Answer
0.022 mol
Work Step by Step
Given half reaction is $Au^{3+}$ (aq) + 3e- ---> Au(s)
So, we can conclude that 3 mol of electrons can be used to electroplate 1 mole of Au.
1 mol of Au= 196.9 g
So to electroplate 1.4g of Au, number of moles electrons required is:
= 1.4 g x( 3 mole of electrons/ 196.9 g )
= 0.022 mol
