ag requires 96485 C

let us calculate the charge passed:

t = 1.0 hr = 1.0*3600 s = 3.6*10^3 s

time, t = 3.6*10^3s

Q = I*t

= 2.86A * 3.6*10^3s

= 1.03*10^4 C

mol of Ag plated = 1.03*10^4/96485 = 0.1067 mol

Molar mass of Ag = 1.079*10^2 g/mol

mass of Ag = number of mol * molar mass

= 0.1067 * 1.079*10^2

= 11.51 g

Answer: a